Dentistry Journal最新文献

Background: Digital technologies, particularly CAD/CAM workflows, have transformed implant prosthodontics by improving the accuracy and efficiency of impression procedures, facilitating clinician-laboratory communication, and supporting the preservation of peri-implant tissues. Objective: To compare the three-dimensional accuracy (trueness) and passive fit of five conventional and digital impression techniques for fixed prostheses supported by two implants. Methods: An in vitro experimental study was conducted using a partially edentulous maxillary model with two implants supporting a three-unit zirconia bridge. Five impression workflows were evaluated: conventional techniques (open-tray and closed-tray, splinted and non-splinted) and digital impressions using plastic and titanium scan bodies. Three-dimensional accuracy was assessed by digital superimposition analysis, and passive fit was evaluated by marginal gap measurements using digital microscopy and ImageJ (version 1.54r) software. Statistical analyses were performed using exploratory ANOVA with Welch's correction and Games-Howell post hoc tests (p < 0.05), complemented by effect size analysis. Results: Three-dimensional superimposition analysis revealed that digital impression workflows and the splinted conventional open-tray technique exhibited the highest trueness, with minimal spatial deviations relative to the reference model, together with the lowest marginal gap values (<1 µm). The non-splinted open-tray technique presented higher discrepancies (7.37 ± 0.94 µm), although all techniques remained within clinically acceptable tolerance ranges (60-150 µm). Conclusions: Under controlled in vitro conditions, both digital impression techniques and conventional splinted protocols achieve high three-dimensional accuracy and clinically acceptable passive fit for multi-implant-supported fixed prostheses. Digital workflows represent a predictable and efficient alternative, while conventional splinted impressions remain a reliable option depending on clinical and technological considerations.

(1) Background/Objectives: Gap formation contributes to the clinical failure of partial crowns. Therefore, it was analyzed at the interfaces between restoration, luting material, and tooth in partial crowns made of lithium disilicate ceramic (LS2) and nanohybrid composite (RBC) after thermomechanical loading (TCML) using optical coherence tomography (OCT). (2) Materials and Methods: Sixteen human mandibular molars were restored with CAD/CAM partial crowns made of LS2 (IPS e.max^® CAD) or RBC (Tetric^® CAD) using adhesive cementation (Variolink^® Esthetic DC). The restorations were imaged by OCT (1550 nm, 28 kHz) at t0 = 24 h, t1 = 90 days of water, t2 = after TCML with 480,000 loading cycles, and t3 = TCML with 1,200,000 loading cycles. Gap lengths (%) at interface 1 (partial crown-luting material) and interface 2 (luting material-enamel/dentin) were quantified. Groupwise and pairwise comparison of OCT parameters was conducted using the Mann-Whitney U, Friedman, and Conover-Iman tests with Bonferroni correction (α = 0.05). (3) Results: At interface 1, LS2 showed a larger median gap length than RBC (ceramic = 48.4%; composite = 5.2%, p < 0.01). At interface 2, the largest median gap length for LS2 was measured at the dentin (ceramic = 59.7%; composite = 52.5%), while for RBC, the enamel was more affected (ceramic = 26.2%; composite = 36.9%). (4) Conclusions: OCT enables reliable gap detection in partial crowns under functional loading and is therefore suitable for monitoring adhesive interface integrity. Under in vitro conditions, both materials demonstrated stable adhesive performance without debonding, while material-dependent differences in gap formation and distribution were observed.

Background/Objectives: Pre-eruptive intracoronal resorption (PEIR) in impacted or unerupted teeth often remains undiagnosed. The aim of this study was to investigate the prevalence of PEIR with the aid of cone beam computed tomography (CBCT) and propose a new three-dimensional (3D) classification for the analysis of the lesions. Methods: A total of 164 unerupted teeth diagnosed in CBCT scans, derived from an equivalent number of patients, were examined for the presence of PEIR, tooth type, angulation and position. A novel 3D classification system was proposed and all PEIR lesions were further classified. The classification system was used to stage PEIR lesions according to their extend from the enamel level apically, the circumferential spread and their proximity to the pulp chamber. Descriptive statistics were used to assess the prevalence and type of resorption. The association between PEIR, demographics, tooth type, position and angulation were studied. The estimation of the multivariate relationship between PEIR, patient's demographics and tooth characteristics was conducted with the multiple binary logistic regression model. Results: The prevalence of PEIR was 33.5%, affecting mostly maxillary canines, and maxillary and mandibular molars. The prevalence of PEIR in ages over 45 years was significantly higher (p < 0.001). The presence of PEIR was significantly associated with buccal position (p = 0.002) and buccal angulation (p = 0.016) of the tooth. Conclusions: Due to the high prevalence of PEIR, CBCT may improve detection and 3D characterization when imaging is already clinically indicated, and influence treatment planning in selected cases.

Background/Objectives: Accurate three-dimensional (3D) facial scanning is increasingly important in digital dentistry for diagnosis, treatment planning, and virtual patient creation. Multiple facial scanning technologies are available; however, their metric reliability varies depending on acquisition principles and anatomical orientation. This study aimed to evaluate the trueness, orientation-dependent performance (vertical midline versus horizontal facial measurements), and scanning time of four facial scanning technologies using calibrated manual anthropometry as the reference standard. Methods: Thirty dentate adult participants received adhesive fiducial markers on five predefined facial landmarks. Four linear facial distances were measured clinically using a digital caliper and compared with corresponding measurements obtained from standardized 3D facial scans. Digital measurements were extracted following uniform metric normalization. Inter-examiner reliability, measurement trueness, orientation-related differences, and scanning time were analyzed. Results: Inter-examiner reliability was excellent for both clinical and digital measurements (ICC > 0.93). All facial scanning technologies significantly overestimated manual distances (p < 0.001). The structured-light scanning system showed the smallest deviations (typically <1 mm) and the highest overall accuracy, followed by the depth-fusion system, while photogrammetry-based and NeRF-based approaches demonstrated larger errors, frequently exceeding 2-3 mm. Horizontal facial distances consistently showed greater deviations than vertical midline measurements across all systems. Scanning time differed significantly between technologies, with passive image-based approaches being the fastest and NeRF-based acquisition requiring the longest capture time. Conclusions: Active structured-light facial scanning demonstrated the highest trueness for linear facial anthropometry, whereas passive photogrammetry and NeRF-based approaches showed lower metric trueness and are currently more suitable for educational applications.

Background/Objectives: Bulk-fill (BF) resin-based composites (RBCs) have become increasingly popular due to their efficient placement. However, there is a lack of comprehensive performance comparisons among commercially available BF RBCs. In standardized curing conditions, this study aimed to compare the mechanical performance, water sorption and solubility, surface roughness, and color stability of commercially available BF RBCs with different consistencies (flowable and packable). Methods: Ten BF RBCs, along with a conventional RBC (control), were evaluated. Flexural strength and elastic modulus were measured using a three-point bending test. Water sorption and solubility were assessed after 28-day water storage. Color (ΔE₀₀) and surface roughness (ΔRa) changes were measured after 28-day immersion in water, Pepsi, or coffee. One-way ANOVA and Tukey's tests analyzed the data. Results: 3M Flow, Shofu Bulk, and Ivoclar Flow revealed lower strength (p < 0.001) compared to 3M Bulk (132.17 ± 12.54 MPa) and the control (124.56 ± 15.60 MPa). Shofu Bulk (24.68 ± 12.55 µg/mm³) and Ivoclar Flow (27.11 ± 6.27 µg/mm³) were the least affected by water sorption. While Shofu Bulk (13.98 ± 11.39 µg/mm³), Ivoclar Flow (20.28 ± 6.64 µg/mm³), and SDR (20.84 ± 9.74 µg/mm³) exhibited the lowest solubility (p < 0.01). After water and Pepsi immersion, FGM Bulk showed a significant color change compared to 3M Bulk and Ivoclar Bulk (p < 0.05). Following coffee immersion, Shofu Bulk (17.38 ± 1.82) revealed significant color changes (p < 0.001). Increased surface roughness was observed in 3M Bulk and Ivoclar Bulk after water immersion, Shofu Bulk after Pepsi immersion, and FGM Bulk after coffee immersion. Conclusions: BF RBCs exhibit notable variability in their intrinsic properties. 3M Bulk and Control showed the highest strength, while Shofu Bulk had significant color changes.

Background: Language serves as a significant barrier to accessing dental services. Dental treatment options are often complex and involve terminology that is unfamiliar to most patients. In some cases, dental students may use technical terms that patients do not understand, leading to confusion and misunderstandings. Therefore, this study aimed to assess the language barriers faced by dental students and patients in Riyadh, Saudi Arabia. Methods: A mixed-methods research design was employed to evaluate language barriers between dental students and patients, as it provides an in-depth understanding and generates information beyond mere numerical data. The study was conducted from 1 September 2024, to 30 August 2025, in Riyadh, Saudi Arabia. Data collection primarily involved conducting interviews with focus group members using a comprehensive topic guide consisting of predetermined questions. Results: Forty dental students and forty patients agreed to participate in this study. The students encountered significant difficulty explaining terms such as crown lengthening (72.5%) and periodontitis (67.5%), while patients reported limited understanding of interim removable dental prosthesis (65%) and fixed dental prosthesis (60%). Comparative analysis indicated that sixth-year students reported significantly more difficulty explaining "crown lengthening" and "prefabricated post and core" compared to fifth-year students. It was also observed that patients' educational level had a significant impact on their understanding of terms such as "interim dental prosthesis" and "removable dental prosthesis." Qualitative analysis revealed patients' partial understanding or misinterpretation of dental terminologies. Conclusions: Our findings indicate that language discordance, even among speakers of the same native language, can hinder effective communication, particularly when technical vocabulary is involved. Students may struggle to explain procedures in a manner that patients can easily understand. This can lead to incomplete patient comprehension and potential non-compliance with treatment recommendations. Hence, we recommend incorporating Arabic dental terminologies alongside English into the curriculum, developing bilingual glossaries, and using visual aids when communicating with patients.

Cone-beam computed tomography (CBCT) is widely utilized in endodontics for evaluating root canal shaping outcomes, offering critical three-dimensional imaging capabilities. This study aims to assess the differences in apical and root canal preparation across various instrumentation techniques using CBCT. A systematic search of the Medline database (via PubMed) and Web of Science was performed up to 12 April 2025, yielding a total of 70 studies, with 45 full-text articles assessed for eligibility; 28 were included in the review. Studies showed great heterogeneity in experimental design, anatomical variables, and outcome measurements. The results indicate that rotary instruments, such as ProTaper Next^® and XP-Endo Shaper^®, were reported more frequently or showed favorable shaping trends in individual studies. Although rotary systems often appeared advantageous, conclusions were limited by study design variability and a lack of correlation with clinical outcomes. The evidence highlights the need for standardized methodologies and further research, especially on manual techniques. CBCT remains a valuable research tool despite inherent spatial resolution limitations.

Background: Haptic virtual simulation (HVS) has emerged as a promising tool in dental education, yet evidence comparing its performance to conventional preclinical training remains limited. Establishing its effectiveness is essential to support its integration into competency-based curricula. Objective: The aim of this study was to compare Class V cavity preparations performed using conventional training on extracted teeth with those performed using a haptic virtual simulator, evaluating preparation time and cavity volume. Methods: Sixty-one extracted human molars were digitized using cone-beam computed tomography (CBCT) to generate corresponding virtual replicas. A calibrated operator prepared 122 standardized Class V cavities (61 real and 61 virtual). The simulator automatically recorded preparation time and cavity volume. For natural teeth, cavity volume was calculated by digital superimposition of pre- and post-operative STL models using Blender. Paired means were compared using Student's t-test (α = 0.05). Results: Preparation time was significantly shorter when using HVS compared with the conventional method (p < 0.001). Virtual preparations resulted in slightly larger cavity volumes than real preparations, with a statistically significant yet clinically small difference (p = 0.047). Conclusions: Haptic virtual simulation enables more time-efficient Class V cavity preparation while producing cavity volumes comparable to those obtained through conventional training. These findings support the implementation of haptic simulators as a valid and effective complement for preclinical skill acquisition in operative dentistry.

Objectives: To evaluate the clinical effectiveness and safety of natural products compared with chlorhexidine (CHX) as adjuncts to non-surgical periodontal therapy (NSPT) in patients with periodontitis. Materials and Methods: This systematic review was conducted in accordance with the PRISMA 2020 guidelines and registered in PROSPERO (CRD420251133219). Electronic searches of PubMed, Scopus, and Web of Science were performed to identify randomized controlled trials (RCTs) published between 2020 and 2025. Eligible studies included adult patients with periodontitis treated with NSPT, comparing CHX-based products with natural formulations (mouthwashes, gels, irrigants, or dentifrices). Data extraction included product type, concentration, mode of application, follow-up duration, and primary periodontal outcomes. Study quality was assessed using the NIH Quality Assessment Tool. Results: Thirteen randomized controlled clinical trials met the inclusion criteria. Natural products such as Curcuma longa, Morus alba, Spirulina platensis, Propolis, Triphala, and Lycium barbarum demonstrated improvements in clinical attachment level (CAL) and probing pocket depth (PPD) comparable to those obtained with CHX, along with significant reductions in bleeding on probing (BoP) and plaque index (PI). Probiotic- and ozone-based treatments also showed favorable clinical outcomes, with faster healing and fewer adverse effects, such as tooth staining and taste alteration. Follow-up periods ranged from 14 days to 3 months. Conclusions: Natural products appear to be safe and effective alternatives to CHX when used as adjuncts to non-surgical periodontal therapy, providing comparable clinical benefits with a lower incidence of side effects. Nevertheless, further large-scale, long-term randomized trials are needed to standardize formulations and concentrations and to confirm the durability of these clinical effects.

Background/Objectives: Dental implants are a preferred solution for missing teeth, but peri-implantitis remains a major challenge in implant dentistry. This narrative review provides an overview of the therapeutic interventions for peri-implantitis based on the current literature and illustrates a new clinical approach using novel magnesium membrane through three case presentations. Methods: A comprehensive literature search on peri-implantitis management was conducted, with emphasis on current clinical practice guidelines. In addition, three clinical cases were presented to demonstrate the use of a fully resorbable magnesium membrane in combination with a bovine xenograft with hyaluronate. Results: The narrative review identified and summarized a wide range of non-surgical and surgical therapeutic strategies for treatment of peri-implantitis. Additionally, three case reports with novel magnesium membrane highlighted distinct clinical scenarios: (1) bone defect reconstruction without implant removal, (2) reconstruction following implant removal, and (3) a minimally invasive shield technique performed without removal of the implant or crown. All cases demonstrated favorable clinical outcomes following the novel biomaterial approach. Conclusions: The combination of a resorbable magnesium membrane with bovine xenograft with hyaluronate represents a promising therapeutic strategy for treatment of peri-implantitis. This approach may improve clinical outcomes and potentially set new standards in implant dentistry. Further studies with larger cohorts and control groups are required to confirm these preliminary findings.