Journal of the Canadian Dental Association最新文献

Objectives: Oral hairy leukoplakia (OHL) is caused by Epstein-Barr virus (EBV) and is often associated with HIV and other immunosuppressive conditions. It is rare in HIV-negative patients, but has been reported in patients who use immune-modulating medications (e.g., cyclosporine). The objectives of this study were to determine the occurrence of OHL in HIV-negative patients and report Langerhans cell counts in these lesions.

Study design: A series of 7 new cases of OHL among HIV-negative patients is described. Langerhans cells were counted using an immunoperoxidase stain for CD1a and light microscopy.

Results: The 7 patients were male, ranging in age from 26 to 69 years. Clinically, all lesions were diagnosed as leukoplakia on the lateral border of the tongue. Microscopic examination revealed hyperparakeratosis and candidiasis in some cases, acanthosis and a band-like zone with clearing of cells in the upper spinous layer, which were EBV-positive by in-situ hybridization. There was a significant decrease in Langerhans cell counts in OHL patients.

Conclusion: OHL can occur in HIV-negative patients.

Purpose: The hydrophilicity of some elastomeric impression materials has not been fully established. The purpose of this study was to measure and compare the advancing contact angle of water on the surface of several set elastomeric impression materials.

Materials and methods: We tested various consistencies of vinyl polysiloxane (VPS; Imprint 4) and vinyl polyether silicone (VPES; EXA'lence) with a polyether (PE; Impregum Soft) control. Impression discs (25.07 mm) were made using a metal die and ring. Deionized ultra-filtered water was placed on each disc and contact-angle measurements were made at 0, 15, 30, 45 and 60 s using a video contact angle drop shape analysis machine. The data were analyzed using repeated ANOVA and a post-hoc test with Bonferroni correction.

Results: VPS contact angles reached a mean of 10.1° ± 0.2° at 60 s vs. 40.7° ± 0.1° for VPES. Overall, VPS contact angles were smaller than those for VPES at all measured times. However, heavy and super quick heavy VPS had much higher contact angles at 0 s compared with other VPS consistencies. There was a significant difference in contact angles between VPS and VPES (mean difference 33.9°, p < 0.05) and between VPS and PE (mean difference 32.8°, p < 0.05) but not between VPES and PE (P = 0.196). VPS heavy and super quick heavy were significantly different from other VPS materials (p < 0.05), but not from each other (p = 1.00).

Conclusions: Set VPS is more hydrophilic than VPES. Contact-angle values of VPS indicated super hydrophilicity. VPES was hydrophilic, with measurements similar to the PE control. Thus, VPS impression materials may be excellent in terms of spreading and copying wet surfaces.

Objectives: To explore the psychosocial impacts of dentistry as described by patients.

Methods: I conducted 6 qualitative interviews with people whose access to dental care had been limited because of financial barriers, but who had recently undergone significant treatment through a dental outreach program.

Results: In addition to physical benefits (including improved sleep and diet), participants discussed how dental treatment led to a greater level of confidence and an improved self-concept. They provided powerful examples of how this confidence boost improved their social interactions and relationships. They also felt more confident about their employability.

Conclusion: The benefits of adequate dental care extend well beyond its physical and medical aspects. Dental health is connected inextricably with people's sense of self and social functioning. The far-reaching consequences of dentistry explored in this research raise questions about the inequalities in Canada's current system and the need to address them.

Objective: The aim of this study was to evaluate the accuracy of 3 thermosensitive microsensors that record "wear time" of removable oral appliances (OAs).

Methods: For in vitro testing, TheraMon (sensor T, n = 20), AIR-AID SLEEP (sensor A, n = 30) and DentiTrac (sensor D, n = 16) microsensors were placed in a water bath to simulate long and short durations of wear. Their accuracy was also assessed when they were embedded in 3 materials: acrylic, polyvinylchloride and thermoactive acrylic. In vivo testing included 14 volunteers, who wore maxillary retainers embedded with sensors A and D for 30 nights. Logs of appliance use were compared with readouts from the sensors.

Results: In the in vitro long duration of wear assessment, sensor A, with a mean absolute response difference (MARD) of 1.67 min. (SD 1.41), was significantly more accurate than sensor T (MARD 3.53 min., SD 9.80) and sensor D (MARD 4.48 min., SD 8.46). For short duration of wear, sensor A (MARD 1.41 min., SD 3.60) and sensor T (MARD 1.68 min., SD 7.64) were equal in accuracy and significantly better than sensor D (MARD 14.07 min., SD 10.20). The embedding material had no effect on the recording accuracies of the microsensors. In vivo, there was no significant difference between sensors A and D.

Conclusion: All 3 microsensors are highly accurate and reliable and can be used to record wear time of a removable OAs fabricated from various materials.

Oral appliances (OAs) are frequently used in orthodontics and for the treatment of obstructive sleep apnea. Because OAs can be inserted and removed by patients themselves, the patient's cooperation is a major component of effective treatment. In this review, we provide an overview of factors studied in the past that affect adherence to OA use in orthodontics and dental sleep medicine. We also describe future directions in adherence and the use of objective microsensor technology to measure adherence in these patients. Because removable oral appliances (OAs) can be inserted and removed by patients themselves, their cooperation and adherence to therapy are necessary to achieve success.1,2 Removable OAs, such as headgear, removable retainers and functional appliances, are used in orthodontics to correct malocclusions. In the field of sleep medicine, removable OAs are increasingly used as an option in the treatment of patients with obstructive sleep apnea (OSA).

The use of resin composites and adhesives in dental restorations is ubiquitous. However, the longevity of resin composites is less than that of comparable restorative materials, mainly because of higher fracture rates and greater prevalence of secondary caries. Dental resin composites and adhesives contain ester links, which are vulnerable to biochemical hydrolysis by esterase activity from human saliva and bacteria. In this article, we review biodegradation processes that occur in the oral cavity and their contribution to the premature failure of resin composites. Biodegradation causes deterioration of resin composite bulk and the composite-tooth interface and releases by-products, such as methacrylic acid, triethylene glycol and bishydroxy-propoxy-phenyl-propane. These by-products have been shown to affect cariogenic bacterial growth and virulence. A compromised restoration-tooth interface allows saliva and oral bacteria to infiltrate the spaces between the tooth and the composite, exacerbating the effects of biodegradation, undermining the restoration and leading to recurrent caries, hypersensitivity and pulpal inflammation. It is important to consider the biochemical stability of these materials to advance their chemistry beyond the current formulations and conceive more biochemically stable and better-performing dental resin composites and adhesives.

We examine the perspectives of 14 key informants with extensive knowledge of dental care provision in Canada regarding systemic factors that could push Canadians to participate in dental tourism. Drawing on interview discussions about Canadians' access to dental care and their participation in dental tourism, we identify systemic factors related to how dental care is financed and delivered, rising costs of dental care and consumerism in terms of their potential role in Canadians' decisions to purchase dental care abroad. Further research on individual experiences accessing and using dental care, both in Canada and abroad, could help provide a better understanding of how these factors are informing Canadians' decision-making regarding dental care and, as a result, access to needed care.

Traditionally, periodontal hand instruments are honed or sharpened during patient care as they dull easily during contact with enamel, calculus and cementum. This approach is taught in dental and hygiene schools around the world and remains the standard of care. Recently, some professional organizations have questioned whether this practice should be abandoned because of safety issues. Questions have been raised whether sharpening stones can be properly sterilized and whether the sharpening of contaminated instruments poses a health hazard for the provider. Using bacteria culture techniques and scanning electron microscopy, we tested whether contaminated ceramic sharpening stones can be sterilized. Our results demonstrate that the stones were sterile after being subjected to the manufacturer's sterilization protocol. In addition, over the last year, no incidents related to periodontal instrument sharpening have been reported among nearly 400 students at the faculty of dentistry, University of British Columbia, where chair-side sharpening is taught. Therefore, we conclude that ceramic sharpening stones can be sterilized using normal office protocols and that chair-side sharpening adds little risk beyond routine handling of operatory or periodontal instruments during patient care when proper protocols are followed.

Aim: To assess the prescribing decisions of general dentists in Vancouver and endodontists in British Columbia regarding analgesics and antibiotics for patients with endodontic disease. An additional aim was to determine whether gender, clinical experience or practice location have an impact on such decisions.

Methods: A 4-page survey was developed and distributed to approximately half the general dentists in Vancouver (n = 259) and all of the endodontists in British Columbia (n = 50). Basic demographic questions were followed by 7 clinical scenarios and a list of endodontic diagnoses. Participants were asked questions regarding their decisions to prescribe analgesics and antibiotics.

Results: The overall response rate was 49%: 72% of endodontists responded, compared with 45% of general dentists. A substantial proportion of clinicians prescribed opioid analgesics and antibiotics in the various clinical scenarios. The rate of prescription of opioid analgesics ranged from 4%-47% for the various scenarios; the rate of prescription of antibiotics was 5%-88%. General dentists reported prescribing opioid analgesics and antibiotics more often than endodontists. Gender, clinical experience and practice location did not seem to have an impact on the decision to prescribe opioid analgesics or antibiotics.

Conclusions: Based on the results of our survey, a significant proportion of dental professionals in British Columbia prescribe opioid analgesics and antibiotics during endodontic procedures when they are likely not required. General dentists tend to prescribe these medications more often than endodontists. We found no apparent differences in terms of gender, clinical experience or practice location. Dentists must be conscientious when prescribing these medications as over-prescription has negative consequences.