Chris Wyatt

The effect of prosthodontic treatment on alveolar bone loss: a review of the literature.

STATEMENT OF PROBLEM Complete, fixed partial, removable partial, and implant-supported dentures have been used to comfortably and esthetically replace missing teeth. However, it is not certain what effect these prostheses have on the residual ridge. PURPOSE This article compares various prosthetic treatments to restore completely and partially edentulous mouths for their ability to preserve residual alveolar bone. MATERIAL AND METHODS A review of the literature was performed to discuss the effects of tooth replacement on residual alveolar bone. RESULTS The literature seems to indicate that the presence of a dental prosthesis affects the size and form of the residual alveolar ridge and bone. CONCLUSION An implant-supported fixed prosthesis to restore missing teeth in partially or completely edentulous jaws seems to be the best means of preserving residual alveolar bone.

Chlorhexidine and preservation of sound tooth structure in older adults. A placebo-controlled trial.

The Trial to Enhance Elderly Teeth Health (TEETH) was designed to test the impact of regular rinsing with a 0.12% chlorhexidine (CHX) solution on tooth loss, and the causes of tooth loss (caries, periodontal disease and trauma) were also investigated. This paper reports on the effectiveness of a 0.12% CHX solution for controlling caries using a tooth surface (coronal and root) survival analysis. A total of 1,101 low income elders in Seattle (United States) and Vancouver (Canada), aged 60–75 years, were recruited for a double-blind clinical trial and assigned to either a CHX (n = 550) or a placebo (n = 551) mouth rinse. Subjects alternated between daily rinsing for 1 month, followed by weekly rinsing for 5 months. All sound coronal and root surfaces at baseline were followed annually for up to 5 years. At each follow-up examination, those tooth surfaces with caries, restored, or extracted were scored as ‘carious’. The hazard ratio associated with CHX for a sound surface to become filled, decayed, or extracted was 0.87 for coronal surfaces (95% confidence interval: 0.71–1.14, p = 0.20) and 0.91 for root surfaces (95% confidence interval: 0.73–1.14, p = 0.41). These findings suggest that regular rinsing with CHX does not have a substantial effect on the preservation of sound tooth structure in older adults.

A 5-year follow-up of older adults residing in long-term care facilities: utilisation of a comprehensive dental programme

OBJECTIVE This study will compare the clinical outcomes of 139 elders residing in long-term care (LTC) who received dental treatment with those who did not receive care under a comprehensive dental programme over 5 years. BACKGROUND Numerous studies have documented very poor oral health and limited access to dental care among frail older adults residing in LTC facilities. The University of British Columbia and Providence Healthcare developed a comprehensive dental programme to serve elderly LTC residents within seven Vancouver hospitals. Since 2002, the Geriatric Dentistry Programme has provided annual oral health assessments and access to comprehensive dental care. MATERIAL AND METHODS A comprehensive oral health assessment was provided using CODE (an index of Clinical Oral Disorders in Elders). A change in oral health status (improvement or worsening) was evaluated by measuring CODE scores including caries and periodontal condition, and other aspects of the dentition. RESULTS Eighty-three residents received dental treatment of some form over the 5 years, while 56 did not receive any treatment beyond an annual examination. The percentage of residents initially recommended for treatment in 2002 was 97%, which declined to 70-73% after the 3rd year. The percentage of residents treated increased after the first year and remained at 56-72% thereafter. The comparison between CODE scores from baseline and 5 years later showed an improvement for those receiving care (p = 0.02, chi(2) = 7.9, df = 2). CONCLUSION Within the limitations of this study, residents who did consent and receive care showed an improvement in their oral health status after 5 years.

A comparison of physical characteristics of six hard denture reline materials

Six rigid autopolymerizing acrylic resins were examined to determine and compare the cost per reline, the curing temperatures, the setting times, and the porosity of each material. The cost per reline ranged from

Assessment of the Internal Fit of Lithium Disilicate Crowns Using Micro-CT.

0.63 to

Predictors of multiple tooth loss among socioculturally diverse elderly subjects

1.55. Three product groups had significantly different mean setting times, and two groups had significantly different mean setting temperatures. SEM cross-sections of each product revealed an apparently porous-free solid mass of acrylic resin, which in two products was overlayed by a thin porous surface layer. The physical characteristics of any one product did not indicate clinical superiority.

Action planning for daily mouth care in long-term care: the brushing up on mouth care project.

PURPOSE The aim of this study was to compare the internal fit of lithium disilicate crowns fabricated using digital technology with those fabricated by conventional means. MATERIALS AND METHODS Forty-five lithium disilicate crowns were fabricated: 15 using digital impression and computer-aided design/computer-aided machining technique (group 1), 15 from the same digital impressions, but using a conventional die and laboratory fabrication process (group 2), and 15 using a conventional poly (vinyl siloxane) (PVS) impression and laboratory fabrication process (group 3). Tooth #15 was prepared for all-ceramic restoration on an ivorine typodont, which was digitized and a replica milled in zirconia to serve as master model. The master zirconia model was used for the impression procedures. Duplicate dies of the master zirconia die were made in polyurethane, enabling the internal fit of each crown to be evaluated using X-ray microcomputed tomography. The total volume of the internal space between the crown and die, the mean and maximum thickness of this space, and the percentage of the space that was at or below 120 μm thickness was calculated for each group and statistically tested for significant difference using one-way ANOVA, with post hoc Scheffé analysis. RESULTS Group 1 crowns resulted in a smaller volume of internal space (12.49 ± 1.50 mm(3)) compared to group 2 (15.40 ± 2.59 mm(3) ) and to those of group 3 (18.01 ± 2.44 mm(3)). The mean thickness of the internal space for group 1 (0.16 ± 0.01 mm) and for group 2 (0.17 ± 0.03 mm) was significantly lower than that of group 3 (0.21 ± 0.03 mm). The average percentage of the internal space of a thickness of 120 μm and below was different between the three groups: 46.73 ± 5.66% for group 1, 37.08 ± 17.69% for group 2, and 22.89 ± 9.72% for group 3. Three-dimensional renderings of the internal space were also created. CONCLUSIONS The results of this study suggested that pressed and milled IPS e. max crowns from LAVA COS digital impressions had a better internal fit to the prepared tooth than pressed IPS e.max crowns from PVS impressions in terms of total volume of internal space, average thickness of internal space, and percentage of internal space at or below 120 μm.

Marginal Fit of Lithium Disilicate Crowns Fabricated Using Conventional and Digital Methodology: A Three-Dimensional Analysis

PURPOSE This study identifies clinical factors that predict multiple tooth loss in a socioculturally diverse population of older adults. MATERIALS AND METHODS A total of 193 participants from English-, Chinese-, or Punjabi-speaking communities in Vancouver, British Columbia, with low incomes and irregular use of dental services were followed for 5 years as part of a clinical trial of a 0.12% chlorhexidine mouthrinse. The participants were interviewed and examined clinically, including panoramic radiographs, at baseline and annually for 5 years. Binary logistic regression was used to test the hypothesis that there was no difference between incidence of multiple (≥ 3) tooth loss in older people with various biologic, behavioral, prosthodontic, and cultural variables over 5 years. RESULTS Multiple tooth loss, which was distributed similarly among the groups in the trial, occurred in 39 (20%) participants over 5 years. The use of removable prostheses was the best predictor of loss, followed by the number of carious surfaces and number of sites with gingival attachment loss > 6 mm. The pattern of prediction was consistent across the three linguocultural groups. CONCLUSION The use of removable dentures was the dominant predictor of multiple tooth loss in the three communities, but that tooth loss was not significantly associated with the cultural heritage of the participants.

Case for implant platform unswitching

Research focusing on the introduction of daily mouth care programs for dependent older adults in long-term care has met with limited success. There is a need for greater awareness about the importance of oral health, more education for those providing oral care, and organizational structures that provide policy and administrative support for daily mouth care. The purpose of this paper is to describe the establishment of an oral care action plan for long-term care using an interdisciplinary collaborative approach. Methods. Elements of a program planning cycle that includes assessment, planning, implementation, and evaluation guided this work and are described in this paper. Findings associated with assessment and planning are detailed. Assessment involved exploration of internal and external factors influencing oral care in long-term care and included document review, focus groups and one-on-one interviews with end-users. The planning phase brought care providers, stakeholders, and researchers together to design a set of actions to integrate oral care into the organizational policy and practice of the research settings. Findings. The establishment of a meaningful and productive collaboration was beneficial for developing realistic goals, understanding context and institutional culture, creating actions suitable and applicable for end-users, and laying a foundation for broader networking with relevant stakeholders and health policy makers.

The accuracy of virtual interocclusal registration during intraoral scanning

PURPOSE To compare the marginal fit of lithium disilicate (LD) crowns fabricated with digital impression and manufacturing (DD), digital impression and traditional pressed manufacturing (DP), and traditional impression and manufacturing (TP). MATERIALS AND METHODS Tooth #15 was prepared for all-ceramic crowns on an ivorine typodont. There were 45 LD crowns fabricated using three techniques: DD, DP, and TP. Microcomputed tomography (micro-CT) was used to assess the 2D and 3D marginal fit of crowns in all three groups. The 2D vertical marginal gap (MG) measurements were done at 20 systematically selected points/crown, while the 3D measurements represented the 3D volume of the gap measured circumferentially at the crown margin. Frequencies of different marginal discrepancies were also recorded, including overextension (OE), underextension (UE), and marginal chipping. Crowns with vertical MG > 120 μm at more than five points were considered unacceptable and were rejected. The results were analyzed by one-way ANOVA with Scheffe post hoc test (α = 0.05). RESULTS DD crowns demonstrated significantly smaller mean vertical MG (33.3 ± 19.99 μm) compared to DP (54.08 ± 32.34 μm) and TP (51.88 ± 35.34 μm) crowns. Similarly, MG volume was significantly lower in the DD group (3.32 ± 0.58 mm3 ) compared to TP group (4.16 ± 0.59 mm3 ). The mean MG volume for the DP group (3.55 ± 0.78 mm3 ) was not significantly different from the other groups. The occurrence of underextension error was higher in DP (6.25%) and TP (5.4%) than in DD (0.33%) group, while overextension was more frequent in DD (37.67%) than in TP (28.85%) and DP (18.75%) groups. Overall, 4 out of 45 crowns fabricated were deemed unacceptable based on the vertical MG measurements (three in TP group and one in DP group; all crowns in DD group were deemed acceptable). CONCLUSION The results suggested that digital impression and CAD/CAM technology is a suitable, better alternative to traditional impression and manufacturing.