Influence of the Transmucosal Surface of Dental Implants on the Soft Tissue Attachment Level and Marginal Bone Loss in Preclinical Studies: A Systematic Review.

PURPOSE: To determine the characteristics of dental implant transmucosal surfaces that influence soft tissue attachment and marginal bone loss (MBL). MATERIALS AND METHODS: The PubMed, Embase, and Cochrane Library electronic databases were searched based on predefined PICO eligibility criteria. Data from animal studies that compared junctional epithelium and connective tissue attachment and MBL from 4 days to 72 weeks were analyzed. The risk of bias was performed with the Systematic Review Centre for Laboratory Animal Experimentation tool. A rank analysis evaluation of data was performed, and the most frequently appearing materials/surfaces for each tissue compartment were identified. RESULTS: The search identified 3,549 studies, 28 of which were eligible for analysis, with an average risk of bias of 28% ± 10%. Machined, polished, etched, sandblasted, or coated titanium and zirconia materials/surfaces were most frequently examined. Several studies investigated lithium disilicate, polyether ether ketone (PEEK) or polyether ketone ketone (PEKK), aluminum oxide, and gold. Based on ranking and frequency of use at different time points, titanium grade IV (Ti-4) microthreads with a polished neck area most frequently supported natural tooth-like junctional epithelial attachment (≤ 1.5 mm), while machined Ti-4 and machined titanium grade V (Ti-5) most frequently supported connective tissue attachment (≤ 1.25 mm) and led to the least MBL (≤ 0.75 mm). CONCLUSIONS: Analyzed data suggest that Ti-4 microthreads with a polished neck area and machined Ti-4 and Ti-5 were the materials/surfaces of choice for the transmucosal part of implants. However, the extensive heterogeneity in reported studies precludes solid identification of the best materials/surfaces.

Clinical success of zirconium oxide posts with resin composite or glass-ceramic cores in endodontically treated teeth: a 4-year retrospective study.

PURPOSE: This study retrospectively evaluated zirconium oxide posts with either direct resin composite cores or indirect glass-ceramic cores after several years of clinical service. MATERIALS AND METHODS: One hundred forty-five endodontically treated teeth in 88 patients were restored with zirconium oxide posts; 87 teeth were restored with direct composite cores, and 58 were restored with Empress cores prior to crowning. Seventy-nine posts with direct composite cores in 52 patients and 34 posts with glass-ceramic cores in 19 patients were reevaluated clinically and radiographically after a mean clinical service of 57.7 months and 46.3 months, respectively. RESULTS: Periodontal probing depths remained on a healthy clinical level, and esthetics were judged excellent for the majority of teeth in both groups. In the group with direct composite cores, no failures were observed in the 79 posts that were reevaluated. In the group with indirect glass-ceramic cores, three failures were observed after 42, 43, and 55 months of clinical service. All failures were due to loss of retention. In a best-case scenario posts that could not be reevaluated were considered successful, and in a worst-case scenario they were considered failures; respective success rates were 100% and 91% in the direct group and 95% and 53% in the indirect group. CONCLUSION: The observed clinical success of zirconium oxide posts with direct composite cores suggests that this method of post-and-core reconstruction is clinically promising. Zirconium oxide posts with indirect glass-ceramic cores displayed a significantly higher failure rate and a high dropout rate that precludes valid conclusions.

Conventional visual vs spectrophotometric shade taking for porcelain-fused-to-metal crowns: a clinical comparison.

This study tested the shade match of single porcelain-fused-to-metal restorations with the adjacent dentition when the restorations were fabricated according to data from conventional visual shade matching or from a new spectrophotometric system. The samples of a Vita Classic shade guide were measured with the spectrophotometer to determine the CIE L*a*b* color parameters. Three clinicians independently selected the best match to a maxillary right or left incisor needing a restoration in 10 patients. The 10 incisors were then measured using a reflectance spectrophotometer. CIE L*a*b* coordinates were directly recorded on the spectrophotometer's detector area using a standard light source. Resulting conventional and spectrophotometric restorations were tested intraorally for best match with the adjacent incisor using conventional shade matching versus spectrophotometric measuring. Total color difference was calculated, and all groups were statistically analyzed. Initial shade evaluation matched for all three visual shade selections in two cases. In six cases only two evaluators matched, and in the remaining two cases all three visual selections differed. In contrast, in nine of 10 cases all three spectrophotometric shade selections matched. Additionally, in nine of 10 cases delta E values of visually assessed tooth shades were higher than spectrophotometrically assessed delta E values. Resulting delta E values for conventional crowns compared to spectrophotometric crowns were significantly higher. Finally, in nine of 10 cases spectrophotometric crowns were preferred over conventional crowns for definitive cementation when evaluated visually. Spectrophotometric shade analysis and communication can be used efficiently for fabrication of porcelain-fused-to-metal restorations.