A new method for intraoral patch testing

Adverse Drug Reactions in the Orofacial Region

A wide spectrum of drugs can sometimes give rise to numerous adverse orofacial manifestations, particularly dry mouth, taste disturbances, oral mucosal ulceration, and/or gingival swelling. There are few relevant randomized double-blind controlled studies in this field, and therefore this paper reviews the data from case reports, small series, and non-peer-reviewed reports of adverse drug reactions affecting the orofacial region (available from a MEDLINE search to April, 2003). The more common and significant adverse orofacial consequences of drug therapy are discussed.

Biocompatibility of dental casting alloys

Most cast dental restorations are made from alloys or commercially pure titanium (cpTi). Many orthodontic appliances are also fabricated from metallic materials. It has been documented in vitro and in vivo that metallic dental devices release metal ions, mainly due to corrosion. Those metallic components may be locally and systemically distributed and could play a role in the etiology of oral and systemic pathological conditions. The quality and quantity of the released cations depend upon the type of alloy and various corrosion parameters. No general correlation has been observed between alloy nobility and corrosion. However, it has been documented that some Ni-based alloys, such as beryllium-containing Ni alloys, exhibit increased corrosion, specifically at low pH. Further, microparticles are abraded from metallic restorations due to wear. In sufficient quantities, released metal ions-particularly Cu, Ni, Be, and abraded microparticles-can also induce inflammation of the adjacent periodontal tissues and the oral mucosa. While there is also some in vitro evidence that the immune response can be altered by various metal ions, the role of these ions in oral inflammatory diseases such as gingivitis and periodontitis is unknown. Allergic reactions due to metallic dental restorations have been documented. Ni has especially been identified as being highly allergenic. Interestingly, from 34% to 65.5% of the patients who are allergic to Ni are also allergic to Pd. Further, Pd allergy always occurrs with Ni sensitivity. In contrast, no study has been published which supports the hypothesis that dental metallic materials are mutagenic/genotoxic or might be a carcinogenic hazard to man. Taken together, very contradictory data have been documented regarding the local and systemic effects of dental casting alloys and metallic ions released from them. Therefore, it is of critical importance to elucidate the release of cations from metallic dental restorations in the oral environment and to determine the biological interactions of released metal components with oral and systemic tissues.

Healing of oral lichenoid lesions after replacing amalgam restorations: a systematic review

OBJECTIVE

We sought to systematically review the literature related to oral lichenoid lesions (OLLs) and amalgam restorations.

STUDY DESIGN

Cohort and case-controlled studies (no randomized controlled trials or controlled clinical trials available) were reviewed with respect to inclusion criteria and data on patients with OLLs, treatment interventions, and the measurement of outcomes.

RESULTS

Fourteen cohort and 5 case-controlled trials met the criteria. The study population consisted of 1158 patients (27% male and 73% female; age range, 23-79 years). From 16% to 91% of patients had positive patch test results for at least 1 mercury compound. Of 1158 patients, 636 had to have their restorations replaced. The follow-up period ranged from 2 months to 9 1/2 years. Complete healing ranged from 37.5% to 100%. The greatest improvements were seen in lesions in close contact with amalgam.

CONCLUSIONS

Protocols must be standardized to obtain valid results. The replacement of amalgam restorations can result in the resolution or improvement of OLLs. Patch testing seems to be of limited value. The topographic relationship between an OLL and an amalgam restoration is a useful--but not conclusive--marker.

Management of oral lichen planus

Lichen planus is a relatively common disorder of the stratified squamous epithelia. Most dental and medical practitioners see patients with lichen planus, but not all are recognized as having the disease. Patients with lichen planus may have concomitant involvement of the disease in multiple sites. Oral lichen planus lesions usually have a distinctive clinical morphology and characteristic distribution, but oral lichen planus may also present a confusing array of patterns and forms, and other disorders may clinically mimic oral lichen planus. The etiopathogenesis of lichen planus appears to be complex, with interactions between genetic, environmental, and lifestyle factors. Much has now been clarified about the etiopathogenic mechanisms involved and interesting new associations, such as with liver disease, have emerged. The management of lichen planus is still not totally satisfactory in all cases and there is as yet no definitive treatment that results in long term remission, but there have been advances in the control of the condition. Amongst the many treatments available, high potency topical corticosteroids remain the most reliably effective, though topical cyclosporine, topical tacrolimus, or systemic corticosteroids may be indicated in patients whose condition is unresponsive to topical corticosteroids.

Biocompatibility of dental casting alloys: a review

STATEMENT OF PROBLEM

Dental casting alloys are widely used in applications that place them into contact with oral tissues for many years. With the development of new dental alloys over the past 15 years, many questions remain about their biologic safety. Practitioners must choose among hundreds of alloy compositions, often without regard to biologic properties.

PURPOSE

This article is an evidence-based tutorial for clinicians. Concepts and current issues relevant to the biologic effects of dental casting alloys are presented.

SUMMARY

The single most relevant property of a casting alloy to its biologic safety is its corrosion. Systemic and local toxicity, allergy, and carcinogenicity all result from elements in the alloy being released into the mouth during corrosion. Little evidence supports concerns of casting alloys causing systemic toxicity. The occurrence of local toxic effects (adjacent to the alloy) is not well documented, but is a higher risk, primarily because local tissues are exposed to much higher concentrations of released metal ions. Several elements such as nickel and cobalt have relatively high potential to cause allergy, but the true risk of using alloys containing these elements remains undefined. Prudence dictates that alloys containing these elements be avoided if possible. Several elements in casting alloys are known mutagens, and a few such as beryllium and cadmium are known carcinogens in different chemical forms. Despite these facts, carcinogenic effects from dental casting alloys have not been demonstrated. Prudent practitioners should avoid alloys containing these known carcinogens.

CONCLUSION

To minimize biologic risks, dentists should select alloys that have the lowest release of elements (lowest corrosion). This goal can be achieved by using high-noble or noble alloys with single-phase microstructures. However, there are exceptions to this generality, and selection of an alloy should be made on a case-by-case basis using corrosion and biologic data from dental manufacturers.

Update on oral lichen planus: etiopathogenesis and management

Lichen planus (LP) is a relatively common disorder of the stratified squamous epithelia, which is, in many ways, an enigma. This paper is the consensus outcome of a workshop held in Switzerland in 1995, involving a selection of clinicians and scientists with an interest in the condition and its management. The oral (OLP) eruptions usually have a distinct clinical morphology and characteristic distribution, but OLP may also present a confusing array of patterns and forms, and other disorders may clinically simulate OLP. Lesions may affect other mucosae and/or skin. Lichen planus is probably of multifactorial origin, sometimes induced by drugs or dental materials, often idiopathic, and with an immunopathogenesis involving T-cells in particular. The etiopathogenesis appears to be complex, with interactions between and among genetic, environmental, and lifestyle factors, but much has now been clarified about the mechanisms involved, and interesting new associations, such as with liver disease, have emerged. The management of lichen planus is still not totally satisfactory, and there is as yet no definitive treatment, but there have been advances in the control of the condition. There is no curative treatment available; immunomodulation, however, can control the condition. Based on the observed increased risk of malignant development, OLP patients should be offered regular follow-up examination from two to four times annually and asked to report any changes in their lesions and/or symptoms. Follow-up may be particularly important in patients with atrophic/ulcerative/erosive affections of the tongue, the gingiva, or the buccal mucosa. Much more research is required into the genetic and environmental aspects of lichen planus, into the premalignant potential, and into the possible associations with chronic liver, and other disorders. More clinical studies are required into the possible efficacy of immunomodulatory drugs such as pentoxifylline and thalidomide.

Hg-provocation of oral mucosa in patients with oral lichenoid lesions

Five amalgam-bearing patients, with clinically and histologically confirmed oral lichenoid lesions, were tested by applying 0.5% Hg in petrolatum for 10 min to clinically normal mucosa. Control sites were exposed to petrolatum only. Four amalgam-bearing patients with no clinical evidence of oral lichenoid lesions served as controls; they were subjected to similar Hg and petrolatum exposure. After 24 h, biopsies were taken and immunocytochemically analyzed with monoclonal antibodies to lymphoid and nonlymphoid cells. No distinct differences could be detected between the Hg-exposed areas of the lichen patients and those of the nonlichen patients. Furthermore, normal mucosa exposed to petrolatum only showed a staining pattern in the lichen patients which was no different from the nonlichen patients. The findings are discussed with respect to possible mechanisms of development of lichen-like lesions in oral mucosa.

Casting alloys: side-effects

Side-effects from dental materials are a minor problem, but should be recognized. In recent questionnaire surveys about side-effects, the incidence was estimated to be 1:300 in periodontics and 1:2600 in pedodontics. None of these reactions was related to dental casting alloys. In prosthodontics, the incidence was calculated to be about 1:400, and about 27% were related to base-metal alloys for removable partial dentures (cobalt, chromium, nickel) and to noble/gold-based alloys for porcelain-fused-to-metal restorations. The complaints consisted of intra-oral reactions (such as redness, swelling, and pain of the oral mucosa and lips), oral/gingival lichenoid reactions, and a few instances of systemic reactions. In orthodontics, the incidence was 1:100, and most reactions (85%) were related to metal parts of the extra-oral anchorage devices. Even though the extensive use of base-metal alloys has been of major concern to the dental profession, relatively few case reports substantiate this concern. Allergy to gold-based dental restorations has been more commonly reported. Palladium-based alloys have been associated with several cases of stomatitis and oral lichenoid reactions. Palladium allergy seems to occur mainly in patients who are very sensitive to nickel. All casting alloys, except titanium, seem to have a potential for eliciting adverse reactions in individual hypersensitive patients. Tolerance induction may be a possible benefit of the use of intra-orally placed alloys. In non-sensitized individuals, oral antigenic contacts to nickel and chromium may induce tolerance rather than sensitization. A variety of systemic diseases and reactions has been claimed to be caused by dental materials. The claims are generally poorly documented.

T-lymphocyte and Langerhans cell distribution in normal and allergically induced oral mucosa in contact with nickel-containing dental alloys

An in vivo comparison was made between the contact allergic stomatitis-inducing capacity of nickel, nickel-containing dental alloys and a non-corrosive precious metal. Fifteen patients with a positive allergic skin reaction to nickel were divided into 3 groups (A, B and C). The patients in Group A (n = 4) were fitted with an intra-oral corrosion-resistant nickel-chromium Alloy A; the patients of Group B (n = 5) received a more corrosion prone nickel-chromium Alloy B and in Group C (n = 6) strongly corroding pure nickel was used. A corrosion-resistant foil of pure palladium was placed on the contralateral side. Reactivity of pure nickel foil was also tested on the skin in Group C. Immunohistological examination of the oral mucosa on the test and reference sides was performed with monoclonal antibodies directed against T-lymphocyte subsets and Langerhans cells (LC). The results showed that at the pure nickel site the LC did increase significantly in the connective tissue (approx. 4X) of the oral mucosa. However, statistical analysis of all 6 patients of Group C together showed no corresponding increase of LC in the epithelium at the site with the pure nickel, although a numerical increase of LC was noted in the epithelium adjacent to the pure nickel foil in 2 patients, which was remarkable. It can be concluded from statistical analysis that both the reference foils and the test foils can influence the number of suppressor/cytotoxic T-lymphocytes in the connective tissue.(ABSTRACT TRUNCATED AT 250 WORDS)