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Background This study aimed to compare and evaluate the marginal fit of nanocomposite computer-aided design/computer-aided manufacturing (CAD/CAM) inlays. Three types of nanocomposite CAD/CAM blocks (HASEM, VITA Enamic, and Lava Ultimate) were used as materials. Methods Class II disto-occlusal inlay restorations were prepared on a typodont mandibular right first molar using diamond rotary instruments. The inlays were fabricated using CAD/CAM technology and evaluated using the silicone replica technique to measure marginal gaps at five locations on each inlay. The data were analyzed by two-way analysis of variance and Tukey post hoc tests (α=0.05). Results There were no significant differences in the marginal gaps based on the type of nanocomposite CAD/CAM inlay used (p=0.209). However, there was a significant difference in the marginal gaps between the measurement regions. The gingival region consistently exhibited a larger marginal gap than the axial and occlusal regions (p

PURPOSE. The aim of this stuldy was to compare the clinical marginal fit of CAD-CAM inlays obtained from intraoral digital impression or addition silicone impression techniques. MATERIALS AND METHODS. The study included 31 inlays for prosthodontics purposes of 31 patients: 15 based on intraoral digital impressions (DI group); and 16 based on a conventional impression technique (CI group). Inlays included occlusal and a non-occlusal surface. Inlays were milled in ceramic. The inlay-teeth interface was replicated by placing each inlay in its corresponding uncemented clinical preparation and taking interface impressions with silicone material from occlusal and free surfaces. Interface analysis was made using white light confocal microscopy (WLCM) (scanning area: 694 × 510 µm2) from the impression samples. The gap size and the inlay overextension were measured from the microscopy topographies. For analytical purposes (i.e., 95-%-confidence intervals calculations and P -value calculations), the procedure REGRESS in SUDAAN was used to account for clustering (i.e., multiple measurements). For p-value calculation, the log transformation of the dependent variables was used to normalize the distributions. RESULTS. Marginal fit values for occlusal and free surfaces were affected by the type of impression. There were no differences between surfaces (occlusal vs. free). Gap obtained for DI group was 164 ± 84 µm and that for CI group was 209 ± 104 µm, and there were statistical differences between them (p = .041). Mean overextension values were 60 ± 59 µm for DI group and 67 ± 73 µm for CI group, and there were no differences between then (p = .553). CONCLUSION. Digital impression achieved inlays with higher clinical marginal fit and performed better than the conventional silicone materials. [ABSTRACT FROM AUTHOR]

Abstract Background This study evaluates the mechanical performance of deep margin elevation technique for carious cavities by considering the shape designs and material selections of inlay using a computational approach combined with the design of experiments method. The goal is to understand the effects of the design parameters on the deep margin elevation technique and provide design guidelines from the biomechanics perspective. Methods Seven geometric design parameters for defining an inlay’s shape of a premolar were specified, and the influence of cavity shape and material selection on the overall stress distribution was investigated via automated modelling. Material selection included composite resin, ceramic, and lithium disilicate. Finite element analysis was performed to evaluate the mechanical behavior of the tooth and inlay under a compressive load. Next, the analysis of variance was conducted to identify the parameters with a significant effect on the stress occurred in the materials. Finally, the response surface method was used to analyze the stress responses of the restored tooth with different design parameters. Results The restored tooth with a larger isthmus width demonstrated superior mechanical performance in all three types of inlay materials, while the influence of other design parameters varied with the inlay material selection. The height of the deep margin elevation layer insignificantly affected the mechanical performance of the restored tooth. Conclusions A proper geometric design of inlay enhances the mechanical performance of the restored tooth and could require less volume of the natural dentin to be excavated. Furthermore, under the loading conditions evaluated in this study, the deep margin elevation layer did not extensively affect the strength of the tooth structure.

Dental modifications, especially dental inlays, were one of the most characteristic biocultural traditions in Ancient Mesoamerica. The main objective of this brief report is to identify the raw material used to elaborate dental inlays in the archaeological site of Reynosa, located in the Southern Pacific Coast of Guatemala. The recent discovery of a massive burial, dated roughly in the Middle-Late Preclassic Period (500 BC–200 BC), put the site in the spotlight. There were found some of the earliest carriers of dental incrustations in Mesoamerica, which represent part of the beginning of the inlay tradition. The analytical method used to determine the raw material was scanning electron microscopy (SEM) with X-ray spectroscopy. The identified raw materials were pyrite and hematite. These findings have opened new concerns about the obtaining and the usage of those materials in this millennial tradition.

Background: This study evaluates the mechanical performance of deep margin elevation technique for carious cavities by considering the shape designs and material selections of inlay using a computational approach combined with the design of experiments method. The goal is to understand the effects of the design parameters on the deep margin elevation technique and provide design guidelines from the biomechanics perspective. Methods: Seven geometric design parameters for defining an inlay's shape of a premolar were specified, and the influence of cavity shape and material selection on the overall stress distribution was investigated via automated modelling. Material selection included composite resin, ceramic, and lithium disilicate. Finite element analysis was performed to evaluate the mechanical behavior of the tooth and inlay under a compressive load. Next, the analysis of variance was conducted to identify the parameters with a significant effect on the stress occurred in the materials. Finally, the response surface method was used to analyze the stress responses of the restored tooth with different design parameters. Results: The restored tooth with a larger isthmus width demonstrated superior mechanical performance in all three types of inlay materials, while the influence of other design parameters varied with the inlay material selection. The height of the deep margin elevation layer insignificantly affected the mechanical performance of the restored tooth. Conclusions: A proper geometric design of inlay enhances the mechanical performance of the restored tooth and could require less volume of the natural dentin to be excavated. Furthermore, under the loading conditions evaluated in this study, the deep margin elevation layer did not extensively affect the strength of the tooth structure. [ABSTRACT FROM AUTHOR]

Dental modifications, especially dental inlays, were one of the most characteristic biocultural traditions in Ancient Mesoamerica. The main objective of this brief report is to identify the raw material used to elaborate dental inlays in the archaeological site of Reynosa, located in the Southern Pacific Coast of Guatemala. The recent discovery of a massive burial, dated roughly in the Middle-Late Preclassic Period (500 BC–200 BC), put the site in the spotlight. There were found some of the earliest carriers of dental incrustations in Mesoamerica, which represent part of the beginning of the inlay tradition. The analytical method used to determine the raw material was scanning electron microscopy (SEM) with X-ray spectroscopy. The identified raw materials were pyrite and hematite. These findings have opened new concerns about the obtaining and the usage of those materials in this millennial tradition. [ABSTRACT FROM AUTHOR]

Dental modifications, especially dental inlays, were one of the most characteristic biocultural traditions in Ancient Mesoamerica. The main objective of this brief report is to identify the raw material used to elaborate dental inlays in the archaeological site of Reynosa, located in the Southern Pacific Coast of Guatemala. The recent discovery of a massive burial, dated roughly in the Middle-Late Preclassic Period (500 BC–200 BC), put the site in the spotlight. There were found some of the earliest carriers of dental incrustations in Mesoamerica, which represent part of the beginning of the inlay tradition. The analytical method used to determine the raw material was scanning electron microscopy (SEM) with X-ray spectroscopy. The identified raw materials were pyrite and hematite. These findings have opened new concerns about the obtaining and the usage of those materials in this millennial tradition. [ABSTRACT FROM AUTHOR]