Use of handgrip strength measurement as an alternative for assessing chewing function in people with dementia

Background: Chewing ability and handgrip strength can be independent explanatory factors of physical fitness. The usability of measurement procedures for assessing chewing function in people with dementia seems to be limited. This study aimed to show an association between handgrip strength and chewing function to enable the use of handgrip strength measurement as an alternative for determining chewing parameters in people with dementia. METHODS: The data analysed here are part of the OrBiD (Oral Health, Bite Force and Dementia) pilot study. A total of 120 participants were assigned to five evaluation groups based on their cognitive abilities using the Mini-Mental State Examination (MMSE). The MMSE groups in this data analysis were "no dementia" (noDem, MMSE 28-30), "mild cognitive impairment" (mCI, MMSE 25-27), and "mild dementia" (mDem, MMSE 18-24). Handgrip strength, maximum occlusal force, and chewing efficiency were measured. RESULTS: The Mini-Mental State Examination scores among all participants (n = 71) resulted in a median of 27 and a range of 18-30. An association between maximum handgrip strength and the cognitive impairment of the participants was shown. Nevertheless, the use of handgrip strength measurement as an alternative for determining chewing function was not verified in this study. Conclusions: The feasibility and reliability of chewing function measurements in people with dementia should be investigated. Existing measurement procedures may need to be adapted or new assessments may need to be developed to be usable in people with dementia. Trial registration: ClinicalTrials.gov NCT03775772. Keywords: Bite force; Chewing efficiency; Cognitive impairment; Dementia; Handgrip strength; Measurement; Mini-Mental State Examinatio

Polyoxymethylene as Material for Removable Partial Dentures—A Literature Review and Illustrating Case Report

Compared to thermoplastic manufacturing techniques, computer-aided design (CAD) and computer-aided manufacturing (CAM) technologies make it easier to process modern restorative and prosthetic materials with improved material properties. In dentistry, tooth-colored alternatives to metal-based frameworks for application in removable dental prostheses (RDP) emerged. With regard to this aspect, the current article provides an overview of the specific material properties of polyoxymethylene (POM). Furthermore, it reviews scientific literature indexed in PubMed and Web of Science that focuses on RDPs fabricated from POM within the last 10 years. Finally, a prosthetic rehabilitation of a patient with a RDP fabricated from POM is illustrated and observations during a follow-up over 10 months are described. Scientific data and clinical observations indicate that polyoxymethylene is a promising material that bridges gaps in dental therapeutic options. While survival time may be limited due to wear, POM might be a favorable option for application in semi-permanent restorations

Tooth-Colored CAD/CAM Materials for Application in 3-Unit Fixed Dental Prostheses in the Molar Area: An Illustrated Clinical Comparison

The aim of this study was to compare the clinical properties of tooth-colored computer-aided design/computer-aided manufacturing (CAD/CAM) materials for the fabrication of a 3-unit fixed dental prostheses (FDPs) in the same clinical scenario. A 53-year-old female patient was supplied with a 3-unit FDP to replace a second premolar in the upper jaw. Restorations were fabricated from 3 mol%, 4 mol%, and 5 mol% yttrium oxide zirconia, zirconia with translucency gradient, indirect composite resin, polyetheretherketone (PEEK), and polyetherketoneketone (PEKK). Milling time, weight, and radiopacity were investigated. Esthetics were examined following the US Public Health Service criteria (USPHS). The milling time for zirconia was twice as high as for the indirect composite resin, PEEK, or PEKK. The latter materials had a weight of 2 g each, while zirconia restorations yielded 5 g. Zirconia presented intense radiopacity. PEEK and PEKK required veneering and an opaquer was applied to the PEKK framework. All FDPs showed acceptable esthetics. PEEK and PEKK restorations were featured by a grayish shimmering. A variety of CAD/CAM materials are available to fabricate 3-unit FDPs with esthetically acceptable results. In the esthetic zone, PEEK and PEKK require veneering and an opaquer might be applied. Milling time, weight, and radiopacity were relatively high for zirconia FDPs

Utilization of dental services and health literacy by older seniors during the COVID-19 pandemic

Background: This study aimed to investigate the utilization of dental services by older seniors during the COVID-19 pandemic and to evaluate their ability of finding, understanding, and using information on COVID-19. Methods: At the end of February 2021, a survey addressing demographic characteristics of the participants, (pain-associated) utilization of dental services, worries regarding a potential COVID-19 infection, the individual use of protective masks, and difficulties regarding the access to information on COVID-19 (by using the modified European Health Literacy Questionnaire [HLS-EU-Q16]) was developed. It was sent to all patients of the Dental Clinic of University of Leipzig who were either 75, 80, or 85 years old (n = 1228). Participation was voluntarily and anonymously; questionnaires had to be returned within six weeks, no reminders were sent. Results: Of the 439 replies (response rate 35.7%), twelve were excluded from data extraction due to disinterest, dementia, or lack of age information. Of the older seniors, 81.5% (n = 348) had utilized at least one dental examination and 54.2% of the dentulous patients (n = 199) had attended at least one dental hygiene appointment within the past year. Up to 55.8% of all participants said it was "difficult" or "very difficult" to find, understand, and use information on COVID-19, especially when judging reliability of information presented in the media, which was especially true for seniors with assigned care levels presenting odds ratios up to 5.30. Conclusions: The investigation revealed a frequent utilization of dental services by older seniors during the COVID-19 pandemic. However, the older seniors encountered difficulties finding, using, and understanding information about COVID-19. Keywords: COVID-19; geriatric dentistry; gerodontology; health literacy; older seniors; utilization

Influence of Manufacturing Regimes on the Phase Transformation of Dental Zirconia

Background: The influence of typical manufacturing regimes for producing fixed dental prostheses (FDPs) from yttria partly-stabilized zirconia polycrystals (3Y/4Y/5Y-TZP) on the phase composition is quantified. Methods: Fixed dental prostheses (FDPs) were designed using a CAD process and machined from different Y-TZP blanks from two manufacturers differing in yttria contents. Subsequent to sintering, the FDPs were glaze fired and air-blasted using alumina particles. Phase composition was determined with X-ray diffraction and quantified with Rietveld refinement. Results: The blanks from VITA Zahnfabrik (VITA YZ HT, VITA YZ ST, VITA YZ XT) and Dental Direct (DD Bio ZX2, DD cube ONE, DD cube X2) featured a rhombohedral portion with rather small crystallites and a small monoclinic portion for 3Y/4Y-TZPs, which increased after machining and disappeared after sintering. Glaze firing and air-blasting with alumina particles had no significant influence on the phase composition. Conclusion: The phase history of dental zirconia is revealed, which may have implications on further processing and aging of the FDP (e.g. low temperature degradation) in mouth

Combination of Digital and Conventional Workflows in the CAD/CAM-Fabrication of an Implant-Supported Overdenture

Completely digital workflows for the fabrication of implant-supported removable restorations are not yet common in clinical dental practice. The aim of the current case report is to illustrate a reliable and comfortable workflow that reasonably merges conventional and digital workflows for the CAD/CAM-fabrication of implant-supported overdentures. The 53-year old patient was supplied with a digitally processed complete denture in the upper jaw and, simultaneously, with an overdenture supported by four interforaminal implants in the lower jaw. The overdenture included a completely digitally processed and manufactured alloy framework that had been fabricated by selective laser sintering. The case report indicates that digital manufacturing processes for extensive and complex removable restorations are possible. However, as it is currently not yet possible to digitally obtain functional impressions, future developments and innovations might focus on that issue

Cross-Contamination Risk of Dental Tray Adhesives: An In Vitro Study

Background: The aim of this study was to investigate the risk of cross-contamination in dental tray adhesives with reusable brush systems. Methods: Four dental tray adhesives with different disinfectant components were examined for risk as a potential transmission medium for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus oralis, and Candida albicans. Bacterial and fungal strains were mixed with artificial saliva. The contaminated saliva was intentionally added to tray adhesive liquid samples. At baseline and up to 60 min, 100 microliters of each sample were collected and cultivated aerobically on Columbia and Sabouraud agar for 24 or 48 h, respectively. Results: At baseline, contamination with Staphylococcus aureus and Candida albicans could be identified in three out of four adhesives. In the subsequent samples, low counts of up to 20 colony-forming units per milliliter could be observed for Staphylococcus aureus. All other strains did not form colonies at baseline or subsequently. Adhesives with isopropanol or ethyl acetate as disinfectant additives were most effective in preventing contamination, while adhesives with hydrogen chloride or acetone as a disinfectant additive were the least effective. Conclusion: Within 15 min, the tested adhesives appeared to be sufficiently bactericidal and fungicidal against all microorganisms tested

Prevalence of temporomandibular disorders and bruxism in seniors

Background Information on the prevalence of temporomandibular disorders (TMD) or possible/probable bruxism in seniors is heterogeneous and sparse. Objectives To elucidate the prevalence of TMD and possible/probable bruxism in German adults aged 60 years and older. Methods Participants of the Interdisciplinary Longitudinal Study of Adult Development and Aging (ILSE) born between 1950–1952 (C1) and 1930–1932 (C2) were examined in 2014–2016 (fourth wave). The participants were surveyed and clinically examined by one calibrated examiner. Two questions of the Patient Health Questionnaire (PHQ) were utilised to evaluate self‐reported bruxism. The clinical examination included signs of probable bruxism and the RDC/TMD examination protocol. Results Data from 191 participants were available. No RDC/TMD diagnosis was made in 83.2%. Of the participants, 15.2% received a single diagnosis and 1.6% multiple diagnoses that included disc displacements (9.4%) and degenerative joint diseases (8.9%). A total of 24.7% reported bruxism that included self‐reported awake bruxism in 11.9% and sleep bruxism in 16.2%. Wear was clinically identified in 27.2% of the participants. No sex‐related differences were observed. Significant differences were detected for probable bruxism between C1 (14.1%) and C2 (54.3%). Conclusion In the German population aged 60 years and older, the prevalence of TMD is 16.8%. TMD is characterised by temporomandibular joint disorders, including disc displacements and degenerative joint disorders. Bruxism was observed in a quarter of the old population

Two-Year Longevity of Posterior Zirconia Multi-Unit Fixed Dental Prostheses with Monolithic Occlusal Surface

In this prospective clinical trial we observed the 2-year clinical performance of posterior tooth-supported multi-unit fixed dental prostheses (FDP) fabricated from zirconia with monolithic occlusal surfaces. Fifty multi-unit FDPs were inserted in 50 patients. After two years of clinical service, 43 restorations were reexamined as one patient had died and six patients were not available for recall. Two biological (root canal treatment: 12 and 14 months) and one technical (debonding: 12 months) complications occurred. According to the Kaplan–Meier analysis, the success rate was 93.7%, and the survival rate was 100%. The six patients who were not available for regular 2-year follow-up were examined after the official 2-year recall interval, and none of the FDPs presented complications or failures. Within the limitations of the current study, the use of multi-unit FDPs with monolithic occlusal surfaces fabricated from zirconia can be recommended for short-term use in the posterior area

CAD/CAM Resin-Based Composites for Use in Long-Term Temporary Fixed Dental Prostheses

The aim of this in vitro study was to analyse the performance of CAD/CAM resin-based composites for the fabrication of long-term temporary fixed dental prostheses (FDP) and to compare it to other commercially available alternative materials regarding its long-term stability. Four CAD/CAM materials [Structur CAD (SC), VITA CAD-Temp (CT), Grandio disc (GD), and Lava Esthetic (LE)] and two direct RBCs [(Structur 3 (S3) and LuxaCrown (LC)] were used to fabricate three-unit FDPs. 10/20 FDPs were subjected to thermal cycling and mechanical loading by chewing simulation and 10/20 FDPs were stored in distilled water. Two FDPs of each material were forwarded to additional image diagnostics prior and after chewing simulation. Fracture loads were measured and data were statistically analysed. SC is suitable for use as a long-term temporary (two years) three-unit FDP. In comparison to CT, SC featured significantly higher breaking forces (SC > 800 N; CT < 600 N) and the surface wear of the antagonists was (significantly) lower and the abrasion of the FDP was similar. The high breaking forces (1100–1327 N) of GD and the small difference compared to LE regarding flexural strength showed that the material might be used for the fabrication of three-unit FDPs. With the exception of S3, all analysed direct or indirect materials are suitable for the fabrication of temporary FDPs