Accuracy of the intaglio surface of 3D-printed hybrid resin-ceramic crowns, veneers and table-tops: An in vitro study.

OBJECTIVES: The present study aims to examine the influence of the build angle on the accuracy (trueness and precision) of 3D printed crowns, table-tops and veneers with a hybrid resin-ceramic material. METHODS: One crown, on table-top and one veneer were printed in five different build angles (0°, 30°, 45°, 60°, 90°) (n = 50) with the digital light processing (DLP) system (Varseo XS, Bego) using hybrid resin (Varseo Smile Crownplus A3, Bego). All printed restorations were scanned using the laboratory scanner (D2000, 3Shape) and matched onto the initial reference design in metrology software (Geomagic Control X, 3D Systems). The root mean square error (RMSE) was calculated between the scanned and reference data. The data was statistically analyzed using the Tukey multiple comparison test and Wilcoxon multiple comparison test. RESULTS: The crown group showed higher trueness at 30° (0.021 ± 0.002) and 45° (0.020 ± 0.002), and table-tops at 0° (0.015 ± 0.001) and 30° (0.014 ± 0.001) (p < 0.0001). Veneers demonstrated higher trueness at 30° (0.016 ± 0.002) (p < 0.0001). All three restoration types demonstrated the lowest trueness at a 90° build angle and portrayed deviations along the z axis. The veneer and table-top groups showed the lowest precision at 90° (veneers: 0.021 ± 0.008; table-tops: 0.013 ± 0.003). The crown group portrayed the lowest precision at 45° (0.017 ± 0.005) (p < 0.0001). CONCLUSION: The build angle of DLP-printed hybrid resin-ceramic restorations influences their accuracy. CLINICAL SIGNIFICANCE: Considering the build angle is important to achieve a better accuracy of 3D-printed resin-ceramic hybrid restorations. This may help predict or avoid the interference points between a restoration and a die and minimize the clinical adjustments.

Comparative analysis of xenogeneic collagen matrix and autogenous subepithelial connective tissue graft to increase soft tissue volume around dental implants: a systematic review and meta-analysis.

OBJECTIVE: The gold standard for a soft tissue augmentation around implants is a subepithelial connective tissue graft (CTG), but the xenogeneic collagen matrices (XCM) started to be used as an alternative. This systematic review aimed to assess the effectiveness XCM in comparison to CTG for the increasing the thickness of the soft tissue around implants. DATA: All studies included at least two parallel groups comparing the use of CTG and XCM with a minimum follow-up of 3 months. As the primary outcome, the amount of soft tissue thickness gain after soft tissue augmentation with XCM or CTG was assessed. Secondary outcomes were clinical and patient-related outcomes; evaluation of aesthetic outcomes, patient-reported outcomes measures (PROMs) and complications. Eligible studies were selected based on the inclusion criteria. Meta-analysis was applied whenever possible. The quality of the evidence of studies including in meta-analysis was assessed using the GRADE approach. SOURCE: A systematic literature search up to January 2022 was conducted using the following electronic databases: PubMed (MEDLINE), Scopus, Cochrane Library, LILACS, eLIBRARY.RU. Unpublished researches, the gray literature, nonprofit reports, government studies and other materials were reviewed electronically using an EASY search. An additional manual search was carried out in November 2022. STUDY SELECTION: Of the 1376 articles from the initial search, 8 randomized controlled trials (RCTs) (306 patients and 325 implants) were included in this systematic review, and 7 studies were part of the meta-analysis. Meta-analysis revealed that XCM is less effective than the CTG in increasing soft tissue thickness around dental implants. However, XCM also provides soft tissue thickness gain and can be recommended for use in various clinical situations. CLINICAL SIGNIFICANCE: Previous systematic reviews and meta-analyses have shown that autologous grafts are more effective than collagen matrices in increasing soft tissue thickness, however, the latter can be used as an alternative. Studies included in previous systematic reviews varied in design, which could lead to limitations. The present systematic review and meta-analysis includes for the first time only randomized controlled clinical trials with collagen matrix of xenogeneic origin in the test group. Tight eligibility criteria were established, and the main parameter studied was soft tissue thickness. It was found that xenogeneic collagen matrix is effective for increasing soft tissue thickness around dental implants, however, the results obtained using an autogenous connective tissue graft are superior.

Delayed autotransplantation as a method of single defect treatment with sinus perforation. Case report.

Autotransplantation of teeth as an alternative to dental implantation is characterized by short healing periods, preservation of aesthetics and propriosensitivity in the area of the transplanted tooth and the possibility of its orthodontic movement. This clinical case describes a successful delayed autotransplantation of the third maxilla molar (2.8.) with the completed root formation into the socket of a previously removed tooth 1.6. with perforation in the maxillary sinus area on the right and the presence of signs of chronic inflammation. Long-term observations after 30 months demonstrate favorable healing with restoration of dentoalveolar attachment in the area of the transplanted tooth, relief of inflammatory process in the area of the maxillary sinus with restoration of the cortical plate. Key words:CBCT, tooth transplantation, dental autotansplantation, wisdom teeth.

Connective tissue graft versus xenogeneic collagen matrix for soft tissue augmentation at implant sites: a randomized-controlled clinical trial.

OBJECTIVES: The purpose of this randomized clinical trial (RCT) is to compare xenogeneic collagen matrix (XCM) versus subepithelial connective tissue graft (SCTG) to increase soft tissue thickness at implant site. MATERIALS AND METHODS: The study was a randomized, parallel-group controlled investigation. Thirty patients underwent buccal soft tissue thickness augmentation at the stage of implant placement by two different methods: SCTG (control group) and XCM (test group). Primary outcome was the amount of buccal soft tissue thickness gain, 3 months after the intervention. Secondary outcomes were the operation time, the amount of keratinized mucosa (KM), pain syndrome (PS), and patients' quality of life (QL). Histologic evaluation was also performed. RESULTS: The amount of soft tissue thickness gain was 1.55±0.11 mm in SCTG group, and 1.18±0.11mm in XCM group. The difference between the SCTG and XCM was -0.366 (-0.66 to -0.07; p=0.016). Operation time with XCM was 8.4 (3.737 to 13.06) min shorter than that with the SCTG (p=0.001). KT, PS, and QL for both groups were not statistically significantly different at any time point (p>0.05). At histological examination, the general picture in both groups was similar. No significant differences between the studied groups in most indices, except for the average and maximum formation thickness, cellularity of the basal, mitotic activity and also maximum length of rete ridges. CONCLUSION: Within limitations, this study demonstrates that the use of SCTG provides a statistically significant superior soft tissue thickness gain than XCM for soft tissue augmentation procedures around implants. CLINICAL RELEVANCE: XCM can be used as the method of choice for increasing the thickness of soft tissues.

Vitamin D and Its Role in Oral Diseases Development. Scoping Review.

Vitamin D is a fat-soluble secosteroid that plays a significant role in the whole body, including the maxillofacial region. The discovery of its receptors in many cells and organs made it possible to reveal the participation of vitamin D not only in the regulation of calcium phosphate metabolism, but also in immune processes, in providing anti-inflammatory and antimicrobial effects, slowing down cell proliferation and stimulating differentiation. In this literature review, we demonstrate the association between low vitamin D levels and the development of recurrent aphthous stomatitis, the course and response to treatment of squamous cell carcinoma of the oral cavity, the severity of periodontal diseases, and the processes of osseointegration and bone remodeling during dental implantation and guided tissue regeneration. The aim of our article was to demonstate a possible connection between vitamin D level and the oral diseases that can be presented at an oral surgery appointment, which will help clinicians to reduce the risk of early dental implant failure, ensure favorable outcomes of augmentative operations, as well as decrease the destructive effects of severe periodontitis and other conditions throug knowledge and timely lab tests and endocrinologist prescriptions.

Hard and Soft Tissue Augmentation with Single-Implant Restoration in the Esthetic Zone.

The removal of the central incisor of the upper jaw is a challenging process, since the restoration of a single implant in the esthetic zone is of great responsibility. When tooth extraction with immediate implant placement is not possible, modern protocols imply the use of the socket preservation technique. This method of preserving socket properties significantly reduces changes that occur during the healing process of the postextracted area and along with soft tissue augmentation allows to achieve a satisfying aesthetic result. The aim of present case report is to assess capabilities of socket preservation concept and application of soft tissue augmentation in the anterior maxillary region. The treatment steps of a 35-year-old woman who needed to remove tooth 11 with further dental implant placement are described. The clinical case is of interest because after socket preservation and soft tissue augmentation, an acceptable aesthetic result was not reached. However, additional soft tissue augmentation made it possible to achieve the desired result, which was stable for 7 years.

Overgrowth of soft tissues after transplantation of a connective tissue graft for the treatment of gingival recession.

The application of free connective tissue graft (CTG) is the gold standard in the treatment of gingival recession in the area of teeth and implants. The aim of this case report is to demonstrate a possible mucosal overgrowth complication in the soft tissue grafting area. A 24-year-old patient underwent the treatment of gingival recession in the tooth 2.3 region by an envelope technique using a free CTG from the hard palate region. Seven years after the surgery, a mucosal overgrowth was observed, which developed asymptomatically and did not cause any problems to the patient.

Full-Mouth Screw-Retained Implant-Supported Rehabilitation with Multiunit Abutments Using Virtual Guided Surgery and Digital Prosthetics Protocol.

Total rehabilitation is one of the most sophisticated kinds of dental implant-supported prosthetics. The usage of multiunit abutment system allows the clinician an accurate and passive fitting of screw-retained full-arch construction. In addition, it retains a condition of soft and bone tissues around prosthetic construction. The aim of this case is to demonstrate a modern approach in planning and realisation of full-mouth screw-retained dental implant prosthetics. A 59-year-old patient had an extraction of all failed teeth on upper and lower jaws with immediate 16 implant placement (8 implants on maxilla and 8 implants on mandible) using surgical template. Multiunit abutments were installed intraoperatively. Temporary constructions were fixed immediately after surgery. After 3 months of dental impressions, plaster models and their scan were prepared to make final screw-retained zirconium dioxide constructions. Reevaluation of functional and aesthetic result of the treatment was made after 12 months.

Autotransplantation of teeth as an alternative to dental implantation.

Autotransplantation of teeth is a considerable option for tooth replacement in adults who are to undergo orthodontic treatment. Being compared with dental implantation, this procedure is more preferable as a grafted tooth functions as a normal one. In this case report, we describe successful autotransplantation of the third molar with complete root formation. To provide better adaptation of the donor tooth, we used its preoperatively printed replica. The donor tooth was immediately placed to the recipient site and splinted for 28 days. Endodontic treatment was initiated 2 weeks after transplantation. Clinical and radiographic findings at 6 and 12 months of follow-up are compared with the results described in the literature.

Comparative analysis of methods to increase the amount of keratinized mucosa before stage-two surgery: a randomized controlled study.

OBJECTIVES: The aim of the present randomized controlled clinical trial was to evaluate the outcomes of the use of free gingival graft (FGG), of a collagen matrix and of vestibuloplasty to increase the amount of keratinized attached mucosa (KM) before healing abutment placement. METHOD AND MATERIALS: The study was a randomized, parallel-group controlled investigation. All patients were treated to increase the KM width before placement of implant-supported prostheses. The implants were placed 3 to 6 months before the interventions. Three techniques were tested: an apically positioned flap (control group), FGG (test group 1), and use of a collagen matrix (test group 2). Biopsy was performed during healing abutment placement by means of a mucotome. RESULTS: A total of 63 patients were recruited and treated, and 58 were available for follow-up visits. After 4 weeks, the KM width gain was 1.93 ± 0.85 mm, 4.85 ± 1.11 mm, and 3.03 ± 0.58 mm, respectively, for control group, test group 1, and test group 2. Postoperative pain was significantly higher in the FGG group than in the others. Edema and hyperemia decreased gradually during the first week without significant differences among groups. CONCLUSION: Despite the limitations of the study, it was found that FGG was the most effective technique to augment the amount of KM in sites of implant placement. The use of a collagen matrix could be a viable alternative to diminish the intervention's impact on patients' postoperative quality of life.