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Objectives: The question of health risks associated with dental materials, especially dental amalgam, has long been controversial and remains unresolved. For the past 10 years, people in Sweden with perceived adverse reactions to dental restorative materials have been entitled to apply to their local county council for subsidized replacement of restorative materials. The aim of the study was to investigate symptoms, perceived health changes over time and health-related quality of life (HRQoL) in this population, comprising subjects with subjective health impairment, allegedly because of dental materials. A further aim was to compare their HRQoL with that of the general population., Methods: A comprehensive questionnaire was sent to 515 people who had applied for subsidized replacement of dental restorations. The questionnaire covered general and oral symptoms, HRQoL, health ratings over time and dental restoration replacement., Results: The response rate was 54.4% (n=280). Most (83.2%) answered that they had undergone replacement of restorative materials because of impaired health, perceived to be related to dental restorative materials. The most common symptoms were musculoskeletal pain (67.5%), sleep disturbance (60.0%) and fatigue (58.6%). The HRQoL of the study subjects was significantly lower than that of the Swedish population in general., Conclusions: Subjects who had undergone subsidized dental restoration replacement reported persistent subjective symptoms and low HRQoL. The results indicate that replacement of restorative materials alone is insufficient to achieve improved health in patients with symptoms allegedly attributable to dental restorations., (© 2012 John Wiley & Sons A/S.)

Unlabelled: Provision of partial and complete dentures constructed from resin is commonplace and a satisfactory outcome requires the consideration of the properties of the resin, the oral tissues and prosthodontic principles. This second of a two-part series examines the advantages and disadvantages of flexible nylon denture base resins, which have found popularity for the provision of partial dentures. Adverse effects of denture base resins are examined and the benefits and shortcomings of softliners are explored. Chairside adjustment and polishing, and denture hygiene are also discussed., Clinical Relevance: Knowledge of contemporary denture base resin systems will help to achieve optimal outcomes in removable prosthodontics.

Purpose: To investigate the relationship between the type and material of dental restorations and periodontal health in a sample of Jordanians., Materials and Methods: Patients attending the Dental Teaching Clinics of Jordan University of Science and Technology with restored teeth were examined. For every patient, the plaque index, gingival index, probing depth and clinical attachment level were recorded on restored and non-restored tooth surfaces. The restoration types were Classes II, III and V, in addition to crowns and bridge abutments. The restorative materials included amalgam, tooth-coloured materials (resin composite and glass ionomer), non-precious alloys, porcelain and acrylic., Results: Class III restorations were associated with the lowest plaque index (0.62), gingival index (1.13), probing depth (1.62 mm) and clinical attachment level (0.31 mm). Class II restorations had the highest plaque index (0.99) and probing depth values (2.27 mm). Crowns and bridge abutments had the highest gingival index (1.65 and 1.61, respectively), high probing depth (2.01 and 2.15 mm), but a low plaque index (0.69 and 0.66). Class V restorations demonstrated the highest attachment loss (0.92 mm). Resin composite and glass ionomer restorative materials demonstrated the lowest gingival index (1.21) and probing depth (1.75 mm), whereas porcelain demonstrated the lowest plaque index (0.51) and clinical attachment level (0.14 mm). Amalgam was associated with the highest plaque index (1.01) and probing depth (2.29 mm). Non-precious alloys and acrylic covered castings demonstrated the highest gingival index (1.73 and 1.72, respectively) and clinical attachment level (1.00 and 0.88 mm)., Conclusions: Crowns, bridge abutments (especially acrylic and non-precious metals) and Class II amalgam restorations appear to be associated with periodontal breakdown.

Aim: The aim of this study was to investigate in vivo the influence of aged, resin-bonded, ceramic restorations on approximal dental biofilm formation and gingival inflammatory response, associated with and without customary oral hygiene., Material and Methods: In a cross-sectional and in a 10-day experimental gingivitis study, Quigley-Hein plaque index, gingival index (GI), crevicular fluid and its levels of interleukin (IL)-1alpha, -1beta and receptor antagonist were measured at appoximal surfaces of leucite-reinforced bonded ceramic coverages, resin composite restorations and enamel and compared intra-individually in 17 participants., Results: No differences were found between the ceramic, composite and enamel regarding plaque index, GI, levels of IL-1alpha, -1beta and the receptor antagonist. Throughout, higher crevicular fluid amounts were observed at ceramic sites compared with the enamel (p<0.05). In the experimental gingivitis, plaque index, GI, crevicular fluid and its IL-1alpha levels increased significantly., Conclusion: The need for optimal oral hygiene and professional preventive oral health care does not seem to be reduced with regard to approximal surfaces of aged, resin-bonded, leucite-reinforced ceramic restorations in comparison with those of a hybrid, resin composite and enamel.

Light-cured resin composites are a viable option for restoring Class I and Class II cavities; however, several researchers have reported postoperative sensitivity in such restorations. In this in vivo study, 80 teeth with Class I and Class II cavities were selected. They were divided into four groups of 20 teeth each, to be restored with composite resin using different treatment protocols. Postoperative sensitivity to cold water at various temperatures was assessed for up to three months. The data was interpreted using Chi Square Test for homogeneity among the groups, and Z values of significance for pair-wise evaluation were determined. It was found that use of self-etching primers as bonding agents underneath the composite resin restorations were associated with significantly decreased incidence of postoperative sensitivity to cold stimuli.

Resin-based restorative materials are considered safe for the vast majority of dental patients. Although constituent chemicals such as monomers, accelerators and initiators can potentially leach out of cured resin-based materials after placement, adverse reactions to these chemicals are rare and reaction symptoms commonly subside after removal of the materials. Dentists should be aware of the rare possibility that patients could have adverse reactions to constituents of resin-based materials and be vigilant in observing any adverse reactions after restoration placement. Dentists should also be cognisant of patient complaints about adverse reactions that may result from components of resin-based materials. To minimise monomer leaching and any potential risk of dermatological reactions, resin-based materials should be adequately cured. Dental health care workers should avoid direct skin contact with uncured resin-based materials. Latex and vinyl gloves do not provide adequate barrier protection to the monomers in resin-based materials.

Objective: Dental treatment involves the use of a wide range of materials. Many of the dental materials or their components pose a potential risk to the patient and member of the dental team. Pre-market biocompatibility testing cannot guarantee absolute safety, making monitoring of materials likely to cause an adverse reaction essential. The prevalence of adverse reactions to dental materials amongst dental patients and staff has not been systematically monitored in the UK. This project aims to develop a systematic approach to the evaluation and monitoring of the extent and severity of adverse reactions to dental materials in the UK., Method: Through the distribution of reporting forms to dental surgeries and laboratories in the UK, the ARRP has received 1,075 complete reports relating to adverse reactions seen or experienced by dental staff and patients., Results: The main findings were that different materials cause adverse reactions to different groups of people. The largest proportion of patient related adverse reactions were reported to be due to metals (n = 175). These were mainly amalgam associated oral lichenoid reactions (n = 124). Dental technicians reported acrylic resin as the causal factor of hand dermatitis in 61% (44 out of a total 72) of cases reported. Finally, dental surgery staff reported gloves as causing hand dermatitis in 75% of cases (398 out of a total 531)., Conclusions: Different dental materials affect different person groups depending on their exposure to the material. Dental staff are most at risk from an adverse reaction to latex gloves, whereas most reported reactions for patients were due to metals. For dental technicians the biggest danger of an adverse reaction was from acrylic resins. There is a need to continue to raise the awareness among dental professionals of the existence of the Adverse Reactions Reporting Project so as to overcome problems of under-reporting.

The purpose of the present investigation was to assess the reasons for changes in occupational health problems and patient reactions to orthodontic treatment after a survey carried out in 1987. Questionnaire data on occupation-related health complaints and patient reactions over the preceding 2 years were obtained from 121 of 170 Norwegian orthodontists (71 per cent). Most health complaints were dermatoses of the hands and fingers related to the processing of acrylic removable appliances, to composite bonding materials, or gloves. A few reactions were of a respiratory or systemic nature. In total, occupation-related dermatoses were reported by 17.4 per cent (21/121) compared with 40 per cent previously. Non-dermal complaints comprised 9 per cent compared with 18.2 per cent in 1987. Patient reactions were distributed equally between intra-oral reactions affecting lips, gingiva, oral mucosa, and tongue, and dermal reactions affecting the corner of the mouth, the dorsal part of the neck, the peri-oral area, cheeks, chin or skin elsewhere. A few patients had systemic reactions. The assumed eliciting agents of intra-oral reactions were fixed metallic appliances, acrylic removable appliances, polymer brackets or composite bonding materials, or were related to elastics. Extra-oral (dermal) reactions were attributed to metallic, elastic or textile parts of the extra-oral appliances. Some reactions were verified as allergies. The percentage of patient reactions in total was estimated to be 0.3-0.4 per cent compared with 0.8-0.9 per cent in 1987. The reduction in occupation-related health complaints among orthodontists was explained by changes in previously important hygiene factors such as soaps, detergents, etc., whereas the biomaterials-related reactions persisted. The reduction in the 2 year incidence of patient reactions was associated with a marked reduction in extra-oral reactions following preventive measures such as coating metallic devices, whereas the intra-oral reactions persisted at the same level as previously.

The histamine-releasing activity of acrylic plastics (ftorax, stomacryl, ethacryl) used for denture making and maxillofacial prostheses was studied by automated and computer-aided fiber glass method for evaluating histamine release from whole blood basophils. The results indicate that some plastics made by the thermo-polymerization method (for example, ethacryl) are characterized by higher histamine-releasing activity than the plastics made by polymerization using superhigh frequency electromagnetic energy. The method is recommended for preliminary screening of new polymers intended for dentistry and for individual selection of materials with consideration for their safety and strength characteristics.

A 71-year-old edentulous man developed a severely painful red mouth at sites of contact with a new denture. Patch testing showed allergy to samples of the denture material and to 2-hydroxyethyl methacrylate. Patch testing to methyl methacrylate was negative. Prolonged boiling of the denture resulted in reversal of his symptoms and samples of this fully cured denture material produced negative patch tests. While allergy to acrylates is a rare cause of stomatitis, this possibility must be considered in patients presenting with oral symptoms. Material safety data sheets are unreliable in providing information regarding the type of acrylate present in the material. Hence, patch testing should be performed with a battery of acrylate allergens as well as with small samples of the denture material.

The acrylic content of dental composites poses a risk of adverse reactions. Although the quantities of the substances released are probably too small to cause systemic reactions, local skin or mucosal reactions may arise from direct contact with dental composites. In fact, epidemiological data suggest that most known side effects of dental resins are occupational dermatoses. They may either be due to irritation or allergy. In the Scandinavian countries, occupational dermatoses are relatively common among dental staff, sometimes entailing occupational disability and re-schooling. Most of these reactions can be avoided by observing precautions such as the minimization of the oxygen-inhibited-layer (OIL) in set composites and by using the resin-paste enamel bonding technique. The risk of occupational dermatoses could be reduced by the development of new bonding techniques and careful risk-benefit assessments in the use of dental composites.

Several chemicals are capable of inducing contact leukoderma. Here we report on a dental nurse who had been investigated elsewhere at a dermatology clinic 2.8 years earlier because of suspected occupational fingertip dermatitis. She had been patch tested on her upper arm with dental acrylic resins "as is." These strong concentrations of patch test substances caused a severe allergic reaction in the upper arm, and the patch test sites have remained vitiliginous for 2.8 years. Active sensitization did not take place because the patient had been sensitized earlier as shown by the allergic 2-day readings with acrylics during the first patch test session. It is assumed that acrylates induced contact vitiligo, but the dental acrylics may have also contained other chemicals (eg, hydroquinone or phenolic substances) capable of causing vitiligo. The main point to be learned from the present results is that dental acrylics should never be patch tested "as is." We also discourage the practice of use tests, open tests, or repeated open patch tests with undiluted dental acrylics because of the risk of active sensitization from single exposure.

The acrylic content of modern dental materials poses a risk of adverse reactions. Although the quantities of the substances released are normally too small to cause systemic reactions, local reactions may occur resulting in damage to the skin. A study, in which 81 dental workers referred to dermatologists for a variety of adverse reactions were patch tested, showed work-related dermatoses to represent a serious problem for dental staff, sometimes entailing occupational disability and re-schooling. Much of this could be avoided by observing special precautions to prevent direct contact with the sensitising substances in composite materials used in dental surgery. Since the use of dental amalgam has been reduced to about 10 per cent of all fillings in Sweden, the prevalence of adverse local reactions to the acrylic composite materials which are used instead may be expected to increase.

Allergies related to dentistry generally constitute delayed hypersensitive reactions to specific dental materials. Although true allergic hypersensitivity to dental materials is rare, certain products have definite allergenic properties. Extensive reports in the literature substantiate that certain materials cause allergies in patients, who exhibit mucosal and skin symptoms. Currently, however, neither substantial data nor clinical experience unequivocally contraindicate the discontinuance of any of the materials, which include dental amalgam and nickel- and chromium-containing metals. The dentist forms a vital link in the team approach to the differential diagnosis of allergenic biomaterials that elicit symptoms in a patient, not only intraorally, but also on unrelated parts of the body.

The cytotoxicity of a range of dental restorative cements was assessed by continuous observation of cultures with inverted microscopy and by light microscopic study of fixed preparations, using an in vitro model with cultured test cells derived from human periodontal ligament. The sequential morphological changes observed over a seven day period showed different degrees of cell loss and patterns of injury in response to different restorative materials, reflecting primarily either nuclear or cytoplasmic damage. Attempts at recovery were frequently identified as the culture period was extended and were characterized by recolonization of denuded areas of the culture well. It was concluded that differing dental cements damage cells through a variety of mechanisms and that the test cells exhibit differing degrees of susceptibility to injury. Assays based on short-term cultures may overestimate cytotoxicity by not allowing for cell recovery from reversible injury or repopulation of monolayers by proliferation of resistant cells.

During a 7-year period, 56 patients were referred to the Department of General Pathology and Internal Medicine and the Department of Dental Materials, University of Amsterdam, to determine whether contact allergic reactions to dental materials were the cause of their complaints. On the first consultation with the patient a detailed history focusing on the complaints themselves, general medical history, and special clinical history of allergic skin reaction was obtained. Oral examinations were performed, and all patients were referred to the allergy clinic at the department of dermatology for skin tests. There was a strong female predominance in the referred group. Most of the patients with allergic contact stomatitis mentioned a burning sensation in the mouth. In only 16 of the 56 patients could the diagnosis of allergic contact stomatitis be established. From this study it can also be concluded that the combination of a positive allergic history and positive allergic skin reactions with or without visible oral signs are important for the diagnosis of allergic contact stomatitis.

Both self-cured and UV-cured resin-base dental materials are used in preventive, restorative, and orthodontic dentistry. Polymerization is initiated in both systems by free radicals. Self-curing materials generate free radicals by means of chemical compounds included in their formulation. UV-curing systems rely upon externally-supplied, long wavelength, ultraviolet radiation to produce free radicals within the material. Therefore, although the major chemical components of both systems are similar in many respects, each system has particular advantages and disadvantages over the other, which must be recognized by the practitioner. Substantial differences exist, for example, in the color stability of these two types of materials, because of the fact that the UV-cured system cannot include UV absorbers, which protect the self-cured systems from discoloration after exposure to sunlight. UV-cured systems require a limitation on the maximum depth of filled restorative that can be cured at one time, since the filler particles attenuate UV radiation. The limit-layer is generally established as 1-1-5 mm maximum thickness. Therefore, UV-cured filled systems are more time-consuming in restorations of deeper cavities. This liability is also in evidence as it affects the degree of polymerization of UV-cured filled systems. The uncertainty of complete polymerization is apparently responsible for highly erratic compressive strength data found with UV-cured restoratives. Normally, the amount of unpolymerized monomer is much less predictable in UV-cured systems, over that which is obtained in self-cured materials. The presence of a larger fraction of unpolymerized monomer creates a greater potential for pulpal injury from UV-cured restorative materials. The catalyst used in several UV-cured systems is benzoin methyl ether, a compound of rather high toxicity (LD50:300 mg/kg). The safety of using UV radiation in the vicinity of oral mucosa has not been firmly established. The design of the UV lamp should provide for focusing all radiation onto hard tissue. However, UV-cured systems do offer several advantages over self-cured systems. They normally are one-component systems and therefore are more convenient to use in certain types of applications, e.g., fissure sealing. UV-cured systems also provide an unlimited working time, an important advantage for specific applications.

The spectral distributions of a range of dental photocuring sources were measured at the exit window and at a distance of 10 cm. The former enabled the evaluation of a newly proposed photocuring efficiency index which correlates well with the depth of cure of the photopolymerized resins, thus providing a basis for the comparison of different photocuring sources. The spectral irradiance of the sources obeyed the inverse-square law, allowing a comparison with the ACGIH threshold limit values. According to these criteria, no ocular hazard is posed to the patient or clinician by u.v.-A or u.v.-B radiation nor to the patient by the visible light when momentarily exposed to the sources. Similarly the ACGIH criterion indicates that the clinician does not risk chorioretinal injury provided the exposure is restricted to less than 140 s in a 3 h period.