Less marginal bone loss around bone-level implants restored with long abutments: A systematic review and meta-analysis.

The aim of this study was to investigate the biological outcomes of bone-level implants restored with long vs. short abutments, with regard to the 'one abutment at one time' protocol. The systematic search was performed in five databases: MEDLINE (PubMed), EMBASE, Web of Science, Scopus, and CENTRAL for randomized controlled trials up to January 14, 2023. Data were collected for marginal bone loss, bleeding on probing, and probing pocket depth by two reviewers. As effect size measure, mean difference (MD), and risk ratio (RR) were used for continuous and categorical outcomes, R-statistics software was used for conducting statistical analyses. For quality and certainty assessment, Risk of Bias Tool 2, ROBINS-I, and GRADE approach were used. The search resulted in 4055 records without any duplicates. After title, abstract, and full-text analysis, eight articles were found eligible for inclusion. Bone-level and platform-switched implants presented less marginal bone loss after 6 months and 1 year as well, when long abutments were used (MD 0.63, 95% CI: [-0.16; 1.42]) and (MD 0.26, 95% CI: [-0.02; 0.53]). However, subgroup analysis revealed no difference in marginal bone loss when applying 'one abutment at one time' protocol (p = 0.973). Bleeding on probing and probing pocket depth presented similarly good results in both groups without almost any differences (RR 0.97, 95% CI: [0.76; 1.23]) and (MD -0.05, 95% CI: [-1.11; 1.01]). Longer abutments on bone-level implants seem to be a favorable choice for decreasing early marginal bone loss, irrespective of connection timing.

Monolithic zirconia as a valid alternative to metal-ceramic for implant-supported single crowns in the posterior region: A systematic review and meta-analysis of randomized controlled trials.

STATEMENT OF PROBLEM: Technical complication rates of standard metal-ceramic implant-supported posterior restorations are relatively high. Whether monolithic zirconia crowns represent a more successful alternative is unclear. PURPOSE: The purpose of this systematic review and meta-analysis was to compare the clinical outcomes of posterior monolithic zirconia and metal-ceramic implant-supported single crowns. MATERIAL AND METHODS: A search was conducted in MEDLINE, Scopus, Embase, Web of Science, and CENTRAL databases for randomized controlled trials up to April 2023 with a follow-up time of at least 1 year. Restoration and implant survival and failure rates, marginal bone loss (MBL), bleeding on probing (BOP), and technical complications were analyzed by 2 reviewers. Statistical analyses were conducted using the R-statistics software program. The risk of bias was assessed by the Cochrane Risk of Bias Tool 2 (RoB 2), and the certainty of evidence by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. RESULTS: A total of 11 out of 2030 records were identified by title and abstract, and 4 records were included after full-text analysis. The statistical analysis revealed no significant difference in MBL (MD -0.11, 95% CI: [-0.25; 0.03]), BOP (OR 0.66, 95% CI: [0.25; 1.77]), or implant failure (OR 1.30, 95% CI: [0.24; 7.08]). Monolithic zirconia presented significantly less chipping over 1 year (OR 0.17, 95% CI: [0.03; 0.99]). The chipping rate was 0% for monolithic zirconia and 7.61% for metal-ceramic. Based on a narrative review, the restoration survival rate was 97.5% in the monolithic zirconia group and 99.1% in the metal-ceramic group. CONCLUSIONS: Monolithic zirconia showed favorable short-term survival rates and had significantly less chipping over 1 year. Regarding MBL, BOP, and failure rates, both restoration types presented similar results at the 1-year follow-up.

Three-dimensional volumetric assessment of hard tissue alterations following horizontal guided bone regeneration using a split-thickness flap design: A case series.

OBJECTIVES: To analyze morphological, volumetric, and linear hard tissue changes following horizontal ridge augmentation using a three-dimensional radiographic method. METHODS: As part of a larger ongoing prospective study, 10 lower lateral surgical sites were selected for evaluation. Horizontal ridge deficiencies were treated with guided bone regeneration (GBR) using a split-thickness flap design and a resorbable collagen barrier membrane. Following the segmentation of baseline and 6-month follow-up cone-beam computed tomography scans, volumetric, linear, and morphological hard tissue changes and the efficacy of the augmentation were assessed (expressed by the volume-to-surface ratio). RESULTS: Volumetric hard tissue gain averaged 605.32 ± 380.68 mm3. An average of 238.48 ± 127.82 mm3 hard tissue loss was also detected at the lingual aspect of the surgical area. Horizontal hard tissue gain averaged 3.00 ± 1.45 mm. Midcrestal vertical hard tissue loss averaged 1.18 ± 0.81 mm. The volume-to-surface ratio averaged 1.19 ± 0.52 mm3/mm2. The three-dimensional analysis showed slight lingual or crestal hard tissue resorption in all cases. In certain instances, the greatest extent of hard tissue gain was observed 2-3 mm apical to the initial level of the marginal crest. CONCLUSIONS: With the applied method, previously unreported aspects of hard tissue changes following horizontal GBR could be examined. Midcrestal bone resorption was demonstrated, most likely caused by increased osteoclast activity following the elevation of the periosteum. The volume-to-surface ratio expressed the efficacy of the procedure independent of the size of the surgical area.

The use of autogenous tooth bone graft is an efficient method of alveolar ridge preservation - meta-analysis and systematic review.

BACKGROUND: Ridge resorption following tooth extraction may be reduced by alveolar ridge preservation (ARP). Previous randomized clinical trials and systematic reviews have suggested that autogenous tooth bone graft (ATB) can be an effective alternative material for ARP. However, the results are heterogeneous. Therefore, our research aimed to evaluate the efficacy of ATB in ARP. METHODS: A systematic search was conducted in Cochrane Library, Embase, MEDLINE and Scopus for studies published from inception to 31 November 2021. We searched searched for randomized, non-randomized controlled trials and case series reporting on ATB use for ARP. The primary outcome was the ridge width difference pre- and post-surgery, measured in millimetres (mm) measured on CBCT (cone beam computed tomography). The secondary outcomes were the histological results. We followed the PRISMA2020 recommendations for reporting our systematic review and meta-analysis. RESULTS: The analysis included eight studies for the primary and six for the secondary outcomes. The meta-analysis revealed a positive ridge preservation effect with a pooled mean difference ridge width change of -0.72 mm. The pooled mean residual graft proportion was 11.61%, and the newly formed bone proportion was 40.23%. The pooled mean of newly formed bone proportion was higher in the group where ATB originated from both the root and crown of the tooth. CONCLUSIONS: ATB is an effective particulate graft material in ARP. Complete demineralization of the ATB tends to decrease the proportion of newly formed bone. ATB can be an attractive option for ARP. TRIAL REGISTRATION: The study protocol was registered on PROSPERO (CRD42021287890).

Efficacy of a new-generation platelet-rich fibrin in the treatment of periodontal intrabony defects: a randomized clinical trial.

BACKGROUND: The aim of the study was to clinically evaluate the healing of intrabony defects after treatment with a new generation of platelet-rich fibrin (A-PRF+) respect to enamel matrix derivative (EMD). METHODS: Thirty (30) intrabony defects of 18 patients (9 males, 9 females) were randomly treated with A-PRF+ (test, n = 15) or EMD (control, n = 15). The following clinical parameters were recorded at baseline and 6 months after surgery: pocket depth (PD), gingival recession (GR) and clinical attachment level (CAL). After debridement the intrabony defects were filled with A-PRF+ in the test group, respectively with EMD in the control group, and fixed with sutures to ensure wound closure and stability. RESULTS: Both treatment methods resulted in statistically significant PD reductions, respectively CAL gains six months post-operatively. No statistically significant differences were found between the two groups as the mean CAL gain was 2.33 ± 1.58 mm in the A-PRF+ group, respectively 2.60 ± 1.18 mm in the EMD group (p < 0.001). CONCLUSION: Within the limits of this study the new-generation platelet-rich fibrin seems to be as clinically effective as EMD during surgical treatment of intrabony defects. Treatment with A-PRF+ or EMD resulted in reliable clinical outcomes. The use of A-PRF+ as a human autologous product can give a positive impact on periodontal healing. Clinical Relevance A-PRF+ may be suitable for the treatment of intrabony periodontal defects. Trial registration number (TRN) NCT04404374 (ClinicalTrials.gov ID).

Alveolar cleft reconstruction utilizing a particulate autogenous tooth graft and a novel split-thickness papilla curtain flap - A retrospective study.

During secondary alveolar cleft grafting, the use of autogenous cancellous bone harvested from the iliac crest is still considered the gold standard. Due to the risk of donor-site morbidity and excessive graft resorption, alternative grafting materials (e.g. intraoral bone, xenografts) have been tested. Autogenous tooth bone graft (ATB) is a novel material derived from extracted teeth. ATB has successfully been used in pre-prosthetic and periodontal surgery for hard-tissue reconstruction. Seven patients with unilateral cleft lip and palate were treated with ATB, using their own deciduous teeth for grafting. Defects were accessed utilizing a novel split-thickness papilla curtain flap. Cone-beam computed tomography scans were taken prior to and 3 months following cleft surgery to assess graft integration, graft stability, and the volume of the newly formed hard tissues. Hard-tissue gain, as measured at the 3-month follow-up, averaged 0.65 cm3 ± 0.26 cm3. Results showed acceptable graft integration and stability at the 3-month follow-up, with no adverse effects or excessive resorption of the graft. The use of ATB might be a feasible alternative for alveolar cleft grafting. However, long-term studies using a large sample size are required to derive further conclusions.

Evaluation of the accuracy of intraoral scanners for complete-arch scanning: A systematic review and network meta-analysis.

OBJECTIVES: This network meta-analysis (NMA) aimed to compare the complete-arch scanning accuracy of different intraoral scanners (IOSs) to that of reference standard tessellation language (STL) files. DATA: Studies comparing the trueness and precision of IOS STL files with those of reference STL scans for different arch types (dentate, edentulous, completely edentulous with implants, and partially edentulous with implants) were included in this study. SOURCES: An electronic search of five databases restricted to the English Language was conducted in October 2021. STUDY SELECTION: A total of 3,815 studies were identified, of which 114 were eligible for inclusion. After study selection and data extraction, pair-wise comparison and NMA were performed to define the accuracy of scanning for four arch subgroups using four outcomes (trueness and precision expressed as mean absolute deviation and root mean square values). Cochrane guidelines and the QUADAS-2 tool were used to assess the risk of bias. GRADE was used for certainty assessment. RESULTS: Fifty-three articles were included in this NMA. Altogether, 26 IOSs were compared directly and indirectly in 10 network systems. The accuracy of IOSs scans were not significantly different from the reference scans for dentate arches (three IOSs), edentulous arches (three IOSs), and completely edentulous arches with implants (one IOS). The accuracy of the IOSs was significantly different from the reference scans for partially edentulous arches with implants. Significant accuracy differences were found between the IOSs, regardless of clinical scenarios. CONCLUSIONS: The accuracy of complete-arch scanning by IOSs differs based on clinical scenarios. CLINICAL SIGNIFICANCE: Different IOSs should be used according to the complete arch type.

Digital Hybrid Model Preparation for Virtual Planning of Reconstructive Dentoalveolar Surgical Procedures.

Virtual, hybrid three-dimensional (3D) model acquisition is presented in this article, utilizing the sequence of radiographic image segmentation, spatial registration, and free-form surface modeling. Firstly cone-beam computed tomography datasets were reconstructed with a semi-automatic segmentation method. Alveolar bone and teeth are separated into different segments, allowing 3D morphology, and localization of periodontal intrabony defects to be assessed. The severity, extent, and morphology of acute and chronic alveolar ridge defects are validated concerning adjacent teeth. On virtual complex tissue models, positions of dental implants can be planned in 3D. Utilizing spatial registration of IOS and CBCT data and subsequent free-form surface modeling, realistic 3D hybrid models can be acquired, visualizing alveolar bone, teeth, and soft tissues. With the superimposition of IOS and CBCT soft tissue, thickness above the edentulous ridge can be assessed about the underlying bone dimensions; therefore, flap design and surgical flap management can be determined, and occasional complications may be avoided.