The Accuracy of Zygomatic Implant Placement Assisted by Dynamic Computer-Aided Surgery: A Systematic Review and Meta-Analysis.

PURPOSE: The present systematic review aimed to investigate the accuracy of zygomatic implant (ZI) placement using dynamic computer-aided surgery (d-CAIS), static computer-aided surgery (s-CAIS), and a free-hand approach in patients with severe atrophic edentulous maxilla and/or deficient maxilla. METHODS: Electronic and manual literature searches until May 2023 were performed in the PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases. Clinical trials and cadaver studies were selected. The primary outcome was planned/placed deviation. Secondary outcomes were to evaluate the survival of ZI and surgical complications. Random-effects meta-analyses were conducted and meta-regression was utilized to compare fiducial registration amounts for d-CAIS and the different designs of s-CAIS. RESULTS: A total of 14 studies with 511 ZIs were included (Nobel Biocare: 274, Southern Implant: 42, SIN Implant: 16, non-mentioned: 179). The pooled mean ZI deviations from the d-CAIS group were 1.81 mm (95% CI: 1.34-2.29) at the entry point and 2.95 mm (95% CI: 1.66-4.24) at the apex point, and angular deviations were 3.49 degrees (95% CI: 2.04-4.93). The pooled mean ZI deviations from the s-CAIS group were 1.19 mm (95% CI: 0.83-1.54) at the entry point and 1.80 mm (95% CI: 1.10-2.50) at the apex point, and angular deviations were 2.15 degrees (95% CI: 1.43-2.88). The pooled mean ZI deviations from the free-hand group were 2.04 mm (95% CI: 1.69-2.39) at the entry point and 3.23 mm (95% CI: 2.34-4.12) at the apex point, and angular deviations were 4.92 degrees (95% CI: 3.86-5.98). There was strong evidence of differences in the average entry, apex, and angular deviation between the navigation, surgical guide, and free-hand groups (p < 0.01). A significant inverse correlation was observed between the number of fiducial screws and the planned/placed deviation regarding entry, apex, and angular measurements. CONCLUSION: Using d-CAIS and modified s-CAIS for ZI surgery has shown clinically acceptable outcomes regarding average entry, apex, and angular deviations. The maximal deviation values were predominantly observed in the conventional s-CAIS. Surgeons should be mindful of potential deviations and complications regardless of the decision making in different guide approaches.

Primary Stability of Trabecular Metal Implant in Comparison to Fully Threaded Implants: In Vitro Study Simulating Immediate Implant Placement.

The aim of this study was to evaluate primary stability of 3.7-mm diameter porous tantalum Trabecular Metal (TM) implant, and compare it to fully threaded implants, in the in vitro model of immediate implant placement in the anterior maxilla. A total of 60 implants were placed into bovine ribs using surgical guides. Implants were divided in 3 groups of 20 according to the design: TM, Tapered Screw-Vent (TSV), and NobelReplace. To simulate immediate placement in anterior maxilla, implants were placed under a sharp angle toward the ribs, not fully submerged. Placement angle of 20.7° was calculated after analysis of 148 virtually planned implants on cone beam computerized tomography scans of 40 patients. No statistically significant difference in implant stability quotient (ISQ) was found between TM (65.8 ± 2.6), TSV (64.7 ± 2.7), and NobelReplace (64.6 ± 2.7). TSV implants achieved higher insertion torque (37.0 ± 4.8 Ncm) than TM (32.9 ± 5.2 Ncm) and NobelReplace (23.2 ± 3.3 Ncm). TSV had the shortest insertion time of 13.5 ± 1.0 seconds, compared to 15.2 ± 1.2 seconds for TM, and 19.7 ± 1.7 seconds for NobelReplace. Pearson correlation analysis showed significantly correlated insertion torque and ISQ values for TM group (P = .011, r = .56), a nonsignificant correlation was found for TSV and NobelReplace. The results of the present study indicate that TM implant can achieve good primary implant stability in insertion torque and resonance frequency analysis.

Nanodesigned coatings obtained by plasma electrolytic oxidation of titanium implant and their cytotoxicity.

The titanium implant was treated with plasma electrolytic oxidation and subsequent ionic exchange and thermal treatment in order to obtain bioactive layer consisting of titanium oxide, calcium and sodium titanates and hydroxyapatite, as confirmed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) revealed that the given method, besides corresponding phase composition, enables suitable nanotopology for cell attachment and proliferation. Cytotoxicity investigations by MTT, LDH and propidium iodide assays and light microscopy showed that these coatings were not toxic to L929 cells.

Dynamic Navigation Guidance for Bone Reduction in Maxilla: Case Report.

This case report demonstrates the use of dynamic navigation guidance for bone reduction. Information about smile line position incorporated in a virtual plan and accurate transfer to the surgical field enhances the predictability of the treatment. A virtual wax-up was made, and implant positions along with bone reduction were planned accordingly. Residual teeth in the maxilla were extracted, and bone reduction and zygomatic implant placement were assisted by surgical navigation, while conventional implants were placed using the surgical template, followed by immediate loading. When surgical navigation is used for implant placement, navigated bone reduction can easily be incorporated in the workflow. The accuracy of bone reduction was evaluated together with the accuracy of two zygomatic implants assisted by a navigation system and four conventional implants assisted by a static template. The mean deviation between planned and performed bone reduction was 1.3 ± 0.39 mm (range: 0.8 to 1.7 mm). The accuracy of this procedure corresponds to the accuracy of guided implant placement and can be considered reliable after confirmation through clinical trials.

The effect of anatomy on osteogenesis after maxillary sinus floor augmentation: a radiographic and histological analysis.

OBJECTIVES: To assess how anatomy and osteogenesis correlated with results of maxillary sinus floor augmentation (MSFA). MATERIALS AND METHODS: Patients with partial edentulism and advanced atrophy of the posterior maxillae (≤ 4 mm residual bone height, RBH) underwent MSFA with sole deproteinized bovine bone matrix (DBBM) through a lateral approach. After a 6 to 9-month healing period, bone core biopsies were obtained from the sites of implant insertion for histological evaluation. The correlations between anatomical and histomorphometric variables were analyzed in a multiple regression model. RESULTS: Forty-nine patients were recruited. One biopsy per patient was obtained from the augmented sinus. Thirty-seven bone core biopsies were intact and met the requirement for histomorphometry analysis. The mean (± standard deviation) percentages of vital bone (VB), remaining DBBM, and non-mineralized tissue were 18.25 ± 4.76%, 27.74 ± 6.68%, and 54.08 ± 6.07%, respectively. No statistically significant correlations were found between RBH and VB% (p = 0.44) or between sinus contour and VB% (p = 0.33). However, there was an inverse correlation between the sinus width (SW) and VB % (SW1: R2 = 0.13, p = 0.03; SW2: R2 = 0.15, p = 0.02). CONCLUSIONS: After a healing period of 6-9 months, wider sinuses augmented with DBBM alone tended to have a lower proportion of new bone formation, while RBH and sinus contour did not appear to affect osteogenesis after MSFA. CLINICAL RELEVANCE: This study emphasized the effect of anatomy on osteogenesis after MSFA. The result of the study may have an indication to the clinician that SW is a consideration when selecting the bone grafting material and deciding the healing period of MSFA.

Hedgehog signaling pathway and vitamin D receptor gene variants as potential risk factors in odontogenic cystic lesions.

OBJECTIVES: Genetic variants in the hedgehog signaling pathway and VDR gene are involved in inflammatory responses and neoplastic transformation. Current study investigated whether single-nucleotide polymorphisms in the hedgehog pathway genes PTCH1, GLI1, SMO, and VDR contribute to susceptibility to odontogenic cystic lesions, odontogenic keratocysts, or inflammatory radicular cysts. MATERIAL AND METHODS: Current study examined polymorphisms of PTCH1 (rs357564) and PTCH1 insertion (IVS1-83), GLI1 (rs2228224, rs2228226), SMO (rs2228617), and VDR (rs2228570, rs731236, rs7975232). A case-control study was conducted on 41 keratocyst cases, 43 radicular cyst cases, and control group of 93 healthy individuals without cystic lesions, radiographically confirmed. Single-nucleotide polymorphisms were assessed by real-time and TaqMan SNP genotyping assays, while PTCH1 insertion 18 bp IVS1-83 polymorphism was determined by PCR. RESULTS: The difference in genotype distribution between keratocyst cases and control group was observed for PTCH1 IVS1-83 and GLI1 rs2228224 polymorphism (p = 0.022, p = 0.030, respectively). Homozygous mutant GG genotype within GLI1 rs2228224 is associated with increased susceptibility for odontogenous keratocysts, with adjusted odds ratio of 4.098 (confidence interval of 1.482-11.328, p = 0.007). CONCLUSION: GLI1 rs2228224 and PTCH1 polymorphisms could predispose to odontogenic keratocysts. CLINICAL RELEVANCE: Variants in hedgehog signaling pathway genes, such as GLI1 and PTCH1, and vitamin D receptor gene, might be considered as molecular risk factors in odontogenic cystic lesions and potential targets for novel therapeutic approaches.

Biocompatibility Investigation of New Endodontic Materials Based on Nanosynthesized Calcium Silicates Combined with Different Radiopacifiers.

INTRODUCTION: The aim of this article was to analyze biocompatibility and bioactivity of new endodontic materials on the basis of nanosynthesized calcium silicates (ALBO-MPCA1 and ALBO-MPCA2) combined with different radiopacifiers in comparison with MTA+. METHODS: Morphology of the samples was studied by scanning electron microscopy, and the pH and ion release analysis were also assessed. Biocompatibility of materials' eluates (24-hour, 7-day, and 21-day) was conducted by using MTT test. Twelve New Zealand white rabbits were used for intraosseous implantation. Four calvarial defects per animal were created and filled with freshly prepared investigated materials. RESULTS: Samples mostly consisted of agglomerates built up from nanoparticles, preferably spherical and rod-like. There was no significant difference among pH values of materials' eluates after 24 hours (P > .05). The amount of calcium and aluminum ion release decreased, whereas the amount of magnesium and bismuth (ALBO-MPCA1, MTA+) and barium (ALBO-MPCA2) increased during 21-day period. The metabolic activity of cells increased after the extraction time, except in case of undiluted elutes of ALBO-MPCA2 and ALBO-MPCA1 (21-day). Histologic analysis of the samples revealed newly formed bone tissue with moderate inflammation for all investigated materials, which subsided during 90-day period to mild. Both MTA+ and ALBO-MPCA1 were in direct contact with the newly formed bone tissue. After 90 days, statistically significant difference in hard tissue formation was observed in comparison of MTA+ and ALBO-MPCA1 with control group (P < .05). CONCLUSIONS: Experimental materials ALBO-MPCA1 and ALBO-MPCA2 possess both biocompatibility and bioactivity. Because ALBO-MPCA1 provokes favorable biological response, it is especially good candidate for further clinical investigations.

Association of vdr, cyp27b1, cyp24a1 and mthfr gene polymorphisms with oral lichen planus risk.

OBJECTIVES: The current study investigated the association between VDR EcoRV (rs4516035), FokI (rs2228570), ApaI (rs7975232) and TaqI (rs731236), CYP27B1 (rs4646536), CYP24A1 (rs2296241), and MTHFR (rs1801133) gene polymorphisms and risk of oral lichen planus (OLP) occurrence. MATERIALS AND METHODS: The study group consisted of 65 oral lichen planus patients and 100 healthy blood donors in the control group. Single nucleotide polymorphisms were genotyped by real time PCR or PCR-restriction fragment length polymorphism (RFLP) method. RESULTS: Heterozygous as well as mutated genotype of vitamin D receptor (VDR) FokI (rs2228570) polymorphism was associated with increased oral lichen planus risk in comparison with wild type genotype (odds ratio (OR) = 3.877, p = 0.017, OR = 38.153, p = 0.001, respectively). A significantly decreased OLP risk was observed for heterozygous genotype of rs2296241 polymorphism in CYP24A1 gene compared with the wild type form (OR = 0.314, p = 0.012). VDR gene polymorphisms ApaI and TaqI were in linkage disequilibrium (D' = 0.71, r(2) = 0.22). Identified haplotype AT was associated with decreased OLP risk (OR = 0.592, p = 0.047). CONCLUSION: Our results highlight the possible important role of VDR FokI (rs2228570) and CYP24A1 rs2296241 gene polymorphisms for oral lichen planus susceptibility. CLINICAL RELEVANCE: Identification of new molecular biomarkers could potentially contribute to determination of individuals with OLP predisposition.

Efficiency of photodynamic therapy in the treatment of peri-implantitis ­ A three-month randomized controlled clinical trial.

Introduction: Peri-implantitis is an inflammatory lesion of peri-implant tissues. Eradication of the causative bacteria and decontamination of the implant surface is essential in achieving predictable and stabile clinical results. Photodynamic therapy (PDT) is non-invasive adjuvant therapeutic method to surgery in the treatment of bacterial infection. Objective: The aim of this study was to evaluate early clinical and microbiological outcomes of periimplantitis after surgical therapy with adjuvant PDT. Methods: Fifty-two diagnosed peri-implantitis sites were divided into two groups. PDT was used for decontamination of implant surface in the study group; in the control group, chlorhexidine gel (CHX) followed by saline irrigation was applied. Several clinical parameters were recorded before the treatment (baseline values) and three months after surgical treatment. Samples for microbiological identification were collected before therapy, during the surgical therapy (before and after decontamination of implant surface), and three months thereafter, and analyzed with identification systems using biochemical analysis. Results: The use of PDT resulted in significant decrease of bleeding on probing in comparison to CHX (p < 0.001). It showed significant decontamination of implant surfaces with complete elimination of anaerobic bacteria immediately after surgical procedure and three months later. Conclusion: The results indicate that PDT can be used as an adjuvant therapy to surgery for decontamination of implant surface and surrounding peri-implant tissues within the treatment of peri-implantitis.

TLR2, TLR3, TLR4 and CD14 gene polymorphisms associated with oral lichen planus risk.

The aim of this study was to assess whether polymorphisms in toll-like receptor (TLR) and cluster of differentiation 14 (CD14) genes are associated with oral lichen planus (OLP) risk and clinical course of the disease. The study group consisted of 101 patients with confirmed OLP and 104 healthy blood donors without systemic or oral mucosal diseases. Single nucleotide polymorphisms of TLR2 (rs3804099), TLR3 (rs3775291 and rs5743312), TLR4 (rs4986790 and rs4986791), and CD14 (rs2569190) genes were genotyped using real-time PCR or PCR-restriction fragment length polymorphism (PCR-RFLP). The rs5743312 TLR3 gene polymorphism was associated with increased OLP risk in comparison with the wild type genotype (OR = 15.984, P = 0.011). No association with OLP risk was observed for the polymorphisms studied in TLR2, TLR4 and CD14 genes or for the rs3775291 polymorphism of the TLR3 gene. The polymorphisms of the TLR3 gene were in linkage disequilibrium (D' = 1, r(2) = 0.1). Identified haplotypes were not associated with the risk of OLP. The findings of the current study suggest that the TT genotype of the rs5743312 TLR3 gene polymorphism may play a significant role in the aetiology of OLP.