Background: Nanoparticles are used for preventing oral diseases, fabricating prostheses, and for dental implantation. They are also used for delivering drugs for oral application, preventing and treating oral diseases, includeing oral cancer, and maintaining the health of oral tissues to a greater extent.

Purpose: To systemically analyze the thermal behavior of nanoparticles-incorporated polycarbonate resin.

Materials and Methods. Online databases like Google Scholar, PubMed, PubMed Central, Scopus, Cochrane, and Science Direct were searched using the key terms polycarbonate resin OR nanoparticles, polycarbonate resin AND nanoparticles, and polycarbonate resin NOT nanoparticles from 1^st January 2010 to 31 ^st December 2024. The inclusion criteria were in vitro studies with full-text articles in the English language, and the exclusion criteria were clinical research, randomized clinical trials, animal studies, articles with only abstracts available, and literature reviews.

Results. After applying the inclusion and exclusion criteria, 22 original articles were thoroughly analyzed, and 11 studies were selected for a systematic review. Thermal properties like glass transition temperature and decomposition of polycarbonate and nanoparticle composites were affected by nanoparticles such as Silica, Titanium, Zinc, and Zirconium at various percentages.

Conclusion. Thermal properties like glass transition temperature, light transmission, and decomposition rate decreased, while the storage modulus and flame retardancy increased with the increasing percentage of Silica, Titanium, Zinc, and Zirconium nanoparticles.

AIM

This in vitro study aimed to assess the influence of clinical experience on two key aspects of the digital chairside workflow: intraoral scanning efficiency and the morphological accuracy of CAD-designed prosthetic crowns, by comparing three operator groups with different levels of experience.

MATERIALS AND METHODS

Thirty dental operators were divided into three homogeneous groups: ten sixth-year dental students (S), ten general practitioners (O), and ten prosthodontic specialists with advanced clinical expertise (P). The reference model featured the lower left second premolar, prepared with a horizontal finish line and supragingival margin (Fig. 1). Each operator performed three digital scans of the model following a standardized scanning strategy (Fig. 2), and completed a CAD design of a crown on the prepared tooth (Fig. 3). Digital impressions were acquired using the Primescan intraoral scanner (Dentsply Sirona), and designs were created with CEREC 5.3 software. Scan time was manually measured with a stopwatch. Three expert prosthodontists independently assessed the CAD crown quality using a Visual Analogue Scale (VAS).

RESULTS

Mean scan times were group S = 231.80 s; group O = 174.40 s; group P = 70.00 s. Mean VAS scores were S = 7.60; O = 9.00; P = 9.60 (Table 1). The Shapiro–Wilk test indicated a non-normal distribution (p > 0.005). The Kruskal–Wallis test revealed significant differences between students and prosthodontists in both scan time (p = 0.002) and CAD quality (p = 0.012) (Table 2). No significant differences emerged between students and general practitioners, nor between practitioners and prosthodontists.

CONCLUSION

Despite all operators producing clinically acceptable results, a positive correlation was found between clinical experience and performance in terms of scanning efficiency and CAD design quality.

Introduction:

Immediate implant placement provides clear clinical benefits, including reduced treatment time and preservation of alveolar bone structure [1,2]. Despite these advantages, achieving predictable and esthetic soft-tissue outcomes remains a consistent challenge. Customized healing abutments (CHAs), fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM), are intended to better support peri-implant soft tissue compared to standard stock components [3,4]. Although initial findings are encouraging, the available evidence remains limited and inconsistent across studies [2]. This systematic review aims to assess soft-tissue esthetic outcomes associated with CAD/CAM-fabricated CHAs following immediate implant placement.

Methods:

A systematic search was conducted in PubMed, Springer Nature Link, and Wiley Online Library following PRISMA guidelines. Studies published in English within the past five years assessing soft tissue esthetic outcomes of CAD/CAM CHAs after immediate implant placement were included. Out of 145 articles screened, 5 met the inclusion criteria.

Results:

All five studies reported improved peri-implant soft tissue esthetics with CAD/CAM CHAs. High Pink Esthetic scores were consistently observed, with Elgendi et al. reporting a mean score of 9.64 ± 0.50 and full papilla fill at 12 months using PEEK CHAs [5]. Increases in mucosal thickness and keratinized tissue width were statistically significant in multiple studies (p < 0.05) [2,3]. Long-term data from Akin and Chapple demonstrated preserved emergence profiles and no mucosal recession over 8 years in 115 posterior implants, indicating durable soft tissue outcomes. Buccal volume loss was significantly reduced (–4.76% ± 5.29%, p = 0.043) and overall dimensional stability was maintained, with minimal soft tissue changes reported across studies [1,3,6]. While sample sizes and methodologies varied, all studies demonstrated favorable esthetic outcomes with CHAs compared to conventional approaches.

Conclusion:

CAD/CAM-fabricated CHAs improve soft tissue esthetics in immediate implant placement by preserving volume, enhancing contours, and maintaining emergence profiles. Despite promising results, further standardized, long-term clinical trials are needed to validate these outcomes.

ABSTRACT:
Digital technologies have become an integral part of daily life, offering increasingly sophisticated tools across many professional sectors. With the growing integration of artificial intelligence and digital realities (AR, VR, MR), even specialized fields such as dentistry are beginning to benefit from these advancements. In particular, augmented reality now allows for the simultaneous visualization of intraoperative information and the remote sharing of clinical procedures.

AIM:
This study aimed to evaluate dental students’ perception and appreciation of a 3D Augmented Reality system (Falko) used in an educational context, comparing 3D and 2D visualizations. The null hypothesis stated that no statistically significant difference would be found between the two modalities.

METHODS:
During a standard clinical teaching session, thirty dental students from various academic years were divided into two groups. One group used the 3D system via head-mounted displays and VR glasses, while the other used 2D displays via smartphones or clinic monitors. The session was delivered both in the clinical environment and remotely. At the end of the session, participants completed a questionnaire via Google Forms, consisting of six VAS-scale questions evaluating key aspects of the system’s educational usefulness.

RESULTS:
Students reported a highly positive experience, with increased engagement and attention noted across both groups. Due to the non-normal distribution , the Student’s t-test was not applicable. Instead, the Mann–Whitney test revealed a statistically significant difference for the 3D group.

CONCLUSION:
The null hypothesis was rejected, confirming that the 3D visualization mode was significantly more appreciated than the 2D one. Despite the encouraging findings, the innovative nature of this study and the limited sample size; further research with a larger sample size is needed to validate these results.

Aim:
This study aimed to evaluate the marginal adaptation of 3D printed crowns with either horizontal or vertical margin preparations, scanned with an IOS (3Shape), showing an accuracy of 5 µm, at standardized environmental conditions.

Methods:
Two maxillary first premolar abutments were designed using CAD software, one with a horizontal preparation (Ho) and the other with a vertical preparation (Ve). Both abutments had a 5 degree angle of TOC (Total occlusal convergence); they were 3D printed in resin, and then mounted on a reference typodont. Ten crowns were fabricated for each preparation geometry using the DFAB 3D printer (DFAB CHAIRSIDE, Thiene, Italy). Cementation was simulated with polyether impression material, and then the crowns were scanned with an industrial metrological device (Atos Core 80; GOM GmbH, Germany). Finally, the scans were analyzed using a dedicated software (Geomagic Control X, Raindrop Inc., USA) to assess the marginal fit. Descriptive statistics (95% confidence interval) were calculated, and an independent samples t-test was performed at a significance level of α = 0.05 to compare differences between groups.

Results:
Mean marginal fit values for both preparation geometries were below the clinically acceptable threshold of 120 µm, with Ho at 76.83 µm and Ve at 84.37 µm. No statistically significant difference was found between the two groups (Ho p = 0.58; Ve p = 0.83).

Conclusions:
Nanocomposite crowns fabricated via 3D printing showed mean marginal discrepancies within clinically acceptable limits for both vertical and horizontal preparation geometries, with no significant difference between the two.

Aim
This prospective clinical protocol aimed to assess the four-year survival and success rates of single implant-supported monolithic zirconia crowns, fabricated through a fully digital workflow, in the prosthetic rehabilitation of patients presenting with unilateral or bilateral congenital absence of the maxillary lateral incisors. The study also analyzed biological and technical variables affecting clinical outcomes, including patient-reported satisfaction.

Methods
A total of 22 patients with mono- or bilateral agenesis of the maxillary lateral incisors were enrolled, receiving 30 narrow-diameter implants. Corresponding screw-retained monolithic cubiczirconia (5Y-TZP) crowns with internal connections were digitally manufactured and delivered. Clinical performance was objectively evaluated using the Functional Implant Prosthodontic Score (FIPS), while subjective patient satisfaction was measured using a Visual Analog Scale (VAS). Survival and success analyses were performed using descriptive statistics and the Kaplan–Meier method.

Results
At the four-year follow-up, the mean FIPS (Functional Implant Prosthodontic Score) was 9.2, and the mean VAS (Visual Analog Scale) score for patient satisfaction was 8.7. Cumulative survival and success rates were 100% and 93.3%, respectively, according to Kaplan–Meier estimates.

Conclusion
The use of a fully digital implant–prosthetic protocol represents a reliable and effective short-term solution for the functional and esthetic rehabilitation of maxillary lateral incisor agenesis. Nonetheless, further longitudinal studies are warranted to confirm the long-term predictability of this approach.

Aim

Nowadays, digital technologies have deeply changed prosthetic paradigms and dentists are increasingly providing dental treatments with a full digital workflow. This study aimed to assess whether edentulous patients, who were trained by a dental hygienist about hygienic maintenance, show a different plaque retention at the intaglio surface of full dentures (FD) compared to untrained patients. Additionally, the study aimed to introduce a new digital index for the denture hygiene evaluation.

Materials and Methods

Thirty edentulous patients were enrolled by dentists of the Scientific Unit of Digital Dentistry, directed by Prof. Fernando Zarone, and were randomly divided into two groups: trained (TG) or control group (CG). TG received practical demonstrations on home hygiene procedures, while CG received only written instructions following the American College of Prosthodontists’ guidelines. At baseline and 1 year follow-up, a plaque detector was used in the FD intaglio, then a photographic documentation and an intraoral scan of the FD were performed. Scan data was analyzed by MeshLab software to calculate the "Zarone Index," detecting the percentage of denture surface covered with plaque.

Results

Power analysis confirmed the study's statistical validity. Normality and homogeneity of variance tests were performed. The Welch test showed statistically significant differences (p<0.001) between the "Trained Baseline" and "Trained Follow-up" groups, as well as between the "Trained Follow-up" and "Control Follow-up" groups. No significant differences between the "Control Follow-up" and "Control Baseline" groups were evidenced.

Conclusion

Trained patients demonstrated both statistically and clinically significant improvements in prosthesis care and home hygiene. These findings highlight the importance of a collaborative approach involving dentist, hygienist and patient in order to improve the treatment outcomes. These preliminary results will be extended with a longer-term follow-up.

Introduction: Minimally invasive dentistry prioritizes preserving tooth structure while restoring function and esthetics. For posterior restorations, choosing among various ceramic and hybrid ceramic materials presents a significant dilemma. The present work discusses the critical factors influencing the selection of these indirect materials, highlighting their properties, indications, and the challenges in optimizing clinical outcomes.

Methods: The material classes considered include feldspathic porcelain, leucite-reinforced ceramics, lithium disilicate, zirconia (monolithic and layered), and resin–ceramic hybrid materials. Evaluation criteria encompass mechanical properties (flexural strength, fracture toughness, wear resistance), esthetics, bondability, biocompatibility, and their ability to facilitate conservative tooth preparation. Clinical scenarios and patient-specific factors like occlusal load, esthetic demands, and opposing dentition are also addressed.

Results: For posterior mini-invasive restorations, lithium disilicate is a common choice, offering excellent esthetics and good mechanical properties for inlays, onlays, and crowns. Zirconia, particularly in monolithic forms, is preferred for high-occlusal-load situations due to its superior strength, though esthetics may vary with opacity. Newer translucent zirconias balance esthetics and strength. Resin–ceramic hybrid materials combine polymer resilience with ceramic wear resistance, offering shock absorption and ease of repair for specific minimally invasive applications. The dilemma often involves balancing strength, esthetics, and conservative preparation, as material properties directly influence required preparation dimensions. Patient factors like bruxism or limited interocclusal space further complicate the decision.

Conclusions: Selecting indirect ceramic or hybrid ceramic materials for posterior minimally invasive restorations in prosthodontics is a complex decision. While lithium disilicate and zirconia offer robust options for strength and esthetics, resin–ceramic hybrids provide unique advantages. The ultimate choice hinges on a thorough clinical assessment, aiming to resolve this material dilemma for optimal long-term success of conservative restorations.

Background

The precise orchestration of crown lengthening and veneers in the esthetic zone remains a cardinal challenge in multidisciplinary oral rehabilitation. Traditional empiricism-based approaches inherently carry risks of unpredictable esthetic outcomes due to reliance on subjective estimation. To address this, a digital workflow integrating DTX Studio and Exocad was developed, enabling closed-loop precision control from diagnosis to prosthetic design.

Integration with Digital Workflow Elements

1. Multimodal Data-Driven Assessment

CBCT, intraoral scans, and facial topography were integrated to construct a patient-specific digital model for comprehensive assessment.

2. Virtual Planning for Biological Width Preservation

Exocad’s morphology simulation reverse-engineers ideal gingival positions, quantifying gingival trimming with 0.1 mm accuracy. For example, if a veneer margin requires placement 1 mm apical to the existing gingiva, the digital workflow calculates a 3 mm total adjustment (1 mm gingival recontouring + 2 mm biological width), guided by the dual-positioning guide plate.

3. Surgical Guidance via 3D-Printed Precision

The dual-positioning guide plate, designed in DTX Studio using CBCT-derived bone segmentation, enforces precise bone reduction trajectories. Its primary cortical registration and secondary soft tissue matching ensure the surgical margin is maintained at the calculated 2 mm from the bone, minimizing risks of biological width violation

4. Post-Surgical Prosthetic Optimization

iTero scans post-healing capture final gingival topography, allowing Exocad to refine veneer emergence profiles, contributing to the 40% treatment duration reduction by eliminating iterative adjustments for biological width-related complications.

Result：

Surgical error was minimized to <0.3 mm (70% reduction vs. traditional methods)， as validated by the digital workflow’s closed-loop control from CBCT segmentation to prosthetic design. Preoperative smile visualization via the multimodal model enhances patient understanding of how biological width preservation influences final pink–white esthetic harmony.

Conclusion:

The DTX-Exocad platform revolutionizes traditional workflows through data-driven decision-making and real-time workflow control, delivering quantifiable precision for complex rehabilitations. This technological convergence epitomizes evidence-based digital dentistry, where seamless workflows redefine clinical excellence.

The success of an implantological rehabilitation is determined by multiple surgical factors (implant position, implant distribution, number of implants, implant size, bone and gingival regeneration...), patients' personal factors (general health, oral hygiene, hereditary factors, previous periodontitis, smoking, bruxism...), and prosthetic factors (restorative materials and prosthesis design).

It is on this last point that we are going to focus because, despite being of vital importance, it is the least publicized and explained. Among the different points that can intervene in the design of the prosthesis, such as the emergence profiles, the spaces to facilitate hygiene, the design of the pontics, the length and shape of the transepithelial abutments... there are some that affect edentulous mandibular patients: mandibular flexion, weight of the prosthesis, impact against the antagonist, and the importance of the design of the prosthesis and the restorative material.

It is well known that there is a flexion, a deformation of the mandible when the person opens the mouth and/or protrudes, but what is not well known is the problems it causes to the prosthesis and the implants if a correct design and a good choice of the restorative material are not made. Among the most known problems are: fracture of the prosthesis, loosening of the screws, pain and/or dysfunction during opening or protrusion, peri-implant bone loss and loss of the implants.

By means of photographs, radiographs and numerous references, we will review the existing problems and provide different solutions, both in terms of design and restorative materials, to reduce the risk of prosthesis and/or implant failure in these edentulous mandibular patients.