Microbial Analysis of Obturators During Maxillofacial Prosthodontic Treatment Over an 8-Year Period.

The aim of the study was to investigate the microbial colonization (by Candida species, anaerobic and facultative anaerobic bacteria) of maxillary obturators used for the restoration of maxillary defects, including during radiotherapy.Retrospective cohort study.Fifteen patients requiring a maxillary obturator prosthesis had swabs of their obturators and adjacent tissues taken at different stages of their treatment over a period of 8 years.Identification of microbial species from the swabs was carried out using randomly amplified polymorphic DNA polymerase chain reaction (RAPD PCR) analysis, checkerboard DNA-DNA hybridization, CHROMagar Candida chromogenic agar, and DNA sequencing.Candida species were detected in all patients and all patients developed mucositis and candidiasis during radiotherapy which was associated with an increase in colonization of surfaces with Candida spp., particularly C albicans. Microbial colonization increased during radiotherapy and as an obturator aged, and decreased following a reline, delivery of a new prosthesis, or antifungal treatment during radiotherapy.Microbial colonization of maxillary obturators was related to the stage of treatment, age of the obturator material, radiotherapy and antifungal medications, and antifungal treatment may be recommended if C albicans colonization of palatal tissues is greater than 105 colony-forming units per cm2 following the first week of radiotherapy.

The Role of Biofilms and Material Surface Characteristics in Microbial Adhesion to Maxillary Obturator Materials: A Literature Review.

BACKGROUND: Maxillofacial prosthetics includes restoration of maxillary defects resulting from resection of palate and nasosinus neoplasms with obturator prostheses which may be colonized by microorganisms and function as a reservoir of infection. Patients with neoplasms commonly also require radiotherapy that can result in changes in saliva quality and quantity and changes in the oral microbial flora. The altered flora, in individuals immunocompromised from cancer therapy, increases their risk of prosthesis-related infections. OBJECTIVES: In this review article, we explore microbial biofilms, their main components, mechanisms of microbial adhesion, and stages of biofilm development. We also discuss the different materials that are used for manufacturing maxillary obturators, their characteristic features, and how these can affect microbial adhesion. Furthermore, we shed some light on the factors that affect microbial adhesion to the surface of maxillary obturators including tissue proteins, protein adsorption, and the acquired enamel pellicle. CONCLUSIONS: The conclusions drawn from this literature review are that it is imperative to minimize the risk of local and systemic infections in immunocompromised patients with cancer having maxillary defects. It is also important to determine the role of saliva in microbial adhesion to obturator materials as well as develop materials that have a longer life span with surface characteristics that promote less microbial adhesion than current materials.

Curriculum development in final year dentistry to enhance competency and professionalism for contemporary general dental practice.

INTRODUCTION: General dentistry is the most common area of practice, and new dentists must have the competency and skills to safely deliver patient care. In New Zealand (NZ), completion of a 5-year Bachelor of Dental Surgery (BDS) degree enables graduates to register with the Dental Council in NZ. This necessitates that the clinical component of the curriculum in final year dentistry (BDS5) transparently delivers learning opportunities and evaluates competency for independent practice. A review of the BDS5 Clinical Practice course was undertaken in 2015 and a revised curriculum introduced in 2016. CURRICULUM: We present a BDS5 curriculum for a Clinical Practice course that is learner focused with emphasis on comprehensive patient-centred care, competency and professional practice. Learning opportunities and assessment processes are described alongside teacher training. These changes have provided students scaffolding to support clinical and professional development, and accommodate different learning preferences. The outcomes align with the competency requirements of the NZ regulatory body for registration as a general dental practitioner. Since its introduction 3 years ago, ongoing feedback from students and staff has been positive and indicates the curriculum is effective in achieving its objectives. CONCLUSIONS: This curriculum provides a firm foundation for students transitioning to independent clinical practice in the community and supports the professional development of clinical teachers. It may also be translated to other areas of health education to ensure the delivery of quality holistic patient care.

Resonance Frequency Analysis in Assessing Implant Stability: A Retrospective Analysis.

PURPOSE: To retrospectively assess implant stability quotient (ISQ) values in patients who were followed up between 1998 and 2014 and to evaluate any correlations between ISQ and clinical parameters, such as change in marginal bone level (MBL). MATERIALS AND METHODS: A total of 173 participants (65 men and 108 women; age range 21 to 85 years) and 383 implants were included. Implant location, MBL, and ISQ were recorded at surgery and at various recall times for statistical analysis. Mixed-model analysis was applied to evaluate the impact of clinical and demographic variables (time, implant location, patient gender) on ISQ and the correlation between ISQ and MBL. The level of significance was set at P < .05. RESULTS: Of the 21 failed implants, 20 failed within 1 year of functional loading, resulting in a 10-year cumulative implant survival estimate of 95%. The failed implants had lower ISQs at surgery (52.3 ± 7.03) and baseline (52.5 ± 4.20) when compared to surviving implants (63.0 ± 10.74 at surgery and 62.3 ± 8.30 at baseline), and the difference was statistically significant at surgery (P < .05). The mean ISQs generally increased over time, but there were various patterns of changes between implants when grouped according to patient gender and implant location. There was no statistically significant correlation between the changes in ISQ and MBL (P = .211), despite an inverse relationship. CONCLUSION: Low initial ISQ values may help to identify implants at higher risk of failure. There may be various patterns of change over time in addition to an overall increase in ISQ values. Both similar and contradictory findings were found when compared to earlier literature, and a correlation between resonance frequency analysis and MBL change could not be identified. Despite limitations, the present study provides an overview of the clinical performance of RFA based on long-term clinical data.

The periodontal restorative interface: esthetic considerations.

Esthetic considerations are a significant contributing factor in the management of prosthodontic cases and an interdisciplinary approach is often necessary to achieve an optimal result. The visible soft-tissue architecture plays a key role in developing an esthetic smile. Furthermore, an understanding of the relationship between the restorative margin and the gingiva is important for long-term stability of the result. The gingival architecture and gingival health are important for ensuring optimal esthetics following prosthodontic work and close attention to both soft and hard tissues around the teeth, before, during and after restorative procedures, will greatly improve the likelihood of a successful outcome. Moreover, knowing the options available in periodontal plastic surgery is important in esthetic dentistry today. The relevant literature related to restorative and surgical procedures when performing esthetic dentistry are reviewed in this article, and different approaches are illustrated with appropriate cases to explain the treatment approach that was utilized to improve the esthetic appearance of the case.

Interdisciplinary periodontics: the multidisciplinary approach to the planning and treatment of complex cases.

Periodontics cannot be practiced in isolation as frequently many patients have multiple dental needs or medical health issues requiring management. In addition, pathology may manifest in the periodontal tissues, and the onset and progression of periodontitis can be affected by systemic conditions, such as diabetes, and vice versa. The focus of this volume of Periodontology 2000 is interdisciplinary periodontics, and the articles included discuss the interactions and the interrelationshipbetween periodontal tissues/periodontal diseases and endodontics, fixed prosthodontics, implant dentistry, esthetics, gerodontology, radiology, orthodontics, pediatric dentistry, oral and maxillofacial surgery, oral pathology, special needs dentistry and general medicine. Previous volumes of Periodontology 2000 have covered some of the interactions between periodontal diseases and other dental disciplines, especially implant dentistry, 'and the interaction between periodontal disease and systemic disease', but there has not been a volume on interdisciplinary periodontics. The intention therefore is to show how and why periodontics should be interdisciplinary, as well as the benefits of an interdisciplinary approach; in addition, the potential consequences of using a discipline in isolation are discussed.

Measuring the attitudes of dental students towards social accountability following dental education - Qualitative findings.

BACKGROUND: The term social accountability has gained increased interest in medical education, but is relatively unexplored in dentistry. AIMS: The aim of this study is to explore dental students' attitudes towards social accountability. METHODS: A qualitative study utilizing focus groups with University of Otago final year (5th year) Bachelor of Dental Surgery (BDS) students was carried out. A questionnaire designed to measure medical students' attitudes towards social responsibility was used as a guide. Following data collection, framework analysis was used to analyze each of the three focus groups, and repeating themes were noted. RESULTS: Analysis of the focus groups discovered recurring themes, such that participants believed that dentists should be accountable to society in a professional context and that they are responsible for patients who present at their clinic but that there is no professional obligation to help reduce oral health inequalities by working with populations facing inequalities. There was strong agreement that there needs to be change to the dental health care system from a structural and political level to address oral health inequalities, rather than individual dentists assuming greater responsibility. CONCLUSION: Our findings show that dental education may not be accountable to society in the sense that it is not producing graduates who believe that they have an obligation to address the priority oral health concerns of society.

Monitoring Shore A hardness of silicone facial elastomers: the effect of natural aging and silicone type after 1 year.

OBJECTIVES: The purpose of this study was to investigate the effect of natural aging after storage in the dark for 1 year and material type on Shore A hardness of 2 silicone prosthetic elastomers. MATERIALS AND METHODS: The silicone elastomers tested were low- and high-temperature vulcanizing materials, namely, Premium and Silasto 30, respectively. Ten samples, 25 × 25 × 10 mm3, from each silicone were made and stored in sealed glass containers in the dark. Shore A hardness was measured according to the American Society for Testing Materials specification D2240. Three recordings were made on each sample at baseline and then weekly for 12 months (quadruplicate per mo). Data were analyzed by general linear modeling for repeated measures and Student-Newman-Keuls test for post hoc comparisons at α = 0.05. RESULTS: General linear modeling analysis indicated a significant influence of either silicone type (F = 229.5, P = 0.0001) or natural aging (F = 105.9, P = 0.0001) or their interaction (F = 27.6, P = 0.0001) on Shore A hardness values. For Premium and Silasto 30, Shore A hardness ranged from 16.9 to 26.0 and 32.0 to 36.3, respectively. The elastomers showed a trend to increase hardness over natural aging, which was significant (Premium) or not (Silasto 30), depending on the material and time intervals. CONCLUSIONS: Premium silicone showed a significant hardness increase after 1 year of natural aging in the dark, reaching a convergent value approximately 6 months from the onset, whereas Silasto 30 hardness remained stable during this period. Both elastomers showed Shore A hardness values within clinical acceptable limits after aging.

New Zealand dentists' use of gingival retraction techniques for fixed prosthodontics and implants.

OBJECTIVE: To identify the techniques most commonly used in New Zealand for gingival retraction for impressions of natural teeth and implants in fixed prosthodontics. DESIGN: Postal survey of a random sample of dentists METHODS: A questionnaire was mailed to all members of the New Zealand Dental Association (NZDA). Data were analysed using SPSS. RESULTS: The response rate was 51%. Veneer, crown and bridge treatments were routinely carried out by 89% of respondents, while implant treatment and/or implant-supported prostheses were provided by 65%. Around natural teeth, gingival retraction was mainly achieved with surgery (including electrosurgery, laser and rotary curettage) and/ or cord, by 82% of dentists. Cord with chemicals was used by 63% and plain cord by 37%. Gingival retraction around implants was used by 18%. Among the latter, the most popular gingival retraction method for use around implants was plain cord (used by 31%), while 25% used cord with chemicals. Another 23% reported using surgery as their means of gingival retraction around implants, while 19% reported using Expasyl (Pierre-Roland), and 2% reported using Magic Foam Cord (Dentsply), both of which are injectable matrices for gingival retraction. CONCLUSION: Dentists in New Zealand undertake a considerable amount of fixed prosthodontic and implant work. Gingival retraction around natural teeth is used commonly, while only a small number of participants report using it for implants. A surprising finding was the relatively high number of participants who reported using surgery for gingival retraction around natural teeth.

Adhesion of yeast and bacteria to oral surfaces.

Colonization of surfaces in the human body by microorganisms is an early, essential, step in the initiation of infectious disease. We have developed in vitro assays to investigate interactions between yeast or bacterial cells and human tissues, fluids, or prostheses. Such assays can be used to identify the adhesins, ligands, and receptors involved in these interactions, for example by determining which components of the microbe or human tissue/fluid interfere with adherence in the assay. The assays can also be applied to finding ways of preventing adhesion, and subsequent disease, by investigating the effects of different conditions and added compounds on adherence in the in vitro assays. We describe six assays for measuring adhesion of the oral yeast Candida albicans, a common commensal and opportunistic pathogen, or the bacterium Staphylococcus epidermidis, which is not normally pathogenic but is known to form biofilms on medical prostheses. The assays described represent two approaches to investigating adhesion; retention at a fixed time point following liquid washes; and retention against a continuous flow of medium.