Introduction: In orthodontics, determining the parameters of tooth size and dental arch and conducting Bolton analysis is crucial for diagnosis, treatment planning, and patient outcomes. This study evaluates the accuracy and reliability of measuring dental-arch dimensions on digital models created using the CEREC Primescan intraoral scanner, compared to measurements taken from plaster models. Methods: The study included two types of dental models (plaster and intraoral scan) from sixty-three subjects. Impressions were taken to create plaster models, and the subjects’ mouths were scanned with the CEREC Primescan system (Dentsply Sirona, Charlotte, NC) to create digital models. Intra-arch measurements included tooth heights and widths, overjet, and overbite. The arch width and depth were examined at the first permanent upper or lower molar. The paired t-test and Bland–Altman plot were used to determine the accuracy, while intra-rater and inter-rater correlation coefficient values were calculated to assess the reliability of measurements from the intraoral scan compared to those from the plaster model. Results: For tooth heights, there was a statistically significant difference in only one measurement (tooth 34) between the plaster and digital models, with an average difference of 0.01 mm. For tooth widths, there was a statistically significant difference in only one measurement (tooth 15) with an average difference of 0.03 mm. The Bland–Altman plots of almost all of measurements of tooth heights and widths showed that differences between the two models were within the limits of agreement. The inter- and intra-rater correlation coefficient values for measurements on the digital model were found to be statistically insignificant. Conclusion: Measuring dental dimensions on digital models obtained through the Primescan intraoral digital system yielded similar results to those obtained from plaster models and showed excellent reliability, indicating its potential application in clinical practice.

Objective: This in vitro study aimed to evaluate and compare the trueness and precision of four extraoral 3D facial scanning systems using a standardized 3D-printed human head model. Methods: A 3D-printed head model with 16 anatomical landmarks and 17 inter-landmark linear distances was fabricated using a high-resolution 3D printer. Caliper measurements were used as reference standards. The model was scanned 15 times by four systems: a handheld scanner (MetiSmile, Shining 3D, Hangzhou, China), a desktop scanner (RAYFace v2.0, Ray Co., Seongnam, Gyeonggi-do, Republic of Korea), and two mobile applications (Heges and Polycam, iPhone 15, Apple Inc., Cupertino, CA, USA). All digital distances were measured in Blender software. To assess intra-observer reliability, all measurements were repeated twice by the same examiner with a 3-week interval between sessions, and intra-class correlation coefficients were calculated using a two-way mixed-effects, single-measurement, absolute-agreement model (ICC 3,1). Trueness, defined as the absolute deviation from the reference caliper values, was compared across scanners using the Kruskal–Wallis test due to its non-normal distribution. Precision, regional trueness and precision values across the four scanners defined as the standard deviation of repeated scans, was analyzed using One-way ANOVA with Tukey post-hoc comparisons for normally distributed datasets (α = 0.05). Distances were measured digitally in Blender software, and trueness (absolute deviation from reference) and precision (standard deviation of repeated scans) were analyzed using the Kruskal–Wallis test and One-way ANOVA with Tukey post hoc comparisons (α = 0.05). Results: The Polycam application demonstrated the highest trueness (0.49 ± 0.32 mm), followed by MetiSmile (0.51 ± 0.36 mm), RAYFace (0.58 ± 0.39 mm), and Heges (0.73 ± 0.42 mm). The MetiSmile scanner showed the highest precision (0.12 ± 0.07 mm), while RAYFace and Polycam exhibited moderate precision (0.28 ± 0.19 mm and 0.15 ± 0.06 mm, respectively). Vertical measurements tended to be more accurate than horizontal ones, and the lower facial region showed smaller deviations; however, these differences were not statistically significant (p > 0.05). Conclusions: MetiSmile achieved the highest precision and Polycam the highest trueness. Although all systems showed mean deviations < 1 mm, only three demonstrated <0.6 mm accuracy (except for Heges scanner). These results suggest that professional and mobile-based scanners can provide clinically acceptable facial data for educational and preliminary digital workflow applications, though further validation under clinical conditions is required. This study provides quantitative evidence on the accuracy and repeatability of commonly available extraoral 3D facial scanning systems under controlled laboratory conditions. The results indicate that both professional-grade and mobile-based scanners can reproduce facial morphology with clinically acceptable deviations, particularly in flat and stable regions such as the forehead and chin. Although only three systems achieved mean trueness below 0.6 mm, all demonstrated errors within 1 mm, sufficient for diagnostic visualization, digital smile design, and preliminary virtual patient modeling. These findings support the safe and cost-effective adoption of extraoral facial scanning in dental education and treatment planning, while emphasizing the need for further validation in real clinical environments where motion, lighting, and soft-tissue variability may affect accuracy.

Background: This study aims to compare treatment time and patient satisfaction between digital and conventional impression techniques in single-tooth implant prosthetics. Materials and Methods: A controlled study was conducted on 22 patients with single-tooth loss in the posterior arch who underwent implant replacement. Impressions were taken using both conventional techniques (polyvinyl siloxane) and digital methods (3Shape Trios 3 Move scanner). Results: The digital impression technique significantly reduced treatment time compared to the conventional method. The total procedure time and individual steps in the digital process were notably shorter than those in the conventional process (p < 0.001). Patients who underwent digital impressions reported not only significantly higher satisfaction and comfort levels but also less pain, unpleasant taste, and level of nausea (p < 0.001). Conclusions: Digital impressions can be superior in reducing treatment time and improving patient satisfaction compared to conventional methods, highlighting their advantages in single-tooth implant prosthetics. However, further research, involving different digital systems and clinical evaluations, is required to fully validate these advantages.

Introduction: We aimed to compare the accuracy of digital and conventional impression techniques in full-arch edentulous implant patients and to evaluate the impact of using an auxiliary geometry part (AGP). Methods: A mandibular edentulous stone cast with four multiunit abutment analogs was fabricated as the master cast. This cast was scanned using an industrial scanner to generate reference data. Impressions were then obtained using three techniques: intraoral scanning (IOS), IOS with an AGP (IOS-AGP), and the open-tray splinted conventional technique (OTS). The precision of the impression methods was evaluated by measuring the distance and angle between the right distal implant and the other three implants. Precision was assessed using the coefficient of variation. Results: Regarding distance assessments IOS-AGP group showed a statistically significant lower coefficient of variation in comparison with IOS and OTS. Regarding angle assessments, we found statistically nonsignificant differences among IOS, OTS, and IOS-AGP groups. Conclusion: Full-arch digital implant impressions using IOS-AGP provided superior accuracy for distance measurement compared to conventional impressions.

Objective: This study aimed to evaluate and compare the clinical performance of ceramic veneers cemented with two different cements, Variolink Esthetic LC (Ivoclar, Schaan, Liechtenstein) and Vitique (DMG, Hamburg, Germany), over a three-month period. Methods: Sixty patients (49 females and 11 males; age range = 18-45 years; mean age = 34.93 ± 7.48 years) requiring ceramic veneer restorations on anterior teeth were divided into two groups based on the cement used: Variolink (n = 30) and Vitique (n = 30). All the veneers were fabricated using lithium disilicate with a thickness between 0.5 and 0.7 mm. Clinical evaluations were performed at one week (T1) and three months (T2) after placement using the modified plaque index (mPLI), modified bleeding index (mBI), color match between restored and adjacent teeth using spectrophotometry (VITA Easyshade V, VITA Zahnfabrik, Bad Säckingen, Germany), and the modified United States Public Health Service (USPHS) criteria. Results: At T1, 91.7% (n = 55) of cases showed no plaque (score 0), which improved to 96.7% (n = 58) at T2. Regarding the bleeding index, 95.0% of patients (n = 57) showed no bleeding (score 0) at T1, which improved to 98.3% (n = 59) at T2. The color difference (ΔE) between the restored and adjacent teeth at T1 was 2.13 ± 2.17 for Variolink and 1.91 ± 1.79 for Vitique (p = 0.673), with similar values at T2 (2.30 ± 1.42 and 2.22 ± 1.54, respectively; p = 0.751). Central incisors showed significantly better color match (ΔE = 2.10 ± 1.92) than lateral incisors (ΔE = 2.62 ± 2.08) at T2 (p = 0.04). Regarding marginal adaptation, most restorations showed perfect adaptation or minor discrepancies. Marginal discoloration was minimal. Conclusion: This study demonstrated the excellent short-term performance of Variolink and Vitique. Both cement systems provided good marginal adaptation, color stability, and biocompatibility, with no significant differences between them.

Đặt vấn đề: Vách xương và mô nướu mặt ngoài vùng răng trước hàm trên là yếu tố quan trọng quyết định đến thẩm mỹ và thành công của điều trị implant. Mục tiêu: Xác định khoảng cách từ đường nối men – xê măng đến mào xương ổ mặt ngoài (CEJ – AC) và khoảng cách từ viền nướu mặt ngoài đến mào xương mặt ngoài (GM – AC) của nhóm răng trước hàm trên, vị trí chân răng trước hàm trên trong xương ổ răng, bề dày mô nướu mặt ngoài vùng răng trước hàm trên và đánh giá tương quan giữa vách xương đối với mô nướu mặt ngoài vùng răng trước hàm trên. Đối tượng và phương pháp nghiên cứu: Nghiên cứu cắt ngang mô tả, phân tích trên 100 hình ảnh CBCT thoả các tiêu chí chọn mẫu. Các răng trước hàm trên được đo đạc trong mặt phẳng đứng dọc: bề dày vách xương mặt ngoài tại các vị trí cách mào xương 1mm (điểm A), 3mm (điểm B), 5mm (điểm C) và tại chóp răng; bề dày mô nướu tại điểm A; khoảng cách CEJ – AC và GM – AC; phân loại vị trí chân răng theo Kan 2011. Kết quả: Khoảng cách CEJ – AC tăng dần từ răng cửa giữa (1,92 ± 0,86) đến răng nanh (2,40 ± 1,79), ngược lại, khoảng cách GM – AC giảm dần từ răng cửa giữa (3,10 ± 0,69) đến răng nanh (2,96 ± 1,48). Vị trí các chân răng trước trong mặt đứng dọc đa số thuộc loại I (94,85%) theo phân loại Kan 2011. Mô nướu của răng cửa giữa là dày nhất (0,76 ± 0,19), tiếp đến là răng cửa bên (0,59 ± 0,19) và mỏng nhất là răng nanh (0,53 ± 0,19). Tương quan giữa bề dày vách xương và bề dày mô nướu mặt ngoài (ghi nhận tại điểm A) cho thấy có mối tương quan nghịch, mức độ tương quan yếu, |R|<0,3, (p < 0,05). Kết luận: Đa số bệnh nhân có kiểu hình mô nướu mặt ngoài mỏng, có mối tương quan nghịch mức độ yếu giữa bề dày vách xương và mô nướu mặt ngoài, và chân răng dựa vào vách xương mặt ngoài (loại I theo Kan).