Comparative Accuracy of Intraoral and Extraoral Digital Workflows for Short Span Implant Supported Fixed Partial Denture Fabrication: An In Vitro Study.

BACKGROUND The advent of digital impressions using computer-aided design and manufacturing technology (CAD/CAM) has simplified and improved the fabrication of implant prostheses in dentistry. The conventional impression has several drawbacks, including tray selection, material type, impression technique, impression disinfection, and cast model storage. The inaccuracies caused by distortion and contraction of impression material can be minimized with digital impressions. This study aimed to compare digital dental impressions of 10 working casts made using the Pindex laser removable die system to fabricate parallel drill channels vs 10 working casts made using the Di-Lok plastic tray removable die system. MATERIAL AND METHODS An implant master die with 2 dental implant analogs was fabricated. Ten working casts using the Pindex laser removable die system with parallel drill channels and 10 working casts using the Di-Lok plastic tray removable die system were fabricated. The working casts were scanned using an extra-oral laboratory scanner and the implant master model was scanned with an intra-oral scanner. RESULTS The properties of the casts made using the 2 systems were evaluated and analyzed with ANOVA and post hoc Tukey test. The mean horizontal linear distances between A1B1 (P<0.021), A2B2 (P<0.018), C1D1 (P<0.026), C2D2 (P<0.03), B1C1 (P<0.01), and mean vertical distances between B1A2 (P<0.015), C1D2 (P<0.001), B1B2 (P<0.028), and C1C2 (P<0.001) were significantly different between the Pindex system and Di-Lok tray system as compared to intra-oral scans. CONCLUSIONS Complete digital workflow with intra-oral scans were more than the partial digital workflow with extra-oral scans for the Pindex system and Di-Lok tray systems.

Impact of Auxiliary Features on Retention of Short Dental Crowns: An In-Vitro Analysis of Box and Groove Preparations.

BACKGROUND Several auxiliary features have been proposed to achieve sustainable retention for short-prepared dental crowns; however, achieving retention is challenging. This study aimed to assess the impact of increased total occlusal convergence and auxiliary preparation factors like box and groove on the retention form of short tooth preparations. MATERIAL AND METHODS Eighty resin machine-milled dies with a height of 3 mm and a deep chamfer margin of 1 mm were prepared to mimic the short-prepared molar. Initially, 2 teeth were prepared following the guidelines, and the total occlusal convergence was kept at 10° and 20°, respectively. Auxiliary features such as the proximal box and buccal groove were prepared on separate 20° dies. Eighty dies were prepared with 10 samples each for 10°, 20°, 20° with proximal box and 20° with buccal groove for zirconia (n=40) and metal crowns (n=40). Cementation was done with glass ionomer luting cement, and a pull-off test was conducted. Data were analyzed using one-way analysis of variance and post hoc fisher least significant difference test (P<0.05). RESULTS The highest mean was observed in the proximal box group with the metal crown (14.59), and the lowest in the group with 20° zirconia crowns (9.12). Within groups, the highest retentive values were found for the 20° taper with proximal box preparation; the lowest was for the 20° taper group. CONCLUSIONS Within the study limitations, it could be concluded that incorporating a proximal box or buccal groove in short tooth preparations with an increased total occlusal convergence improved retentive values.

Rehabilitation of Ectodermal Dysplasia Using CAD/CAM Mandibular Complete Denture and Maxillary Overdenture: A Clinical Report.

Ectodermal dysplasia is a genetic disorder characterized by the abnormal development of two or more ectodermally driven structures, leading to various clinical manifestations such as sparse hair, dry skin, and hypodontia or anodontia. The absence of teeth significantly impacts the quality of life for individuals affected by this condition. This article presents a clinical case report of a patient with ectodermal dysplasia who underwent full mouth rehabilitation using computer-aided design/computer-aided manufacturing (CAD/CAM) technology to fabricate a mandibular complete denture and a maxillary overdenture.

A novel digital workflow for fabricating artificial periodontal ligament using three-dimensional printing flexible resin: A dental technique.

The fabrication of periodontal ligament (PDL) models for in vitro dental studies has seen a wide range of techniques and materials being utilized. This paper introduces a novel dental technique that employs a digital workflow for the fabrication of artificial PDL using three-dimensional printing of flexible resin. This innovative approach offers several advantages, including enhanced accuracy and realism in simulating PDL. The digital workflow facilitates a streamlined fabrication process, ensuring efficiency and precision. By presenting this novel technique, this digital approach contributes to the advancement of in vitro dental research, providing researchers with a reliable and realistic model for studying various dental phenomena.

Digital workflow for duplication of gold onlay anatomy to monolithic zirconia onlay for a complete denture: A technique paper.

Digital replication of an existing cast gold onlay anatomy to a more esthetic material for a new complete denture is challenging. A technique is presented that uses digital technology to fabricate a new maxillary complete denture with monolithic zirconia onlays that duplicate the anatomy of an existing complete denture with cast gold onlays.

Digital beading for a CAD-CAM framework for an implant-supported overdenture: A dental technique.

The analog technique of making bead lines for a metal superstructure framework for the maxillary implant-supported overdenture is created by scribing shallow grooves on the surface of a definitive gypsum cast. This report describes a digital technique that uses computer-aided design and computer-aided manufacturing technology to make dental bead lines on an intraoral impression without using the gypsum cast.