Three-dimensional assessment of internal adaptation measurement of three cad/cam ceramic systems

Abstract This study aimed to evaluate the internal adaptation of three different computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic crowns. The internal adaptation of a polymer-infiltrated ceramic network material (Vita Enamic [VE]) was compared to two machinable glass-ceramics; Zirconia-reinforced lithium silicate (Vita Suprinity [VS]) and a lithium disilicate glass-ceramic (IPS e.max. CAD). Thirty human premolars of average size were prepared (n=10 each group) by computer numerical control to fulfill the criteria of all-ceramic crown design. Optical impressions were taken for each tooth preparation using the CAD/CAM scanner. Thirty crowns were fabricated using CAD/CAM system and divided into three groups (IPS e.max, VE, and VS). To assess the internal fit of tested crowns, the gap between the intaglio of each crown and the corresponding tooth surface was evaluated using a 3D digital scanner using the Triple-scan Protocol. One-way ANOVA followed by Tukey Post Hoc statistical tests were used to statistically analyze results of the internal fit. There was a statistically significant difference for all groups at the four axial walls (p = 0.000002). For total internal fit between groups, comparisons showed a statistically significant difference between all tested groups (p=0.000002). When each pair of groups was statistically compared with each other, all pair comparisons showed a statistically significant difference. IPS e.max CAD had the best internal fit, followed by Vita Enamic, then Vita Suprinity. For all ceramics tested, values of internal fit of all ceramics tested were within the clinically acceptable range.

Resumo Este estudo teve como objetivo avaliar a adaptação interna de três diferentes coroas cerâmicas CAD/CAM (Computer-aided design/computer-aided manufacturing). A adaptação interna de um material cerâmico de rede com infiltração de polímero (Vita Enamic [VE]) foi comparada com duas cerâmicas de vidro maquináveis; silicato de lítio reforçado com zircónio (Vita Suprinity [VS]) e uma cerâmica-vidro de dissilicato de lítio (IPS e.max. CAD). Trinta dentes pré-molares humanos de tamanho médio foram preparados (n=10 cada grupo) por controle numérico computadorizado para preencher os critérios de desenho de coroa em cerâmica pura. Foram tiradas impressões ópticas para cada preparação dentária utilizando o scanner CAD/CAM. Trinta coroas foram fabricadas usando o sistema CAD/CAM e divididas em três grupos (IPS e.max, VE, e VS). Para avaliar o ajuste interno das coroas testadas, o espaço entre o entalhe de cada coroa e a superfície dentária correspondente foi avaliado usando um scanner digital 3D usando o Protocolo Triple-scan. Para analisar estatisticamente os resultados do ajuste interno, utilizou-se a ANOVA unidirecional seguida dos testes estatísticos Tukey Post Hoc. Houve uma diferença estatisticamente significativa para todos os grupos nas quatro paredes axiais (p = 0,000002). Para o ajuste interno total entre grupos, as comparações mostraram uma diferença estatisticamente significativa entre todos os grupos testados (p=0,000002). Quando cada par de grupos foi comparado estatisticamente uns com os outros, todas as comparações de pares mostraram uma diferença estatisticamente significativa. IPS e.max CAD teve o melhor ajuste interno, seguido por Vita Enamic, depois Vita Suprinity. Para todas as cerâmicas testadas, os valores de ajuste interno de todas as cerâmicas testadas encontravam-se dentro da gama clinicamente aceitável.

Effect of additional firing process after sintering of monolithic zirconia crown on marginal and internal fitness / 대한치과보철학회지

PURPOSE: To evaluate an effect of additional firing process after sintering of monolithic zirconia crown on marginal and internal fit through three-dimensional analysis. MATERIALS AND METHODS: Ten monolithic zirconia crowns were fabricated using titanium abutment model. Monolithic zirconia crowns were designed, milled, and sintered as a control group, and additional firing with coloring was performed as a test group. Three dimensional analysis were performed by using triple-scan protocol, and cross-section analysis on mesio-distal and disto-lingual section was evaluated to measure marginal and internal fitness. Then, three-dimensional surface difference on between two groups was evaluated (α=.05). RESULTS: There was statistically significant difference between the control group (32.0 ± 24.3 µm) and the test group (17.0 ± 10.8 µm) in the mesial axial wall (P < .02) and the control group (60.2 ± 24.3 µm) and the test group (71.8 ± 21.5 µm) in the distal axial wall (P < .01). There was no statistically significant difference at the remaining point. CONCLUSION: There was no statistical significance on the deviation of inner surface of crown according to firing number, and the results of both group were considered clinically acceptable.

Marginal and internal fit of all ceramic crown using the replica technique and the triple-scan protocol / 대한치과보철학회지

PURPOSE: This study was conducted to compare the marginal and internal fit of all ceramic crown using the replica technique and the triple-scan protocol. MATERIALS AND METHODS: Twenty zirconia ceramic crowns were fabricated using titanium abutment model. All crowns were divided into two groups of 10 each, depending on the replica technique and the triple-scan protocol. The internal and marginal fit of 10 zirconia ceramic crowns were measured at 17 points for each specimen using the replica technique. The other 10 ceramic crowns were measured using the triple-scan protocol. Statistical analysis was performed by t-test (α= .05). RESULTS: The mean and standard deviation of marginal and internal fit were significantly different between the replica technique (49.86 ± 29.69 µm) and triple-scan protocol (75.35 ± 64.73 µm, P.343). CONCLUSION: There was a statistically significant difference in the marginal fit measured by the two methods. However, there was no statistically significant difference in the internal fit between the two methods.