Antibacterial Effects of Modified Implant Abutment Surfaces for the Prevention of Peri-Implantitis—A Systematic Review

The aim of the present study was to systematically review studies investigating antibacterial implant abutment surfaces or coatings, which may suppress bacterial growth to prevent plaque-induced peri-implant inflammatory disease. Data were collected after identification of case, assay/laboratory procedure, predicate/reference standard and outcome (CAPO). Seven hundred and twenty (720) records were identified through data base searching. After screening nine publications fulfilled inclusion criteria and were included. The following surfaces/coatings showed antibacterial properties: Electrochemical surface modification of titanium by the anodic spark deposition technique; doxycycline coating by cathodic polarization; silver coating by DC plasma sputter; titanium nitride; zirconium nitride and microwave assistant nano silver coating. Since the current state of the literature is rather descriptive, a meta-analysis was not performed. While several abutment coatings showed to have antibacterial capacity, some of them also influenced the behavior of investigated human cells. None of the studies investigated the long-term effect of surface modifications. Since surface changes are the main contributing factor in the development of antibacterial effects, the biodegradation behavior must be characterized to understand its durability. To date there is no effective structure, material or strategy to avoid peri-implant inflammation used as clinical routine. Furthermore, clinical studies are scarce

Stereolithography vs. Direct Light Processing for Rapid Manufacturing of Complete Denture Bases: An In Vitro Accuracy Analysis

The topical literature lacks any comparison between stereolithography (SLA) and direct light processing (DLP) printing methods with regard to the accuracy of complete denture base fabrication, thereby utilizing materials certified for this purpose. In order to investigate this aspect, 15 denture bases were printed with SLA and DLP methods using three build angles: 0°, 45° and 90°. The dentures were digitalized using a laboratory scanner (D2000, 3Shape) and analyzed in analyzing software (Geomagic Control X, 3D systems). Differences between 3D datasets were measured using the root mean square (RMS) value for trueness and precision and mean and maximum deviations were obtained for each denture base. The data were statistically analyzed using two-way ANOVA and Tukey's multiple comparison test. A heat map was generated to display the locations of the deviations within the intaglio surface. The overall tendency indicated that SLA denture bases had significantly higher trueness for most build angles compared to DLP (p < 0.001). The 90° build angle may provide the best trueness for both SLA and DLP. With regard to precision, statistically significant differences were found in the build angles only. Higher precision was revealed in the DLP angle of 0° in comparison to the 45° and 90° angles

Restoration of 1325 teeth with partial-coverage crowns manufactured from high noble metal alloys: a retrospective case series 18.8 years after prosthetic delivery

Objectives: To evaluate long-term survival and success rates of conventionally cemented partial-coverage crowns (PCCs) manufactured from high noble metal alloys (hn). Material and methods: Restoration-, periodontal- and tooth-related criteria on patients, restored with a single or multiple conventionally cemented hnPCCs in a private dental office were collected from existing patient records. With regard to semi-annual follow-ups, data of the most recent clinical evaluations were considered. Kaplan-Meier and log-rank tests were used for statistical analyses. Level of significance was set at p <= .05. Results: Between 09/1983 and 09/2009, 1325 hnPCCs were conventionally cemented on 1325 teeth in 266 patients (mean age: 44.5 +/- 10.7 years). Due to various reasons, 81 hnPCCs showed complications, documenting a success rate of 93.9% after a mean observation period of 18.8 +/- 5.7 years. Of these, additional 14 restorations were counted as survival, resulting in a survival rate of 94.9%. Most frequent complications were periodontal issues (n = 29, 35.8%). Significantly higher success rates were documented for hnPCCs of patients aged between 37 and 51 years (p = .012). Conclusion: Partial-coverage crowns from high noble metal alloys showed excellent survival and success rates after a mean observation period of 18.8 +/- 5.7 years. Higher patient age was one of the risk factors. Clinical relevance: According to the results of this study, hnPCCs still represent an excellent therapeutic option-even in modern dentistry

Microstructural investigation of hybrid CAD/CAM restorative dental materials by micro-CT and SEM

Objectives: An increasing number of CAD/CAM (computer-aided design/computer-aided manufacturing) hybrid materials have been introduced to the dental market in recent years. In addition, CAD/CAM hybrid materials for additive manufacturing (AM) are becoming more attractive in digital dentistry. Studies on material microstructures using micro-computed tomography ($\mu$-CT) combined with scanning electron microscopy (SEM) have only been available to a limited extent so far. Methods: One CAD/CAM three-dimensional- (3D-) printable hybrid material (VarseoSmile Crown plus) and two CAD/CAM millable hybrid materials (Vita Enamic; Voco Grandio), as well as one direct composite material (Ceram.x duo), were included in the present study. Cylindrical samples with a diameter of 2 mm were produced from each material and investigated by means of synchrotron radiation $\mu$-CT at a voxel size of 0.65 $\mu$m. Different samples from the same materials, obtained by cutting and polishing, were investigated by SEM. Results: The 3D-printed hybrid material showed some agglomerations and a more irregular distribution of fillers, as well as a visible layered macrostructure and a few spherical pores due to the printing process. The CAD/CAM millable hybrid materials revealed a more homogenous distribution of ceramic particles. The direct composite material showed multiple air bubbles and microstructural irregularities based on manual processing. Significance: The $\mu$-CT and SEM analysis of the materials revealed different microstructures even though they belong to the same class of materials. It could be shown that $\mu$-CT and SEM imaging are valuable tools to understand microstructure and related mechanical properties of materials.Comment: 22 pages, 3 tables, 11 figures including supplementary materia

Clinical Outcomes of Root-Analogue Implants Restored with Single Crowns or Fixed Dental Prostheses: A Retrospective Case Series

The objective was to investigate clinical and radiological outcomes of rehabilitations with root-analogue implants (RAIs). Patients restored with RAIs, supporting single crowns or fixed dental prostheses, were recruited for follow-up examinations. Besides clinical and esthetical evaluations, X-rays were taken and compared with the records. Patients were asked to evaluate the treatment using Visual Analogue Scales (VAS). For statistical analyses, mixed linear models were used. A total of 107 RAIs were installed in one dental office. Of these, 31 were available for follow-up examinations. For those remaining, survival has been verified via phone. RAIs were loaded after a mean healing time of 6.6 ± 2.5 months. 12.1 ± 6.9 months after loading, a mean marginal bone loss (MBL) of 1.20 ± 0.73 mm was measured. Progression of MBL significantly decreased after loading (p = 0.013). The mean pink and white esthetic score (PES/WES) was 15.35 ± 2.33 at follow-up. A survival rate of 94.4% was calculated after a mean follow-up of 18.9 ± 2.4 months after surgery. Immediate installation of RAIs does not seem to reduce MBL, as known from the literature regarding screw-type implants, and might not be recommended for daily routine. Nevertheless, they deliver esthetically satisfying results

Wearing complete dental prostheses - Effects on perioral morphology

Background: To adequately perform rehabilitation of edentulous patients by a complete removable dental prosthesis (CRDP) is from basic interest to dentists to understand the morphologic changes caused by re-establishment of a physiologic jaw relationship. Anthropometric analyses of standardized frontal view and profile photographs may help elucidate such changes. Material and Methods: Photographs of 31 edentulous patients were compared in relaxed lip closure and after insertion of a CRDP in stable occlusion. 2232 anthropometric distances were raised. Eighteen anthropometric indices reflecting the perioral morphology and its integration in the vertical facial harmony were investigated. Results: The intercanthal – mouth width index ( p <.001), medial – lateral cutaneous upper lip height index ( p= .007), lower vermilion contour index ( p= .022), vermilion – total upper lip height index ( p= .018), cutaneous – total up - per lip height index ( p= .023), upper lip – nose height index ( p= .001), nose – upper face height index ( p= .002), chin – mandible height index ( p= .013), upper lip – mandible height index ( p= .045), nose – lower face height index ( p= .018), and nose - face height index ( p= .029) showed significant pre- to post-treatment changes. Conclusions: The investigated anthropometric indices presented reproducible results related to an increase in occlusal vertical dimension. Their application may be helpful in assessment, planning, and explanation of morphologic effects of CRDPs on the perioral and overall facial morphology, which may helps to improve the aesthetic outcome

Prosthetic treatment patterns in the very old: an insurance database analysis from Northeast Germany

Objectives: We assessed dental prosthetic services utilization in very old Germans. Methods: A comprehensive sample of 404,610 very old (≥ 75 years), insured at one large statutory insurer (Allgemeine Ortskrankenkasse Nordost, acting in the federal states Berlin, Brandenburg, Mecklenburg-Vorpommern), were followed over 6 years (2012-2017). Our outcome was the utilization of prosthetic services, in total and seven subgroups: (1) Crowns/partial crowns, (2) fixed dental prostheses (FDPs), (3) partial removable prostheses (RDPs), (4) full RDPs, (5) temporary services, (6) relining/rebasing/repairing/extending RDPs, (7) repairing FDPs. Association of utilization with (1) gender, (2) age, (3) region, (4) social hardship status, (5) ICD-10 diagnoses and (6) German diagnoses related groups (G-DRG) was explored. Results: The mean (SD) age of the sample was 81.9 (5.4) years; mean follow-up was 1689 (705) days. The mean utilization of any prosthetic service was 27.0%; the most often utilized service type were total RDPs (13.2% utilization), crowns (8.1%), and partial RDPs (7.1%). Utilization decreased with age for nearly all services (except relining/rebasing/repairing/extending RDPs). Utilization of prosthetic services was significantly higher in Berlin and most cities compared with rural municipalities and in individuals with common, less severe conditions according to ICD-10 and DRGs compared with life-threatening conditions or dementia. In multivariable analysis, gender (OR; 95% CI: 0.95; 0.93-0.98), social hardship status (1.19; 1.17-1.21), federal state (Brandenburg 0.57; 0.56-0.59; Mecklenburg-Vorpommern: 0.66; 0.64-0.67) and age significantly affected utilization (0.95; 0.95-0.95/year). Conclusions: Patient-related and healthcare factors determine the utilization of prosthetic services in very old Germans. Interventions to maintain sufficient prosthetic care up to high age are required. Clinical significance: The utilization of prosthetic services in the very old in Northeast Germany showed significant disparities within populations and service types. There seems to be great need to better understand the drivers of utilization, and to develop and evaluate interventions to maintain sufficient prosthetic care up to high age

Marginal and internal fit of zirconia based fixed dental prostheses fabricated with different concepts

Florian Beuer1, Natalie Korczynski1, Antonia Rezac1, Michael Naumann2, Wolfgang Gernet1, John A Sorensen31Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany; 2Department of Prosthodontics and Material Sciences, University of Ulm, Germany; 3Pacific Dental Institute, Portland, Oregon, USAAbstract: The purpose of this in vitro study was to compare the precision of fit of substructures milled from semi-sintered zirconia blocks, fabricated with two different fabrication concepts. Three-unit, posterior fixed dental prostheses (FDP) were fabricated for standardized dies (n = 10) with the laboratory Computer Aided Design (CAD)/Computer Aided Manufacturing (CAM) system Cercon&amp;reg; Brain (Brain) and the centralized CAD/CAM system Compartis Integrated Systems (Compartis). After cementation to the dies, the FDP were embedded and sectioned. Four cross-sections were made of each abutment tooth, and marginal and internal fit were evaluated under an optical microscope. A one-way analysis of variance (ANOVA) was used to compare data (&amp;alpha; = 0.05). Mean gap dimensions at the marginal opening for Brain and Compartis were 56.0 (&amp;plusmn;34.5) &amp;mu;m and 51.7 (&amp;plusmn;45.2) &amp;mu;m, respectively. Mean internal gap dimensions of 62.8 (&amp;plusmn;37.5) &amp;mu;m to 164.6 (&amp;plusmn;33.4) &amp;mu;m were measured depending on the measurement location and the fabrication concept. Mean marginal openings and internal adaptations were not significantly different for both systems. Three out of four measurement locations showed significantly different cement gaps. Within the limitations of this study, the results suggest that the accuracy of both investigated systems is satisfactory for clinical use. The laboratory fabrication exhibited similar accuracy as the centralized manufacturing.Keywords: zirconia, CAD/CAM, fit, FDP, all-cerami