Below are copies of abstracts from the NIH database. Click on a heading below to see abstracts of articles on that topic:


Irritant contact stomatitis: a review of the condition.


[OI1]1: J Periodontol 1998 Jun;69(6):620-31

Davis CC, Squier CA, Lilly GE

Regulatory and Clinical Development, The Procter & Gamble Company, Cincinnati, OH, USA. davis.cc@pg.com

Several different types of interactions are possible between a chemical, a mixture of chemicals, and associated extrinsic factors (i.e., mechanical irritation) in the oral mucosa. These interactions can be broadly classified as irritative or allergenic in nature. In each case, the pathology usually includes mucosal inflammation. The information compiled and reviewed in this article suggests that, given the broad definition of surface lesions/mucosal abnormalities, there may be a continuum of irritation that can be termed "irritant contact stomatitis." This may be due to the fact that the mouth is lined with highly vascular mucosa that turns over rapidly compared to the skin, and may or may not be covered by keratin. Some regions in the mouth are uniquely sensitive to irritants because they can penetrate through the tissue easily. Key factors involved in the potential development of irritation are: inherent irritation potential of the agent, amount of exposure (concentration, duration, and frequency), ability to penetrate the tissue, and inherent reactivity of the subject as well as other extrinsic factors. Irritation leading to oral mucosal alterations is a common occurrence caused by a wide variety of exposures and insults to the oral cavity. Various irritants such as foods, chemicals, friction, thermal/mechanical injury, metals, spices, and oral care products have been documented to cause irritant reactions in susceptible individuals, particularly if used under exaggerated exposure conditions. It is important to note that most irritation in the oral cavity tends to reverse quickly when the causative agent is removed. Oral irritation is a commonly occurring phenomenon. Thus, it is important that the clinician be aware of the clinical manifestations and etiology of the condition.

Intraoral contact allergy: a literature review and case reports.


[OI2]1: J Am Dent Assoc 1998 Oct;129(10):1435-41

De Rossi SS, Greenberg MS

Department of Oral Medicine, University of Pennsylvania, School of Dental Medicine, Philadelphia 19104, USA.

Signs and symptoms of contact allergic reactions affecting the oral mucosa may mimic other common oral disorders,making diagnosis difficult. Patients frequently seek multiple consultations and do not receive the correct diagnosis or effective management. As intraoral contact allergy may be more prevalent than previously believed, a review of this topic is warranted. This article emphasizes signs and symptoms that suggest intraoral contact allergy, and the authors discuss the allergens that most frequently affect the oral mucosa


Antimicrobial treatment of periodontal diseases disturbs the human ecology: a review.


[OC1]1: J Chemother 1996 Oct;8(5):331-41

Edlund C, Hedberg M, Nord CE

Department of Immunology, Microbiology, Pathology and Infectious Diseases, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden.

Periodontal diseases are associated with specific pathogenic microorganisms and therefore antimicrobial agents are often used in the treatment of patients with periodontitis refractory to conventional mechanical therapy. Perorally administered antimicrobial agents often lead to ecological disturbances in the normal oral and intestinal microflora with overgrowth of potentially pathogenic microorganisms, which may spread within the host or from patient to patient, causing infections. The use of antimicrobial agents also promotes the emergence of bacterial drug resistance, both in the periodontal pocket and in the normal oral and intestinal microflora. Topical administration of antimicrobial agents in the periodontal pockets causes restricted disturbances in the intestinal microflora, although there is a substantial risk of development of resistance at the site of application. A number of clinical studies imply that correct use of antimicrobial agents might be beneficial for a subset of patients with adult or juvenile periodontitis. The choice of antimicrobial agent should always be based on accurate microbial analyses of the subgingival microflora and in vitro antimicrobial susceptibility tests of the most important periodontal pathogens. Preferably, agents with low potential of causing ecological disturbances should be used.

Chemically induced inflammation in rat oral mucosa.


[OC2]1: Scand J Dent Res 1988 Oct;96(5):428-34

Ahlfors EE, Larsson A

Department of Oral Pathology, University of Lund, Malmo, Sweden.

The toxic, irritative, and sensitizing effects of topically applied sodium lauryl sulfate (SLS), dithranol triacetate (DTA), nonanoic acid in methyl- or propyl ester (NAM, NAP) in the buccal mucosa were investigated in a Sprague-Dawley rat model. Semi-quantitative evaluations of cellular infiltrates were performed in routine histologic preparations. The toxic potential was tested with 2% and 0.2% solutions. All substances, except 0.2% SLS, caused an increased cellularity, mainly of a mononuclear cell type. The low dose of NAM induced stronger inflammatory reactions than the high dose. Repeated applications of 2% solutions decreased the response compared to one application, except for NAM, where a clear irritative potential was observed. Pre-exposure of dorsal skin prior to buccal painting resulted in an enhanced reaction to NAM and NAP, whereas no sensitizing capacity was noted in SLS or DTA in this model.

Sodium lauryl sulfate (SLS) induced irritant contact dermatitis: a correlation study between ceramides and in vivo parameters of irritation.

[OC3]: Contact Dermatitis 1996 Aug;35(2):86-91

di Nardo A, Sugino K, Wertz P, Ademola J, Maibach HI

Department of Dermatology, University of Modena, Italy.

Sodium lauryl sulfate (SLS), a surfactant frequently used in the induction of experimental irritant contact dermatitis in animals and in humans, characteristically induces a dose-related increase in TEWL (transepidermal water loss). Ceramides are considered to be important in the regulation of the skin barrier. We therefore examined the relationship between initial ceramide content of stratum corneum and induced changes in skin color (erythema) and barrier function, after SLS application under occlusion (1% and 3% in water) to the forearm of 14 volunteers. Stratum corneum sheets were removed, stratum corneum lipids extracted, and ceramide composition determined from chromatograms (TLC) using densitometry. After determining baseline skin color and TEWL at each area, 2 samples of stratum corneum were obtained from each volunteer. Clinical and instrumental controls of the SLS-induced irritation were performed at 24, 48, 72 and 96 h. Erythema was evaluated by colorimetry: barrier impairment by changes in TEWL. We found inverse correlations between baseline ceramide 61 (weight) and the 24 h erythema score for SLS 3%, between ceramide 1 and 24 h TEWL, and between ceramide 611 and 72 h TEWL for SLS 3%. Our findings suggest that low levels of these ceramides may determine a proclivity to SLS-induced irritant contact dermatitis.

PMID: 8917825, UI: 97075434

Extensive oral mucosal ulcerations caused by misuse of a commercial mouthwash.


1: Cutis 1999 Aug;64(2):131-4

Moghadam BK, Gier R, Thurlow T

Department of Diagnostic Sciences, University of Missouri-Kansas City School of Dentistry, Kansas City 64108, USA.

This case report describes severe mucosal injuries following misuse of an undiluted over-the-counter mouthwash with a high alcohol content (70%), oil of peppermint and arnica. The mouthwash was to be diluted 5:1 with water. The patient used undiluted solution to better treat her self-diagnosed "contagious gum infection." She experienced burning sensation with each rinse and developed severe mucosal injuries subsequently. Her oral condition improved within 48 hours following discontinuation of use of the mouthwash and application of a mixture of Benadryl Elixir, Maalox Plain, and 2% viscous Lidocaine. A detailed history and review of a patient's medical condition will help to differentiate self-induced mucosal injuries from those caused by an allergic reaction or skin diseases.

PMID: 10467509, UI: 99396840

The effects of tartar-control toothpaste on the oral soft tissues.

AUTHORS: Kowitz G; Jacobson J; Meng Z; Lucatorto F

AUTHOR AFFILIATION: Department of Oral Medicine, Oral Pathology, Oral Diagnosis, School of Dentistry, UCLA Center for Health Sciences.

SOURCE: Oral Surg Oral Med Oral Pathol 1990 Oct;70(4):529-36


Ninety-two dental and dental hygiene students completed a double-blind, controlled clinical trial. The purpose of the trial was to evaluate the effects of toothpastes, in varying concentrations of flavor and tartar-control agents. Four formulations of toothpastes were assessed: (A) control-low flavor with no tartar control; (B) medium flavoring with medium tartar control; (C) high flavoring with medium tartar control; and (D) medium flavoring with no tartar control. Soft tissue reactions were assessed objectively and independently by three examiners. Subjective perceptions about each toothpaste were gathered by a structured, open-ended questionnaire. The "tartar control" toothpastes, B and C, resulted in statistically significant (p less than 0.005) higher rates of mucosal reactions (e.g., ulceration, sloughing, erythema, migratory glossitis) than the "non-tartar control" toothpastes A and D. When the oral mucosal reaction rates were adjusted for multiple clinical observations within each subject at the same point in time there was no statistically significant (p greater than 0.05) difference between male (0.25) and female (0.28) subjects. In this study population, the order of preference was observed as toothpaste A greater than D greater than B greater than C. The major reasons for disfavor were burning sensation in toothpastes C (2.4%) and B (4%).

Skin reactions and irritation potential of four commercial toothpastes.

AUTHORS: Skaare A; Kjaerheim V; Barkvoll P; Rolla G

AUTHOR AFFILIATION: Department of Oral Surgery and Oral Medicine, Faculty of Dentistry, University of Oslo, Norway.

SOURCE: Acta Odontol Scand 1997 Apr;55(2):133-6


Skin reactions to 4 toothpastes were tested in 19 healthy dental students in a double-blind study. The hypothesis was that common toothpaste brands with and without sodium lauryl sulfate (SLS) and triclosan and with different additives/emulgators differ in irritation potential. An occlusion test system on human skin was used. The toothpastes tested were A) Zendium (non-ionic detergent), B) Solidox F (SLS/polyethylene glycol), C) Colgate Total (triclosan/copolymer/SLS/propylene glycol), and D) Solidox G (triclosan/zinc citrate/SLS/polyethylene glycol). Toothpaste C was the greatest irritant, causing skin erythema in 16 of the 19 subjects, whereas toothpaste D gave no reactions. Toothpaste B provoked three reactions (two severe), whereas toothpaste A caused only one mild reaction. Although this study was carried out on skin and hence not directly applicable to the oral cavity, these and previous results may indicate that a toothpaste without propylene glycol and SLS may be preferred by susceptible persons.


U.S. Food and Drug Administration perspective of the inclusion of effects of low-level exposures in safety and risk assessment.


[PS1]1: Environ Health Perspect 1998 Feb;106 Suppl 1:391-4

Gaylor DW, Bolger PM, Schwetz BA

National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079-9502, USA. dgaylor@nctr.fda.gov

A brief overview is provided of some of the general safety and risk assessment procedures used by the different centers of the U.S. Food and Drug Administration (U.S. FDA) to evaluate low-level exposures. The U.S. FDA protects public health by regulating a wide variety of consumer products including foods, human and animal drugs, biologics, and medical devices under the federal Food, Drug, and Cosmetic Act. The diverse legal and regulatory standards in the act allow for the consideration of benefits for some products (e.g., drugs) but preclude them from others (e.g., food additives). When not precluded by statutory mandates (e.g., Delaney prohibition), the U.S. FDA considers both physiologic adaptive responses and beneficial effects. For the basic safety assessment paradigm as presently used, for example in the premarket approval of food additives, the emphasis is on the identification of adverse effects and no observed adverse effect level(s) (NOAEL). Generally, the NOAEL is divided by safety factors to establish an acceptableexposure level. This safety assessment paradigm does not preclude the consideration of effects whether they are biologically adaptive or beneficial at lower dose levels. The flexibility to consider issues such as mechanisms of action and adaptive and beneficial responses depends on the product under consideration. For carcinogenic contaminants and radiation from medical devices, the U.S. FDA considers the potential cancer risk at low exposure levels. This generally involves downward extrapolation from the observed dose-response range. The consideration of adverse effects of other toxicologic end points (e.g., reproductive, immunologic, neurologic, developmental) associated with low exposure levels is also becoming more of a reality (e.g., endocrine disrupters). The evaluation of the biologic effects of low-level exposures to toxic substances must include whether the effect is adverse or a normal physiologic adaptive response and also determine the resiliency of a physiologic system. The public health mandate of the U.S. FDA includes an active research program at the National Center for Toxicological Research and the other U.S. FDA centers to support the regulatory mission of the U.S. FDA. This includes the development of knowledge bases, predictive strategies, and toxicologic studies to investigate effects at the lower end of the dose-response range. Because of the wide diversity of legal and regulatory standards for various products regulated by the U.S. FDA agency-wide safety and risk assessment procedures and policies generally do not exist.

Threshold of toxicological concern for chemical substances present in the diet: a practical toolfor assessing the need for toxicity testing.


[FS2]1: Food Chem Toxicol 2000 Feb-Mar;38(2-3):255-312

Kroes R, Galli C, Munro I, Schilter B, Tran L, Walker R, Wurtzen G

RITOX-Utrecht University, Faculty of Veterinary Medicine, PO Box 80176, 3508 TD Utrecht, The Netherlands.

The de minimis concept acknowledges a human exposure threshold value for chemicals below which there is no significant risk to human health. It is the underlying principle for the US Food and Drug Administration (FDA) regulation on substances used in food-contact articles. Further to this, the principle of Threshold of Toxicological Concern (TTC) has been developed and is now used by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in their evaluations. Establishing an accepted TTC would benefit consumers, industry and regulators, since it would preclude extensive toxicity evaluations when human intakes are below such threshold, and direct considerable time and cost resources towards testing substances with the highest potential risk to human health. It was questioned, however, whether specific endpoints that may potentially give rise to low-dose effects would be covered by such threshold. In this review, the possibility of defining a TTC for chemical substances present in the diet was examined for general toxicity endpoints (including carcinogenicity), as well as for specific endpoints, namely neurotoxicity and developmental neurotoxicity, immunotoxicity and developmental toxicity. For each of these endpoints, a database of specific no-observed-effect levels (NOELs) was compiled by screening oral toxicity studies. The substances recorded in ach specific database were selected on the basis of their demonstrated adverse effects. For the neurotoxicity and velopmental neurotoxicity databases, it was intended to cover all classes of compounds reported to have either a emonstrated neurotoxic or developmentally neurotoxic effect, or at least, on a biochemical or pharmacological basis ere considered to have a potential for displaying such effects. For the immunotoxicity endpoint, it was ensured that nly immunotoxicants were included in the database by selecting most of the substances from the Luster et al. atabase, provided that they satisfied the criteria for immunotoxicity defined by Luster. For the developmental toxicity database, substances were selected from the Munro et al. database that contained the lowest NOELs retrieved from the literature for more than 600 compounds. After screening these, substances showing any effect which could point to developmental toxicity as broadly defined by the US were recorded in the database. Additionally, endocrine toxicity and allergenicity were addressed as two separate cases, using different approaches and methodology. The distributions of NOELs for the neurotoxicity, developmental neurotoxicity and developmental toxicity endpoints were compared with the distribution of NOELs for non-specific carcinogenic endpoints. As the immunotoxicity database was too limited to draw such a distribution of immune NOELs, the immunotoxicity endpoint was evaluated by comparing immune NOELs (or LOELs-lowest-observed-effect levels-when NOELs were not available) with non-immune NOELs (or LOELs), in order to compare the sensitivity of this endpoint with non-specific endpoints. A different methodology was adopted for the evaluation of the endocrine toxicity endpoint since data currently available do not permit the establishment of a clearcausal link between endocrine active chemicals and adverse effects in humans. Therefore, this endpoint was analysed by estimating the human exposure to oestrogenic environmental chemicals and evaluating their potential impact on human health, based on their contribution to the overall exposure, and their estrogenic potency relative to endogenous hormones. The allergenicity endpoint was not analysed as such. It was addressed in a separate section because this issue is not relevant to the overall population but rather to subsets of susceptible individuals, and allergic risks are usually controlled by other means (i.e. labelling) than the Threshold of Toxicological Concern approach.


Diagnosis of oral ulcers.


[OE1]1: Mt Sinai J Med 1998 Oct-Nov;65(5-6):383-7

Schneider LC, Schneider AE

Department of Oral Pathology, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark

07103, USA.

Ulcers commonly occur in the mouth. Their causes range from minor irritation to malignancies and systemic diseases. Innocent solitary ulcerations, which result from trauma and infections, must be distinguished from squamous cell carcinomas, which also typically present as solitary ulcers. Multiple oral ulcers may be classified as acute, recurrent and/or chronic. The most common causes of rapid-onset oral ulcers include acute necrotizing ulcerative gingivitis, allergies and erythema multiforme. The two common forms of acute (short-term) recurrent oral ulcers, "cold sores" or "fever blisters," which are caused by the herpes simplex virus, and recurrent aphthous ulcers ("canker sores"), may be distinguished largely on the basis of their location. Most types of multiple chronic oral ulcers are associated with disturbances of the immune system. They include erosive lichen planus, mucous membrane pemphigoid and pemphigus vulgaris. Clinical criteria which are most useful in identifying the cause of oral ulcers are vesicles or bullae, which may not be seen because they rupture rapidly in the oral environment; constitutional signs and symptoms; and lesions on the skin and/or other mucosa. In some cases, diagnosis depends upon culture or biopsy, particularly with the application of immunofluorescence to the surgical specimen.

Immunopathogenesis of oral lichen planus and recurrent aphthous stomatitis.

AUTHORS: Eversole LR AUTHOR AFFILIATION: UCLA School of Dentistry, Los Angeles, CA 90095, USA.

SOURCE: Semin Cutan Med Surg 1997 Dec;16(4):284-94

CITATION IDS: PMID: 9421220 UI: 98081573


Oral mucosal bullous/desquamative/ulcerative diseases involve immunopathological mechanisms that account for loss of adhesion between contiguous keratinocytes or to structures within the basal lamina. Some are antibody mediated, in which specific adhesion molecules of the desmosome, hemidesmosome, and basement membrane become antigenic targets. Oral lichen planus and recurrent apthous ulcers, although manifesting disparate clinical appearances and natural history, share immunopathological features that involve T cell-mediated immunity. Although the antigens, haptens, or autoantigens are not usually apparent, current research poses the hypothesis that both of these common oral mucosal diseases are a delayed-type hypersensitivity or cell-mediated response to an antigenic stimulus residing within the epithelium. This article reviews the research evidence for this hypothesis.

Recurrent aphthous ulceration and food sensitivity.


[OE1]1: J Oral Pathol Med 1991 Nov;20(10):473-5

Nolan A, Lamey PJ, Milligan KA, Forsyth A

Department of Oral Medicine and Pathology, Glasgow Dental Hospital and School, Scotland.

Forty patients with recurrent aphthous ulceration (RAU) were investigated to ascertain the possibility of food sensitivity being a significant precipitating factor in their recurrent oral ulceration. All patients were hematologically normal and did not respond to vitamin B1 and B6 therapy. Patch testing (Standard European Series) was undertaken in 21 patients. Twenty patients showed a positive reaction to a number of substances which were considered clinically relevant. Professional advice on avoidance of the allergen was given, resulting in an improvement in eighteen patients. It is concluded that food sensitivity and allergies to other substances should be considered as an etiologic factor in hematologically normal patients with recurrent oral ulceration.

PMID: 1753349, UI: 92092188


Determination of bisphenol A and related aromatic compounds released from bis-GMA-based composites and sealants by high performance liquid chromatography.

[EF1]1: Environ Health Perspect 2000 Jan;108(1):21-7

Pulgar R, Olea-Serrano MF, Novillo-Fertrell A, Rivas A, Pazos P, Pedraza V, Navajas JM, Olea N

Department of Stomatology, School of Odontology, HUSC-University of Granada, Granada, Spain.

Most of the composites and sealants used in dentistry are based on bisphenol A diglycidylether methacrylate (Bis-GMA). Reports revealed that in situ polymerization is not complete and that free monomers can be detected by different analytic methods. Concerns about the estrogenicity of bisphenol A (BPA) and other aromatic components leached from commercial products have been expressed. We studied biphenolic components eluted from seven composites and one sealant before and after in vitro polymerization using HPLC and gas chromatography/mass spectrometry and we investigated how pH modifications affect the leaching of these components. We found BPA (maximal amount 1.8 microg/mg dental material), its dimethacrylate derivative (Bis-DMA, 1.15 microg/mg), bisphenol A diglycidylether (6. 1 microg/mg), Bis-GMA (2.0 microg/mg), and ethoxylate and propoxylate of bisphenol A in media in which samples of different commercial products were maintained under controlled pH and temperature conditions. Our results confirm the leaching of estrogenic monomers into the environment by Bis-GMA-based composites and sealants in concentrations at which biologic effects have been demonstrated in in vivo experimental models. The main issue with implications for patient care and dentist responsibility is to further determine the clinical relevance of this estrogenic exposure.

PMID: 10620520, UI: 20088756

Estrogenicity of bisphenol A and bisphenol A dimethacrylate in vitro.

[EF2] 1: J Biomed Mater Res 1999 Jun 5;45(3):192-7

Schafer TE, Lapp CA, Hanes CM, Lewis JB, Wataha JC, Schuster GS

Department of Pediatric Dentistry, Medical College of Georgia, Augusta, Georgia 30912, USA.

Although pit and fissure sealants have been utilized extensively in dentistry as a way of preventing occlusal caries, results described by Olea et al. (1996) raised concerns about the safety of sealants and other resin-based dental materials due to the reported presence of bisphenol A (BPA) and its dimethacrylate ester (BPA-DM). Although the release of these compounds from dental materials has not been substantiated by two subsequent studies, we believed it was important to confirm or refute the report that BPA and BPA-DM have estrogenic activity in vitro. We grew breast cancer cells (MCF-7, T-47D, ZR-75-1) known to proliferate under estrogenic stimulation in phenol red-free DMEM containing human serum and concentrations of BPA or BPA-DM ranging from 10(-8)M to 5 x 10(-6)M. After 1 week, plates were harvested for crystal violet or sulforhodamine-B assays, and the optical densities of groups of treated cells were compared with values from control cells. At concentrations at or above 10(-6)M, both BPA and BPA-DM significantly increased cell proliferation (p < 0.05), comparable to the increase seen with 10(-9)M of estrogen. Flow cytometric methods demonstrated that these mitogenic effects occurred within 24 h of exposure to estrogen, BPA, or BPA-DM. The increase in DNA synthesis was analogous to that seen with estrogen stimulation. Thus, we confirmed that BPA and BPA-DM cause cell proliferation at micromolar concentrations that exceed the effective concentrations of estrogen by 1 to 10,000-fold. Copyright 1999 John Wiley & Sons, Inc.

PMID: 10397975, UI: 99326635

Estrogenicity of resin-based composites and sealants used in dentistry.

[EF3] 1: Environ Health Perspect 1996 Mar;104(3):298-305

Olea N, Pulgar R, Perez P, Olea-Serrano F, Rivas A, Novillo-Fertrell A, Pedraza V, Soto AM, Sonnenschein C

Department of Radiology, Dentistry, and Department of Nutrition, School of Pharmacy, University of Granada, Spain.

We tested some resin-based composites used in dentistry for their estrogenic activity. A sealant based on bisphenol-A diglycidylether methacrylate (bis-GMA) increased cell yields, progesterone receptor expression, and pS2 secretion in human estrogen-target, serum-sensitive MCF7 breast cancer cells. Estrogenicity was due to bisphenol-A and bisphenol-A dimethacrylate, monomers found in the base paste of the dental sealant and identified by mass spectrometry. Samples of saliva from 18 subjects treated with 50 mg of a bis-GMA-based sealant applied on their molars were collected 1 hr before and after treatment. Bisphenol-A (range 90-931 micrograms) was identified only in saliva collected during a 1-hr period after treatment. The use of bis-GMA-based resins in dentistry, and particularly the use of sealants in children, appears to contribute to human exposure to xenoestrogens.


Cytotoxic effects of extracts of compomers.

[DM1] : Acta Odontol Scand 1999 Dec;57(6):316-22

Sletten GB, Dahl JE

NIOM--Scandinavian Institute of Dental Materials, Haslum, Norway.

We have studied the cytotoxicity of 10 commercially available compomers. Extracts were taken in cell culture medium of non-cured, freshly-cured, and aged samples. Murine L-929 fibroblasts were exposed to the extracts for 24 h and the cytotoxicity was evaluated using dimethylthiazol diphenyltetrazolium (MTT) assay and neutral red uptake (NRU). Extracts were rated as severely, moderately, or slightly cytotoxic when the activity relative to controls was less than 30%, between 30% and 60%, or greater than 60%, respectively. Extracts of non-cured materials were rated severely toxic with both methods, with one exception. All but one freshly-cured material exhibited moderate to severe toxicity in both assays. Aged test specimens were rated moderately to severely toxic. Non-cured materials were generally more toxic than cured, with two exceptions. Aging and polishing the samples to remove non-polymerized surface film affected cytotoxicity to a varying degree. Curing reduced cytotoxicity in the MTT test from severe to moderate in 7 of 9 materials, but had relatively little effect in the NRU assay. Aging and polishing, however, had little effect on cytotoxicity evaluated by the MTT test, but markedly reduced cytotoxicity in NRU in 6 of 8 extracts. To conclude, extracts made from compomers used for dental fillings were found to be cytotoxic both before and after setting.

PMID: 10777134, UI: 20236892

Patterns of cell death induced by eluates from denture base acrylic resins in U-937 human monoblastoid cells.

[[DM2]: Eur J Oral Sci 2000 Feb;108(1):59-69

Cimpan MR, Cressey LI, Skaug N, Halstensen A, Lie SA, Gjertsen BT, Matre R

Institute of Odontology-Department of Dental Biomaterials, Faculty of Dentistry, University of Bergen, Norway.


The purpose of this study was to investigate in vitro the apoptosis- and necrosis-inducing potential of eluates from three heat-polymerized and four autopolymerized poly(methyl methacrylate)-based denture base resins. Our hypothesis was that the rate of cell death by apoptosis and/or necrosis induced by such denture base resins could be an important indicator of their cytotoxicity degree. U-937 human monoblastoid cells were exposed for 24 h and 48 h to eluates of 0.1 g/ml, 0.2 g/ml, 0.4 g/ml, and 0.8 g/ml extracted for 24 h and 48 h. The characteristics of apoptosis and necrosis were evaluated by flow cytometry and light and electron microscopy. Eluates from all resins enhanced cell death by apoptosis and necrosis in U-937 cells in a dose- and time-dependent fashion. Eluates from autopolymerized resins yielded higher percentages of apoptosis and necrosis than the heat-polymerized ones. The results support our hypothesis that eluates of poly(methyl methacrylate)-based denture base acrylic resins activate death-signaling pathways, and that the extent of this process reflects their biocompatibility degree.

PMID: 10706479, UI: 20168996

Leaching and cytotoxicity of formaldehyde and methyl methacrylate from acrylic resin denture base materials.

[DM3]1: J Prosthet Dent 1994 Jun;71(6):618-24

Tsuchiya H, Hoshino Y, Tajima K, Takagi N

Department of Dental Pharmacology, Asahi University, School of Dentistry, Gifu, Japan.

Acrylic resin dentures have the potential to elicit irritation, inflammation, and an allergic response of the oral mucosa. Studies of substances leachable from acrylic resins, their cytotoxicity to cultured cells, and means of reducing their leaching were systematically conducted. Under in vivo and in vitro conditions, formaldehyde and methyl methacrylate were significantly leached into human saliva and saliva-substitute buffer, especially from autopolymerized resins. Both leachable substances showed cytotoxic potentials in the range of their leaching concentrations. Formaldehyde was cytotoxic at lower concentrations than methyl methacrylate. Preleaching in water reduced subsequent leaching of both formaldehyde and methyl methacrylate, and the amount of reduction depended on an increase in the preleaching temperatures. Immersion of acrylic resin dentures in hot water (50 degrees C) before insertion is recommended, especially for autopolymerized resins used either for rebasing or as denture base materials, to minimize the risk of adverse reactions in patients who wear acrylic resin dentures.

PMID: 8040827, UI: 94315560

Biocompatibility of visible light-polymerized denture base resins.

[DM4]1: Int J Prosthodont 1993 Sep-Oct;6(5):495-501

Barron DJ, Schuster GS, Caughman GB, Lefebvre CA

Department of Oral Biology, School of Dentistry, Medical College of Georgia, Augusta 30912.

The biocompatibility of three commercial formulations of visible light-polymerized denture base resins was studied to determine its effects on the RNA and DNA synthesis of oral epithelial cells in vitro. Isotope incorporation into RNA or DNA was measured after 24 hours of incubation with isotope and 48 hours of exposure to resin. The resins were shown to significantly inhibit the synthesis of both nucleotides as compared to a heat-processed resin control. Increasing the polymerization time can mitigate the toxicity of some of the resins. The air barrier coatings used to prevent oxygen inhibition of polymerization increased the toxic effects of two resins and decreased that of one of the materials. These investigations suggest that visible light-polymerized denture resins may impair the replication of oral epithelial cells. DNA synthesis is more sensitive to the toxic effects of the materials, which may relate to the ability to cause mucosal pathology. The cytotoxic effects may relate to the presence of unpolymerized resin constituents or polymerizationby-products.

PMID: 7507674, UI: 94128188

Relationships between denture base resin cytotoxicity and cell lipid metabolism.

[DM5]1: Int J Prosthodont 1995 Nov-Dec;8(6):580-6

Schuster GS, Lefebvre CA, Dirksen TR, Knoernschild KL, Caughman GB

Department of Oral Biology, School of Dentistry, Medical College of Georgia, Augusta, Georgia, USA.

Substances that elute from denture base resins may inhibit cell growth and disrupt various metabolic processes. This study investigated the effects on cell lipid metabolism of eluates from several denture base resins. Cultured oral epithelial cells were exposed in vitro to eluates of discs made from several denture base resins. Lipid metabolism of the cells was measured using isotopic labeling with 14C-acetate. Results demonstrated that the metabolism of several lipid classes found mainly in the cell membrane was altered by the resin eluates. Eluate from one resin caused the appearance of two previously unrecognized classes of lipids. The alterations of the cell lipids and the presence of the previously unrecognized lipids may be the basis for some clinically evident cytotoxic and allergic reactions.

PMID: 8595119, UI: 96177092

The cytotoxic effects of denture base resin sealants.

[DM6]1: Int J Prosthodont 1992 Nov-Dec;5(6):558-62

Lefebvre CA, Schuster GS, Richardson DW, Barron DJ

Department of Prosthodontics, Medical College of Georgia, School of Denistry, Augusta 30912.

Previous studies have shown that light-polymerized denture base resins have a cytotoxic effect on oral epithelial cells. The purpose of this in vitro study was to examine the effects of two denture base resin sealants when used on three light-polymerized denture base resins. Sample disks were examined for their effect on protein synthesis. Results indicate that one sealant protected the cells against toxic effects of the materials (P < .05), while one sealant enhanced toxicity up to 88% above that attributed to the resin alone.

PMID: 1307016, UI: 93326256

[Dental materials--problem substances in allergologic diagnosis? I: Analysis of test results in patients with mouth mucosa/dental material problems].

[DM7]1: Hautarzt 1996 Nov;47(11):839-43

[Article in German] Richter G, Geier J

Klinik und Poliklinik fur Hautkrankheiten, Medizinischen Fakultat Carl Gustav Carus, Technischen Universitat Dresden. Patch testing as a part of the diagnostic evaluation of patients suffering from oral mucosal complaints or with symptoms where dental materials are suspected to be the cause is hampered by numerous difficulties. The ingredients of denture materials as well as their liberation in the oral cavity are often unknown. Contact with many of the potential ingredients of denture materials can occur on other occasions, as well, thus making it difficult to find out where the patient has acquired his or her sensitization. The special morphological and immunological situation in the oral mucosa may produce tolerance of substances which evoke a positive patch test reaction on the skin of the back. This paper introduces the possible spectrum of allergens in these patients and discusses the difficulties in the assessment of the relevance of positive patch test reactions. From August 1992 to July 1994, 756 patients with complaints of the oral mucosa and/or suspected contact allergy to denture materials were patch tested in the departments of dermatology joining the Information Network of Departments of Dermatology in Germany (IVDK). Among these patients, women were overrepresented, while individuals with atopic dermatitis were underrepresented. The allergen spectrum included amalgam, mercury compounds, gold salts, palladium chloride and methyl methacrylate. However, the epidemiologicalvalue of these data is limited. A second part of this paper will review the various groups of allergens.

PMID: 9036137, UI: 97114252

The effect of pH on the cytotoxicity of eluates from denture base resins.

[DM8]: Int J Prosthodont 1995 Mar-Apr;8(2):122-8

Lefebvre CA, Schuster GS, Marr JC, Knoernschild KL

Department of Oral Rehabilitation, School of Dentistry, Medical College of Georgia, Augusta 30912-1250, USA.

This in vitro study examined the effects of environmental pH on elution of potentially toxic substances from heat-, light-, and dual- (chemical plus light) polymerized denture base resins. Eluates were prepared by daily transfer of disks to fresh buffers at pH 4.0, 5.0, and 6.8 over a 5-day period. Oral epithelial cells were plated in culture dishes in medium containing the eluate. After 24 hours, cellular RNA synthesis was assessed by measuring tritiated uridine uptake. Effects of materials were compared to identical cultures that contained the appropriate buffer without the eluate. The results indicate that the cytotoxic components leach out of the denture base resins in different amounts and at different rates, and the amount of leaching can be affected by pH.

PMID: 7575962, UI: 96072503

Leachability of denture-base acrylic resins in artificial saliva.


Koda T, Tsuchiya H, Yamauchi M, Ohtani S, Takagi N, Kawano J

We studied the influence of salivary acidity on leachability of denture-base acrylic resins with etiological interest in denture stomatitis because denture surfaces are frequently exposed to acidic conditions in the oral cavities. Auto-, heat-, and microwave-polymerized resins were immersed in artificial saliva with pH ranging from 4.0 to 6.8 at 37 degrees C, and leachables were pursued quantitatively with time. Methyl methacrylate, methacrylic acid, and benzoic acid leached from all resins. Their concentrations in the saliva were markedly high for auto-polymerized resins, while leachability of heat- and microwave-polymerized resins was so low that quantitative analysis of leachables was impossible. Lower pH showed higher concentrations of methyl methacrylate, although no apparent association was confirmed between salivary acidity and its own leachability. The concentrations of methacrylic acid increased remarkably with an increase in pH, which was probably due to hydrolysis of methyl methacrylate. These results suggest that chemotoxic actions of auto-polymerized resins are potentially ascribable to methyl methacrylate under more acidic conditions and to methacrylic acid under less acidic conditions.

PMID: 2376289, UI: 90330097

Delayed extraoral hypersensitivity to dental composite material.

[DM9]1: Oral Surg Oral Med Oral Pathol 1979 Apr;47(4):329-3

Nathanson D, Lockhart P

Despite their similarities to acrylic resins, composite resins have not been reported to cause allergies. This report documents the case of a patient who experienced several delayed hypersensitivity reactions associated with epoxy-based materials, including dental composite resin. Patch testing confirmed her hypersensitivity to the composite materials. Removal of the composite restorations and replacement with acrylic restorations did not trigger further allergic reactions. Dentists using composite resin materials should be aware of both the possibility of delayed extraoral manifestations of hypersensitivity to those materials and the management of these patients.

PMID: 285401, UI: 79157511

Oral manifestations of gold allergy.

[DM10]1: J Am Acad Dermatol 1994 Feb;30(2 Pt 1):205-9

Laeijendecker R, van Joost T

Department of Dermato-Venereology, Erasmus University, Rotterdam, The Netherlands.

BACKGROUND: Sensitization to gold in a large group of patients suspected of clinical allergy to this metal has not been reported. OBJECTIVE: Two hundred patients with symptoms of persistent oral mucosal or cutaneous lesions that were possibly related to allergy to constituents of gold alloys or gold jewelry were patch tested to determine the frequency of sensitization. METHODS: Patch testing was performed with the European standard series and a series of dental materials including three different salts of gold. A persistent papular reaction to gold-(tri)chloride was considered a positive reaction. RESULTS: In 17 patients (8.5%, all women, mean age 50.2 years) persistent papular patch test reactions to both 0.5% and 1.0% gold(tri)chloride were observed. In five of seven patients with oral lichen planus (OLP) and in one of six patients with the burning mouth syndrome, gold in the dentures was replaced. Particularly in patients with OLP, a significant but variable improvement was observed. In all cases in which gold was replaced and improvement occurred, the patients were sensitized to 0.5% gold(tri)chloride. One patient with allergic contact stomatitis and one patient with allergic contact dermatitis healed completely after gold had been replaced. CONCLUSION: Sensitization to gold should be considered as a possible cause of allergic contact dermatitis and allergic contact stomatitis as well as a pathogenic or triggering factor in OLP.

PMID: 8288779, UI: 94117707

Allergic contact gingivostomatitis from a temporary crown made of methacrylates and epoxy diacrylates.

[DM11]1: Allergy 1999 Dec;54(12):1316-21

Kanerva L, Alanko K, Estlander T

Section of Dermatology, Finnish Institute of Occupational Health, Helsinki, Finland.

Occupational allergic contact dermatitis caused by (meth)acrylates is common in dental personnel, whereas dental acrylic fillings and crowns have rarely been reported to cause problems in dental patients. Here we report on a 48-year-old woman who developed gingivitis, stomatitis, and perioral dermatitis after a temporary crown made of restorative, two-component material had been inserted. The manufacturer stated that the temporary crown base paste and catalyst contained three (meth)acrylates, namely, a proacrylate, which is a modification of 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (BIS-GMA); a tricyclate, which is a saturated, aliphatic, tricyclic methacrylate; and urethane methacrylate. The manufacturer refused to give more exact information on the (meth)acrylates. Patch testing revealed that the patient was highly allergic to BIS-GMA, other epoxy diacrylates, and (meth)acrylates, as well as to the base paste and catalyst of the temporary crown. Accordingly, it was concluded that the allergic reaction was caused by BIS-GMA, or a cross-reacting (meth)acrylate, or other (meth)acrylates in the temporary crown.

PMID: 10688437, UI: 20151145

Oral lesions and symptoms related to metals used in dental restorations: a clinical, allergological, and histologic study.


1: J Am Acad Dermatol 1999 Sep;41(3 Pt 1):422-30

Koch P, Bahmer FA

Department of Dermatology, University of the Saarland, Homburg/Saar, Germany.

BACKGROUND: Allergy to mercury as a cause of oral lichenoid lesions (OLL) remains controversial. Some authors reported high frequency of sensitization to mercury and beneficial effect from removal of amalgam fillings in such patients, whereas others state that this procedure affects favorably all OLL, whether patients are sensitized to inorganic mercury or not. OBJECTIVE: Our purpose was to determine the frequency of sensitization to metal salts in 194 patients (patients with OLL partly adjacent to amalgam fillings: 19, oral lichen planus (OLP) without close contact to amalgam: 42, other oral diseases: 28, oral complaints: 46, control group: 59). We further studied the histologic changes of biopsy specimens from positive patch tests to metal salts, and investigated the effect of removal of amalgam in OLL, to clarify whether it is possible to identify patients who will benefit from this procedure. METHODS: Patch testing was performed with the German standard series, a dental prosthesis series, and a metal salt series including gold, mercury, and palladium salts as well as other salts of metals used in dental restorations. Late readings (10 and 17 days after application of the patch tests) were performed in all patients. RESULTS: Of 19 patients with OLL adjacent to amalgam fillings, 15 (78.9%) were sensitized to inorganic mercury (INM), significantly more than those with OLL not adjacent to amalgam, other oral diseases or complaints, and the control group. In 5 of 15 (33.3%) of the patients with OLL, a positive patch test to INM was observed only at D10 or D17. Amalgam was removed in 18 patients with OLL (sensitization to INM: 15), and in 11 patients with OLP (sensitization to INM: 2). After removal, the lesions of 13 of 15 of the INM-sensitized patients with OLL (86. 7%) and 2 with OLP healed or improved significantly, but this was not observed with the INM negative patients. Frequency of sensitization to gold sodium thiosulfate (GST) and palladium chloride 1% pet (PDC) was high in all groups. This was partly because readings were performed late. Lesions of 2 patients with allergic contact stomatitis caused by gold and 1 caused by palladium healed completely after removal of these restorations. Histologically, lichenoid changes were observed in 14 of 36 biopsy specimens of positive patch tests from INM (9/21), GST (2/10), and PDC (3/5) in all patient groups, mainly in persistent patch tests at D10 or D17. This was not observed in 12 biopsy specimens taken from persistent patch tests from other substances, including nickel sulfate. CONCLUSION: Our results suggest that sensitization to mercury is an important cause of OLL, whether all lesions or only a part of them are adjacent to amalgam fillings. Sensitization to GST may reflect true gold allergy and should be considered as a cause of oral diseases in some patients. Sensitization to PDC is frequent but has yet only little clinical relevance. Patch tests may be positive only at D10 or D17. This suggests the importance of additional readings of GST, PDC, and mercury salts at this time.

PMID: 10459117, UI: 99389763

Skin and mucosal reactions associated with dental materials.


: Eur J Oral Sci 1998 Apr;106(2 Pt 2):707-12

Hensten-Pettersen A

NIOM, Scandinavian Institute of Dental Materials, Haslum, Norway. niom@niom.no

The selection of dental materials for specific treatment purposes is primarily based on their physical properties. The composition of materials available indicates that there is the potential for adverse biological effects. The amounts of substances released are usually too low to cause any overt systemic toxic effects. However, many of the chemicals used in dentistry are irritating and may cause local damage. Also, in reactions mediated via the amplifying mechanisms of the immune system, small amounts may lead to clinical manifestations of allergic contact dermatitis and urticaria. A special problem in the diagnosis of adverse events occurs when intraoral exposure leads to generalized urticarial reactions. Due to a low level of suspicion, extraoral reactions are rarely associated with dental treatment modalities. Occupational dermatoses represent a serious problem, especially the development of an allergy to constituents of the resin-based filling materials and adhesives. The monomers of resin-based materials are volatile and penetrate latex and vinyl gloves easily. Allergic contact dermatitis related to resin-based materials may be occupationally disabling.


The effectiveness and side effects of 0.1% and 0.2% chlorhexidine mouthrinses: a clinical study.

AUTHORS: Ernst CP; Prockl K; Willershausen B

AUTHOR AFFILIATION: Department of Restorative Dentistry and Periodontology, Johannes Gutenberg University of Mainz, Germany.

SOURCE: Quintessence Int 1998 Jul;29(7):443-8


OBJECTIVE: The study compared two commercial chlorhexidine mouthrinses (Chlorhexamed 0.1% and Corsodyl 0.2%) for their effects on dental plaque and gingival inflammation, their side effects (eg, tooth staining and mucosal irritation), and patient acceptance. METHOD AND MATERIALS: One hundred thirty healthy volunteers were randomly distributed into two groups of 65 each. Each volunteer had gingivitis or chronic marginal periodontitis and used the rinse two times a day for 4 weeks. The sulcular bleeding index, approximal plaque index, gingival index, and a discoloration index were taken at baseline and once a week thereafter. The patients were questioned about taste disturbances, mucosal irritation, and their perception of the taste of the mouthrinse. RESULTS: In both groups, after 4 weeks, the mean sulcular bleeding index, approximal plaque index, and gingival index scores had decreased significantly. The discoloration index had increased significantly in both groups. There were no statistically significant differences between the two mouthrinses in any of these measurements. There were no significant differences in side effects reported by the two groups. CONCLUSION: The increase in concentration of chlorhexidine provided no clinical advantages or disadvantages.

A study of dental staining among competitive swimmers.

AUTHORS: Escartin JL; Arnedo A; Pinto V; Vela MJ

AUTHOR AFFILIATION: Dental Health Unit and Epidemiology Division, Conselleria de Sanitet, Castellon, Spain. prtextos@sgprint.com

SOURCE: Community Dent Oral Epidemiol 2000 Feb;28(1):10-7


OBJECTIVE: To estimate the prevalence of dental stains (DS) in competitive swimmers and quantify the risk of these stains compared with sportsmen in a non-swimmers group in Castellon, Spain. METHODS: Cross-sectional and case-control designs. Between July 1996 and March 1997, 404 subjects, (171 enrolled in two clubs of competitive swimming and 233 sportsmen from two schools), were examined in order to detect and classify yellowish-brown or dark-brown stains on the facial surface of the eight incisors. Participation rates were 88.6% for swimmers, and 95.7% for sportsmen. Mean of participants' age was 12 years, range 7-22 years. Castellon has three public competition swimming pools, two of which are indoors. Two of the pools used chloride products, and the third bromine for the disinfection of water. The recommended hygiene regulations were adhered to. RESULTS: Prevalence of DS was 60.2% in swimmers and 12.9% in sportsmen (P= 0.0001). Risk factors for DS included: use of competition swimming pools, age, gender, years of competition, daily consumption of coffee, red wine, and iron supplement during the last year. Professional dental cleanliness was a protective factor. In a logistic regression analysis, the use of competition swimming pools maintained a high risk of DS, odds ratio (OR)=9.28; 95% confidence interval (CI) 5.21-16.5, adjusted by the other variables. Amongst swimmers, more than 6 h of training a week increased the risk of these stains (OR=3.51; 95% CI 1.35-9.10). CONCLUSION: The study indicated a high risk of DS in competitive swimmers.


Root substance removal by scaling and root planing.

AUTHORS: Zappa U; Smith B; Simona C; Graf H; Case D; Kim W

AUTHOR AFFILIATION: Department of Periodontology, School of Dental Medicine, University of Bern, Switzerland.

SOURCE: J Periodontol 1991 Dec;62(12):750-4


The amount of root substance removed by scaling and root planing is largely unknown. The present study evaluated in vitro the root substance loss caused by a defined number of working strokes at known forces. Forty extracted teeth with loss of connective tissue attachment into the middle third of the roots were washed and embedded in plaster, leaving one entire corono-apical tooth aspect exposed. The teeth were reproducibly repositioned in a bench-vise, where a profilometer repeatedly measured root surface levels at the same location. In a standard area of the roots a total of 40 working strokes were applied. Low forces were used in 30 teeth and high forces in 10 teeth. The forces were recorded using a piezo-electric receiver built into the upper shank of the curet. Root substance loss was measured after 5, 10, 20, and 40 working strokes. The results showed that the mean low force used per working stroke across all 40 strokes was 3.04 Newtons for the low forces, and 8.48 Newtons for the high forces. Mean cumulative loss of root substance across 40 strokes was 148.7 microns at low forces, and 343.3 microns at high forces. The mean force per stroke increased slightly across the 40 strokes, while substance removal per stroke decreased. Substance removal per stroke during strokes 1 to 5 was 6.8 microns using low forces and 20.6 microns using high forces. During strokes 21 to 40 mean removal per stroke was 2.3 microns at low forces, and 5.6 microns at high forces. These results suggest that high forces remove more root substance, and loss per stroke becomes less with increasing numbers of strokes.

The effect of working parameters on root substance removal using a piezoelectric ultrasonic scaler in vitro.

AUTHORS: Flemmig TF; Petersilka GJ; Mehl A; Hickel R; Klaiber B

AUTHOR AFFILIATION: Department of Periodontology, Julius Maximilian University, Wurzburg, Germany.

SOURCE: J Clin Periodontol 1998 Feb;25(2):158-63


This study assessed defect depth and volume resulting from root instrumentation using a piezoelectric ultrasonic scaler with a slim scaling tip in vitro. Combinations of the following working parameters were analyzed: lateral forces of 0.5 N, 1 N, and 2 N; tip angulations of 0 degrees, 45 degrees, and 90 degrees; power settings of low, medium and high; and instrumentation time of 10 s, 20 s, 40 s, and 80 s. Defects were quantified using a 3D optical laser scanner. Overall, lateral force had the greatest influence on defect volume compared to instrument power setting and tip angulation (beta-weights 0.49 +/- 0.04, 0.25 +/- 0.04, and 0.14 +/- 0.04, respectively). The effects on defect depth were highest for tip angulation followed by lateral force and instrument power setting (beta-weights 0.48 +/- 0.04, 0.34 +/- 0.04, and 0.25 +/- 0.04, respectively). Interestingly, at all power settings, the highest defect volume and depth by far were found after combining 45 degrees tip angulation with 2 N of lateral force. The efficacy of the assessed piezoelectric ultrasonic scaler may be adapted to the various clinical needs by adjusting the lateral force, tip angulation, and power setting. To prevent severe root damage it is crucial to use the assessed scaler at a tip angulation of close to 0 degrees.


Tooth resorption.

AUTHORS: Ne RF; Witherspoon DE; Gutmann JL

AUTHOR AFFILIATION: Department of Restorative Sciences, Graduate Endodontics, Texas A & M University System, Baylor College of Dentistry, Dallas 75214, USA.

SOURCE: Quintessence Int 1999 Jan;30(1):9-25


Tooth resorption is a common sequela following injuries to or irritation of the periodontal ligament and/or tooth pulp. The course of tooth resorption involves an elaborate interaction among inflammatory cells, resorbing cells, and hard tissue structures. The key cells involved in resorption are of the classic type, which include osteoblasts and odontoclasts. Types of tooth resorption include internal resorption and external resorption. There are two types of internal resorption: root canal (internal) replacement resorption and internal inflammatory resorption. External resorption can be classified into four categories by its clinical and histologic manifestations: external surface resorption, external inflammatory root resorption, replacement resorption, and ankylosis. External inflammatory root resorption can be further categorized into cervical resorption with or without a vital pulp (invasive cervical root resorption) and external apical root resorption. Other variations of resorption include combined internal and external resorption and transient apical breakdown.

Root resorption of dental and traumatic origin: classification based on etiology.


AUTHOR AFFILIATION: Department of Endodontics, School of Dentistry, University of North Carolina at Chapel Hill 27599, USA.

SOURCE: Pract Periodontics Aesthet Dent 1998 May;10(4):515-22


While root resorption is a relatively common complication of dental trauma, classifications of root resorption are inconsistent and confusing. All pathological root resorption of dental origin is inflammatory in nature. For root resorption to occur, the protective superficial layer must be (internally or externally) damaged or changed and an inflammatory stimulator must be present. This article attempts to classify root resorption on the basis of etiology, i.e., the cause of the protective layer loss and the cause of the inflammatory response, to facilitate more efficient treatment.

Supragingival calculus formation in a group of young adults.


SOURCE: Quintessence Int 1996 Dec;27(12):817-20


The presence of calculus was assessed on the lingual surfaces of the mandibular anterior teeth in a randomly selected group of 63 young adults. The rate of regrowth of calculus after professional prophylaxis was also observed. Twenty-two individuals had supragingival calculus on the mandibular lingual surfaces of their teeth at baseline. Eleven of these individuals demonstrated regrowth of calculus by the end of the study, in spite of repeated professional prophylaxis. Thus, 17.5% of subjects exhibited rapid regrowth of calculus on the mandibular lingual surfaces of their teeth within 2 weeks of professional prophylaxis.

Dental calculus: recent insights into occurrence, formation, prevention, removal and oral health effects of supragingival and subgingival deposits.


AUTHOR AFFILIATION: The Procter and Gamble Company, Health Care Research Center, Mason, OH 45040-9462, USA.

SOURCE: Eur J Oral Sci 1997 Oct;105(5 Pt 2):508-22


Dental calculus, both supra- and subgingival occurs in the majority of adults worldwide. Dental calculus is calcified dental plaque, composed primarily of calcium phosphate mineral salts deposited between and within remnants of formerly viable microorganisms. A viable dental plaque covers mineralized calculus deposits. Levels of calculus and location of formation are population specific and are affected by oral hygiene habits, access to professional care, diet, age, ethnic origin, time since last dental cleaning, systemic disease and the use of prescription medications. In populations that practice regular oral hygiene and with access to regular professional care, supragingival dental calculus formation is restricted to tooth surfaces adjacent to the salivary ducts. Levels of supragingival calculus in these populations is minor and the calculus has little if any impact on oral-health. Subgingival calculus formation in these populations occurs coincident with periodontal disease (although the calculus itself appears to have little impact on attachment loss), the latter being correlated with dental plaque. In populations that do not practice regular hygiene and that do not have access to professional care, supragingival calculus occurs throughout the dentition and the extent of calculus formation can be extreme. In these populations, supragingival calculus is associated with the promotion of gingival recession. Subgingival calculus, in "low hygiene" populations, is extensive and is directly correlated with enhanced periodontal attachment loss. Despite extensive research, a complete understanding of the etiologic significance of subgingival calculus to periodontal disease remains elusive, due to inability to clearly differentiate effects of calculus versus "plaque on calculus". As a result, we are not entirely sure whether subgingival calculus is the cause or result of periodontal inflammation. Research suggests that subgingival calculus, at a minimum, may expand the radius of plaque induced periodontal injury. Removal of subgingival plaque and calculus remains the cornerstone of periodontal therapy. Calculus formation is the result of petrification of dental plaque biofilm, with mineral ions provided by bathing saliva or crevicular fluids. Supragingival calculus formation can be controlled by chemical mineralization inhibitors, applied in toothpastes or mouthrinses. These agents act to delay plaque calcification, keeping deposits in an amorphous non-hardened state to facilitate removal with regular hygiene. Clinical efficacy for these agents is typically assessed as the reduction in tartar area coverage on the teeth between dental cleaning. Research shows that topically applied mineralization inhibitors can also influence adhesion and hardness of calculus deposits on the tooth surface, facilitating removal. Future research in calculus may include the development of improved supragingival tartar control formulations, the development of treatments for the prevention of subgingival calculus formation, the development of improved methods for root detoxification and debridement and the development and application of sensitive diagnostic methods to assess subgingival debridement efficacy.


The hypermineralization of diseased root surfaces.

AUTHORS: Wirthlin MR; Pederson ED; Hancock EB; Lamberts BL; Leonard EP

SOURCE: J Periodontol 1979 Mar;50(3):125-7


Root surfaces which have lost their attachment due to chronic inflammatory periodontal disease present significant increases in calcium, magnesium, phosphorus, and fluoride. The clinical significance of this effect is not known in regards to wound healing, but it may be helpful in control of cervical sensitivity.

Periodontal disease: an overview for physicians.


Department of Oral Pathology, Biology and Diagnostic Sciences, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark 07103-2400, USA.

SOURCE: Mt Sinai J Med 1998 Oct-Nov;65(5-6):362-9


Periodontitis is now seen as resulting from a complex interplay of bacterial infection and host response, often modified by behavioral factors. There has been a fundamental change in the prevailing periodontal disease model of the 1960s, which suggested that the susceptibility to periodontitis increases with age, and that all individuals are susceptible to severe periodontal disease. More recent research has changed the belief in universal susceptibility to the current view that only some 5-20% of any population suffer from severe generalized periodontitis, and that only moderate disease affects a majority of adults. One major risk factor is smoking, as there is now a clear association between smoking and periodontal disease independent of oral hygiene, age, or any other risk factor. In human periodontitis, there is no simple, direct pathogen-disease link. There are three pathogens that have a strong association with progressive periodontal disease: Actinobacillus actinomycetemcomitans, spirochetes of acute necrotizing gingivitis, and Porphyromonas gingivalis. These pathogens may be the cause of continued loss of periodontal attachment in all periodontal disease classifications despite diligent periodontal therapy. This loss of attachment, or destruction of the periodontal ligament and loss of adjacent supporting bone, is seen in adult periodontitis, as well as in early-onset periodontitis, which affects young persons who otherwise appear healthy. The three forms of early-onset periodontitis are prepubertal periodontitis, localized and generalized juvenile periodontitis, and rapidly progressive periodontitis. They are distinguished from adult periodontitis by the age of onset of the disease, the rapid rate of disease progression, manifestations of defects in host response, and the composition of the subgingival microflora. Prepubertal periodontitis is associated with attachment loss around teeth of the deciduous and/or permanent dentition, and is often associated with severe congenital defects of hematological origin, and alterations in neutrophil chemotaxis function. Periodontitis may also be associated with systemic conditions such as metabolic disorders (diabetes mellitus, female hormonal alterations), drug-induced disorders, hematologic disorders/leukemia, and immune system disorders. These systemic disorders have been documented as capable of affecting the periodontium and/or treatment of periodontal disease. In order to rationally treat and prevent periodontal disease, we need to know the etiologic agents for specific patients, and the mechanism of bacterial pathogenesis in periodontitis. In systemic diseases in which the periodontal tissues are affected as well, early detection and carefully managed therapeutics with the physician and periodontist working together may prove beneficial to the patient's general health and quality of life.


Alcohol is no better than soap and water, and then, only with repeated applications.

TITLE: Alcohol-impregnated wipes as an alternative in hand hygiene.

AUTHORS: Butz AM; Laughon BE; Gullette DL; Larson EL

AUTHOR AFFILIATION: Johns Hopkins University School of Nursing, Baltimore, MD 21205.

SOURCE: Am J Infect Control 1990 Apr;18(2):70-6


The antimicrobial effectiveness of four hand-wash products for health care personnel included three liquid soaps that contained 4% chlorhexidine gluconate, 1% triclosan, or no antiseptic ingredient, respectively, and a 30% w/w ethyl alcohol-impregnated hand wipe. These products were evaluated for reduction in bacterial counts on hands after extended use of 15 handwashes per day for 5 consecutive days. The order of greatest to least log reduction among products at the end of the 5-day test period was chlorhexidine gluconate (2.01), triclosan (1.52), alcohol wipe (0.04), and control soap (0.03). Skin condition before and after handwash was assessed for each treatment group. Subjects reported less skin irritation with alcohol wipes than with the two antiseptic products. Repeated washing with alcohol wipes results in reductions in bacterial colony counts comparable with nonmedicated soap, sufficient to prevent transmission of pathogens by the hands in most situations that arise in nonacute health care settings. This evidence, in addition to increased user acceptability reported by the subjects who used alcohol wipes, suggests that alcohol wipes are an acceptable alternative to soap-and-water handwashing in nonacute health care settings. 

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