RESUMEN
OBJECTIVE: To evaluate the effect of the deterioration of computer aided design/computer aided manufacturing (CAD/CAM) burs during zirconia milling, on surface roughness, contact angle, and fibroblast viability. MATERIALS AND METHODS: Ceramic blocks were milled and 75 ceramic disks (8 × 1.5 mm) made and allocated into three groups (n = 25): G1-brand new 2L and 1L burs, G2-2L bur at the end of lifetime and brand new 1L bur and G3-both burs at the end of their lifetimes. Roughness (Ra, Rq, and Rz) was evaluated using a 3D optical profilometer, the contact angle by the sessile drop method and the cell viability of the mouse NIH/3T3 fibroblast, using the Alamar Blue assay at intervals of 24, 48, and 72 h (ISO 10993-5). Data were analyzed by one-way ANOVA and Kruskal-Wallis tests (p ≤ 0.05). RESULTS: Roughness increased as the burs deteriorated and G3 (0.27 ± 0.04) presented a higher value for Ra (p < 0.001). The highest contact angle was observed in G3 (86.2 ± 2.66) when compared with G1 (63.7 ± 12.49) and G2 (75.3 ± 6.36) (p < 0.001). Alamar Blue indicated an increase in cell proliferation, with no significant differences among the groups at 24 and 72 h (p > 0.05). CONCLUSIONS: The deterioration of the burs increased the surface roughness and decreased the wettability, but did not interfere in cell viability and proliferation. CLINICAL SIGNIFICANCE: The use of custom zirconia abutments represents an effective strategy for single crowns restorations. Our findings suggest that these abutments can be efficiently milled using CAD/CAM burs within their recommended lifetime.
Asunto(s)
Diseño Asistido por Computadora , Propiedades de Superficie , Circonio , Circonio/química , Ratones , Animales , Pilares Dentales , Materiales Biocompatibles , Células 3T3 NIH , Ensayo de MaterialesRESUMEN
OBJECTIVES: The objective of the study was to assess the impact of periodontal crown lengthening surgery on clinical parameters at adjacent and non-adjacent sites compared to treated sites. MATERIAL AND METHODS: An electronic search was carried out on MEDLINE-PubMed, The Cochrane Library, and ISI Web of Science databases between 1978 and 2015. Methodological quality assessment was based on Cochrane recommendations. Meta-analyses were assessed with RevMan 5.0 and heterogeneity between studies by the Higgin test (I 2). Clinical attachment level (CAL) and probing depth (PD) were the primary outcome variables. Four case series studies were included and three in the meta-analysis. All studies showed high risk of bias. RESULTS: The surgery promoted significant changes in treated, adjacent, and non-adjacent sites. There were greater changes in PD (mean difference -0.14, 95 % CI -0.18 to -0.10, p < 0.00001) and CAL (mean difference 0.16, 95 % CI 0.13 to 0.20, p < 0.00001) in treated sites when compared to adjacent and non-adjacent sites for PD (mean difference -0.09, 95 % CI -0.12 to -0.05, p < 0.00001) and CAL (mean difference 0.91, 95 % CI 0.87 to 0.94, p < 0.00001). CONCLUSION: Crown lengthening surgery results in changes of clinical parameters in treated, adjacent, and non-adjacent sites. CLINICAL RELEVANCE: Clinical and esthetic alterations on the adjacent/non-adjacent teeth can lead to clinical and esthetic alterations, which must be considered in surgical planning.