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.

Prevalence of mandibular asymmetries in the pediatric population of Jazan: A radiographic analytical study.

Background: Facial asymmetry results from variation in mandibular linear and angular dimensions on the right and left sides of the face. Mandibular asymmetry is of great significance to oral surgeons and orthodontists as it directly impacts the facial profile of an individual. Aim: The present study aimed to measure the prevalence of mandibular asymmetry and its fluctuations during the mixed dentition growth phase in healthy children aged 6-8 years in the Jazan region of Saudi Arabia. Method: This retrospective observational study was conducted by measuring linear asymmetrical measurements of mandible on orthopantomograms of 390 healthy children (182 boys and 208 girls, aged 6-8 years) with mixed dentition. Linear measurements from orthopantomograms were obtained using a standardized digitizer. Two sets of mandibular measurements were recorded, alongside subjective assessments of mandibular first molar development. An independent t-test was employed to assess the significance between measurements on both sides, while one-way ANOVA was used to demonstrate facial asymmetry significance among different age groups. Result: The result of this study revealed a significant statistical difference (p-value≤ 0.05) for both sides of the mandible across two dimensions: condylar and ramus height (p value = 0.03) and mandibular length (p value = 0.04). The asymmetry index resulted in no asymmetry among most of the included subjects. However, compared to the other three linear measurements, many seven-year-old participants possess mandibular asymmetry on condylar height (54.5 %). Conclusion: Within the limitation it could be concluded that children in growing age have a significant mandibular asymmetry (mainly 7 years), which, however, is only seldom clinically significant. Hence, treatment plan should be cautiously planned.