Effects of Simvastatin-Loaded Nanomicelles on the Early Preservation of Tooth Extraction Sites.

Object: The present study intended to evaluate the effect of simvastatin-loaded nanomicelles (SVNs) on promoting new bone formation and reducing alveolar ridge resorption at the tooth extraction sites at the early healing of the extraction sockets. Methods: SVNs were synthesized using a dialysis method. The rabbit tooth extraction model was established, SVNs and simvastatin (SV) were loaded on gelatin sponge and inserted into the extraction socket. CBCT scans were performed at 0, 2, and 4 weeks postoperatively to evaluate bone formation and alveolar ridge absorption in the extraction sockets. And all the animals were sacrificed and the mandibles were harvested. And HE staining and Masson staining were used for histological evaluation of the bone formation in the extraction sockets. Results: Radiographic evaluation showed that compared with the blank control group, at 2 and 4 weeks after extraction, SVNs increased the new bone density in the extraction sockets by 75.7% and 96.5%, and reduced the absorption rate of alveolar ridge length at the extraction sites by 60.8% and 49.1%, respectively. Histological evaluation showed that SVNs significantly improved the maturation of new bone tissue in the extraction sockets. Conclusion: SVNs can significantly accelerate healing and effectively reduce the absorption of alveolar ridge at the extraction sites in the early stage of tooth extraction socket healing.

Alveolar regeneration of the post-extraction site with cortical deficiency using the Lamina Socket Sealing technique: Retrospective study with histomorphometric analysis of regenerated bone and evaluation of soft tissue changes. Part 2/2.

PURPOSE: This retrospective observational study evaluated the histomorphometric and soft tissue outcome of a new alveolar ridge preservation (ARP) technique, "Lamina Socket Sealing" (LSS) technique, using a porcine barrier. METHODS: Patients with maxillary premolars to be extracted and extensive alveolar wall defects were enrolled and treated. Porcine-derived barriers and mesenchymal membrane were used to seal the extraction socket with alveolar particulate graft. An optical scan of the dental arches was performed with an intraoral scanner (Trios 3, 3Shape) at baseline and at a 4-month follow-up. At the time of implant placement, a bone sample was taken at the implant site with a trephine drill (Hager & Meisinger) and subjected to histomorphometric analysis. RESULTS: 36 subjects (21 females and 15 males) were treated. At 4 months, histomorphometric analysis of the bone samples revealed that the percentage of vital bone was 42.87%, 8.75% of residual granules, 30.76% of soft tissue. Linear comparison of the width of the keratinized gingiva showed an increase (mean + SE) of 3.16 ± 0.35 mm. The net volumetric change of soft tissue was (mean + SE) +28.41 ± 19.52 mm³. CLINICAL SIGNIFICANCE: This alveolar ridge preservation technique (Lamina Socket Sealing) using a resorbable heterologous cortical lamina with a flapless approach has proven effective in maintaining adequate soft tissue and grafting of particulate bone and lamina, with a high percentage of viable bone.

Alveolar regeneration of the post-extraction site with cortical deficiency using the Lamina Socket Sealing technique: A retrospective study with clinical, radiographic and histomorphometric analysis. Part 1/2.

PURPOSE: This retrospective observational study aims to evaluate the outcome of a new alveolar ridge preservation (ARP) technique, "Lamina Socket Sealing" (LSS) technique, using a porcine barrier. METHODS: 36 subjects with maxillary premolars to be extracted and extensive alveolar wall defects were enrolled and treated. Porcine-derived barriers and mesenchymal membrane were used to seal the extraction socket with alveolar particulate graft. The outcome variables were: radiographical bone changes and clinical outcomes. RESULTS: 36 subjects, 21 females and 15 males were treated. The change in mm (mean + SE) of horizontal ridge width from baseline to 4 months after surgery at the coronal level of the alveolus was +1.25 ± 0.20 mm (P< 0.05), mean level was +0.34 ± 0.1 mm (P< 0.05) and at the apical level was +0.08 ± 0.17 mm (P> 0.05) which was not statistically significant. The buccal and palatal height changes in mm (mean + SE) from baseline to 4 months after surgery were respectively 1.21 ± 0.17 mm for the buccal wall (P< 0.05) and 1.06 ± 0.24 mm for the palatal wall (P< 0.05). The bone volume of all sites allowed for the placement of the planned implants. CLINICAL SIGNIFICANCE: The alveolar ridge preservation technique (Lamina Socket Sealing) using resorbable heterologous cortical lamina with flapless approach allowed not only the preservation of the damaged post-extraction socket, but also minimal ridge augmentation, according to the principles of guided bone regeneration.

Comparison of Direct Intraoral Scan and Traditional Impression for CAD/CAM Mandibular Overdenture Base: RCT on Peri-implant Marginal Bone Changes.

AIM: This study aimed to evaluate the impact of digital vs traditional impression techniques on peri-implant vertical bone resorption in the creation of mandibular overdenture bases supported by four implants using CAD/CAM technology. MATERIALS AND METHODS: Twenty edentulous patients were placed in four mandibular implants and randomly divided into groups: (A) the control group (CIG) (n = 10); patients obtained CAD/CAM denture base using conventional impression technique and group (B) the study (DIG) group (n = 10); patients obtained CAD/CAM denture base using digital impression technique. Peri-implant vertical bone height was measured immediately (T0), 6 (T6), and 12 (T12) months after insertion. Peri-implant vertical bone loss (VBL) was calculated first 6 months (T1), the second 6 months (T2), and 1 year (T3) after insertion. RESULTS: For both groups, the survival rates of inserted implants were 100%. The amount of VBL in the first year in both groups was within normal ranges. In both groups, VBL significantly decreased over time. The control group recorded significantly higher VBL than (DIG) group at T2 (p = 0.006) and at T3 (p = 0.005). CONCLUSION: Digital intraoral scanning technique may be considered a more beneficial registration method than traditional impression technique for the construction of CAD/CAM 4-implant-assisted overdenture base regarding the preservation of vertical bone levels. CLINICAL SIGNIFICANCE: Both digital intraoral scanners and conventional impression techniques can be used for the construction of CAD/CAM-implant-assisted overdenture bases regarding the preservation of peri-implant vertical bone resorption. How to cite this article: Seifeldeen AR, Aboelez MA, Gebreel AA, et al. Comparison of Direct Intraoral Scan and Traditional Impression for CAD/CAM Mandibular Overdenture Base: RCT on Peri-implant Marginal Bone Changes. J Contemp Dent Pract 2024;25(6):527-534.

Minocycline reduces alveolar bone loss and bone damage in Wistar rats with experimental periodontitis.

This study aimed to investigate the impact of minocycline on the alveolar bone in experimental periodontitis in rats. Thirty Wistar rats were randomly assigned to three groups: control without periodontitis; experimental periodontitis induced by ligature; experimental periodontitis + intraperitoneal administration minocycline for seven days. Ligatures remained in place in both periodontitis groups for 14 days. At the end of the experiment, the animals were euthanized and one hemimandible underwent micro-computed tomography (micro-CT) analysis to assess vertical bone loss and alveolar bone quality. Histopathological analysis was performed on the other hemimandible. Statistical analysis was performed using ANOVA with Tukey's post-test (p<0.05). The results showed a significant reduction in vertical bone loss in the animals treated with minocycline compared with untreated animals. Minocycline also preserved the alveolar bone thickness, number, spacing, and bone volume to tissue volume ratio. Histopathological analysis indicated that minocycline reduced bone resorption, decreased inflammatory response, and maintained the bone collagen fibers. This study demonstrated the effectiveness of minocycline in reducing vertical bone loss and preserved bone quality in rats with experimental periodontitis. The results of this study indicate that minocycline has the potential to serve as an additional treatment option for periodontitis. However, further research is warranted to assess the efficacy and safety of minocycline use in patients with periodontitis.

Marginal bone loss and soft tissue health around two-implant mandibular overdenture retained with milled versus selective laser melted cobalt chromium bar: a randomized clinical trial.

BACKGROUND: To assess marginal bone loss and soft tissue health around two-implant mandibular overdenture retained with milled versus selective laser-melted cobalt chromium (Co-Cr) bars. METHOD: This research was set to be a parallel, triple-blinded, randomised controlled trial. Twenty completely edentulous patients received new conventional complete dentures according to conventional techniques. Two implants were placed at mandibular canine areas bilaterally, and patients were randomly allocated into two equal groups: the milled Co-Cr bar group and the selective laser melted (SLM) Co-Cr bar group. Marginal bone loss (MBL), modified plaque index (mPI), modified gingival index (mGI), and probing depth (PD) were evaluated at 0-month (baseline), 6-month, and 12-month follow-up visits. Repeated measures ANOVA test and Bonferroni's post-hoc test were used for parametric data as PD, while for non-parametric data as MBL, mGI, and mPI, Mann-Whitney U test and Friedman's test were used. A P-value ≤ 0.05 was set as the statistical level of significance. The study protocol was approved by the Faculty Research Ethics Committee at Minia University (636 4/10/2022). Registration for the clinical trial was made retrospectively on clinicaltrials.gov with ID NCT06401200 at 04/30/2024. RESULTS: The follow-up period (one year) was completed without a dropout. Regarding MBL, no statistically significant difference was found between the two groups throughout the study. However, the milled group showed significantly increased MBL from 0- to 6-month follow up period. In both groups, mPI increased significantly from 0- to 6-months post-loading. On the other hand, no statistically significant difference between the two groups was found regarding mPI and mGI throughout the study follow-up periods. The PD was significantly lower in the milled compared to the SLM group at the 6- and 12-month follow up period. CONCLUSION: Two-implant mandibular overdenture retained with milled or SLM Co-Cr bar can provide an acceptable treatment option for completely edentulous patients regarding marginal bone loss and soft tissue outcomes.

Periodontal regenerative therapy using recombinant human fibroblast growth factor (rhFGF)-2 in combination with carbonate apatite granules or rhFGF-2 alone: 12-month randomized controlled trial.

OBJECTIVES: This randomized controlled trial compared the outcomes of recombinant human fibroblast growth factor (rhFGF)-2 plus carbonate apatite (CO3Ap) granules with rhFGF-2 alone in the treatment of intrabony periodontal defects. MATERIALS AND METHODS: Patients with Stage III Grade B/C periodontitis who had completed initial periodontal therapy and had intrabony defects with a depth of ≥ 3 mm were included. Defects were treated solely with rhFGF-2 (control) or rhFGF-2 plus CO3Ap (test). Periodontal parameters and a patient-reported outcome measure (PROM) were assessed at baseline, at 6, 9 and 12 months postoperatively. The primary outcome was the change in clinical attachment level (CAL) from baseline to 12 months postoperatively. Using the Friedman test with Dunn's post-test, intragroup data were compared over time, and Mann-Whitney U test was used to assess intergroup data at each time point. RESULTS: Forty-eight sites in 38 patients were subjected to analysis. At 12 months postoperatively, CAL in both groups showed a significant improvement from baseline (p < 0.001). CAL gain was 3.4 ± 1.3 mm in the test group and 3.2 ± 1.2 mm in the control group, with no significant intergroup difference (p = 0.567). Radiographic bone fill in the test group (67.2%) was significantly greater than in the control group (32.4%) (p < 0.001). PROM scores showed no difference between groups. CONCLUSIONS: At 12 months, the outcomes including CAL gain and PROM showed no significant differences between groups, although the combination treatment enhanced radiographic bone fill. CLINICAL RELEVANCE: The use of rhFGF-2 (with/without CO3Ap) could lead to significant improvement in clinical parameters in the treatment of intrabony periodontal defects. The benefit of adding CO3Ap to rhFGF-2 therapy needs further evaluation. CLINICAL TRIAL REGISTRATION NUMBER: The University Hospital Medical Information Network-Clinical Trials Registry (UMIN-CTR) : UMIN000040783.

Regeneration of combined severe periodontal defects and vertical ridge defects using recombinant human platelet-derived growth factor-BB: A case series.

Dental implants are a reliable treatment option for restoring missing teeth, but adequate bone quantity and quality are crucial for success. This case series presents four cases treated by different clinicians, all following very similar concepts for combined periodontal and vertical ridge augmentation using recombinant human platelet-derived growth factor-BB. All cases involved a severe periodontal defect requiring either extraction of the adjacent tooth or periodontal regeneration. Different bone grafts and membrane types were utilised. Although true periodontal regeneration cannot be said categorically to have occurred due to a lack of histological evidence, the clinical and radiographic findings suggest almost complete bone fill in all cases. This case series demonstrates that combined periodontal and vertical ridge augmentation using recombinant human platelet-derived growth factor-BB could be successful, but proper case selection and patient preparation for the possibility of multiple surgical procedures are recommended. Conflict-of-interest statement: At the time of preparing this manuscript, Dr Saleh was a clinical advisor for Lynch Biologics, Franklin, TN, USA. The other authors declare that they have no conflicts of interest relating to this study.

The efficiency of two different synthetic bone graft materials on alveolar ridge preservation after tooth extraction: a split-mouth study.

BACKGROUND: Alveolar Bone loss occurs frequently during the first six months after tooth extraction. Various studies have proposed different methods to reduce as much as possible the atrophy of the alveolar ridge after tooth extraction. Filling the socket with biomaterials after extraction can reduce the resorption of the alveolar ridge. We compared the height of the alveolar process at the mesial and distal aspects of the extraction site and the resorption rate was calculated after the application of HA/ß-TCP or synthetic co-polymer polyglycolic - polylactic acid PLGA mixed with blood to prevent socket resorption immediately and after tooth extraction. METHODS: The study was conducted on 24 extraction sockets of impacted mandibular third molars bilaterally, vertically, and completely covered, with a thin bony layer. HA/ß-TCP was inserted into 12 of the dental sockets immediately after extraction, and the synthetic polymer PLGA was inserted into 12 of the dental sockets. All sockets were covered completely with a full-thickness envelope flap. Follow-up was performed for one year after extraction, using radiographs and stents for the vertical alveolar ridge measurements. RESULTS: The mean resorption rate in the HA/ß-TCP and PLGA groups was ± 1.23 mm and ± 0.1 mm, respectively. A minimal alveolar bone height reduction of HA/ß-TCP was observed after 9 months, the reduction showed a slight decrease to 0.93 mm, while this rate was 0.04 mm after 9 months in the PLGA group. Moreover, the bone height was maintained after three months, indicating a good HA/ß-TCP graft performance in preserving alveolar bone (1.04 mm) while this rate was (0.04 mm) for PLGA. CONCLUSION: The PLGA graft demonstrated adequate safety and efficacy in dental socket preservation following tooth extraction. However, HA/ß-TCP causes greater resorption at augmented sites than PLGA, which clinicians should consider during treatment planning.

Mandibular overdentures retained by 1 or 2 implants: a 5-year randomized clinical trial on implant stability and peri-implant outcomes.

AIM: This is a report of the 5-year results of a two-group parallel randomized clinical trial comparing longitudinal implant stability, and clinical and radiographic peri-implant outcomes of mandibular overdentures retained by one (1-IOD group) or two (2-IOD group) implants. METHODS: All participants received 4.1 mm diameter tissue-level implants (Straumann® Standard Plus - SLActive®, Institut Straumann AG), installed in the mandible midline (1-IOD; n = 23) or the lateral incisor-canine area bilaterally (2-IOD; n = 24), and loaded after 3 weeks. Implant Stability Quotient (ISQ) was measured using a resonance frequency device (Osstell® Mentor, Integration Diagnostics) at implant placement, after three weeks (loading), and at the 6-month, 1-, 3-, and 5-year follow-ups. Marginal bone loss and clinical implant outcomes (plaque, calculus, suppuration and bleeding) were assessed periodically up to 5 years after loading. RESULTS: Only minor changes in marginal bone level were observed after 5 years (mean = 0.37; SD = 0.44 mm), and satisfactory and stable peri-implant parameters were observed throughout the 5-year follow-up. No significant differences between groups were found. Overall, the mean primary implant stability was considered high (> 70) for the two groups (1-IOD = 78.1 ± 4.5; 2-IOD = 78.0 ± 5.8). No noticeable changes were observed between implant insertion and loading. A marked increase was observed from insertion to the 6-month follow-up - the mean difference for the 1-IOD group was + 5.5 ± 5.5 (Effect size = 1.00), while for the 2-IOD group, the mean difference was + 6.0 ± 5.6 (Effect size = 1.08). No relevant changes were observed throughout the follow-up periods up to 5 years. Linear mixed-effect model regression showed no influence of the bone-related variables (p > 0.05) and the number of implants (p = 0.087), and a significant effect of the time variable (p < 0.001). CONCLUSION: Satisfactory peri-implant outcomes and stable secondary stability suggest good clinical performance and successful long-term osseointegration of the implants for single and two-implant mandibular overdentures. Using a single implant to retain a mandibular overdenture does not seem to result in detrimental implant loading over the five years of overdenture use. CLINICAL RELEVANCE: This study corroborates the use of a single implant to retain a mandibular denture.

PHD2 shRNA-Modified Bone Marrow Mesenchymal Stem Cells Facilitate Periodontal Bone Repair in Response to Inflammatory Condition.

OBJECTIVE: To investigate whether bone marrow mesenchymal stem cells (BMMSCs) modulate periodontal bone repair through the hydroxylase domain-containing protein 2 (PHD2)/hypoxia- inducible factor-1 (HIF-1) signalling pathway in response to inflammatory conditions. METHODS: Osteogenic differentiation of PHD2 shRNA-modified BMMSCs and the possible mechanism were explored in an inflammatory microenvironment stimulated by porphyromonas gingivalis lipopolysaccharide (Pg-LPS) in vitro. The effect of PHD2 gene-modified BMMSCs on periodontal bone loss was evaluated with experimental periodontitis. RESULTS: Pg-LPS stimulation greatly impaired the osteogenic differentiation of BMMSCs, whereas the silence of PHD2 significantly enhanced the osteogenesis of BMMSCs. More importantly, increased level of vascular endothelial growth factor (VEGF) was detected under Pg-LPS stimulation, which was verified to be associated with the augmented osteogenesis. In experimental periodontitis, PHD2-modified BMMSCs transplantation elevated osteogenic parameters and the expression of VEGF in periodontal tissue. CONCLUSION: This study highlighted that PHD2 gene silencing could be a feasible approach to combat inflammatory bone loss by rescuing the dysfunction of seed cells.

Analysis of risk indicators for implant failure in patients with chronic periodontitis.

Dental implant restoration shows an effective method for the rehabilitation of missing teeth. The failure rate of periodontal implants in patients with chronic periodontitis is associated with periodontal flora, inflammation, and long-term periodontal bone resorption caused by chronic periodontitis. However, the therapeutic effects of dental implant restoration on inflammation in patients with chronic periodontitis have not addressed. The purpose of this study is to evaluate the risk indicators for inflammation, bone loss and implant failure in patients with chronic periodontitis. A total of 284 patients with dental implant restoration were recruited and divided into periodontally healthy patients (n = 128) and chronic periodontitis patients (n = 156). Periodontal indices including probing depth (PD), sulcus bleeding index (SBI), plaque index (PLI), gingival bleeding (GIL) and bleeding on probing (BOP) were compared in two groups. Inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1 (IL-1), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) levels at baseline, 6 and 12 months after surgery, and the implant survival rate at 12 months after surgery, as well as the risk factors associated with failure of dental implant were also assessed. Outcomes demonstrated that patients in the chronic periodontitis group had higher values of periodontal indices than those in the periodontally healthy group. All inflammatory parameters in the chronic periodontitis group were higher than those in the periodontally healthy group and negatively associated with the chronic periodontal index (CPI) in chronic periodontitis patients. Chronic periodontitis patients had higher the prevalence of mucositis and peri-implantitis than patients with healthy periodontium. Implant diameter, length and design was associated with the risk of implant failure for chronic periodontitis patients receiving dental implant. The cumulative implant failure rate and incidence of implant fractures for chronic periodontitis patients at 12 months after surgery were 12.10% and 7.23% (p < 0.05), respectively, while were lower in the heathy periodontitis patients. Location, diameter, implant design, immediate loading and bone defect were risk indicators for bone loss for dental implant patients. The risk factors associated with failure of dental implant was higher in chronic periodontitis patients than patients in the periodontally healthy group (14.25% vs. 4.92%, p < 0.05). In conclusion, data in the current study indicate that inflammation is a risk indicator bone loss, implant fracture and implant failure in patients with chronic periodontitis.

GPR40/GPR120 Agonist GW9508 Improves Metabolic Syndrome-Exacerbated Periodontitis in Mice.

G protein-coupled receptor (GPR)40 and GPR120 are receptors for medium- and long-chain free fatty acids. It has been well documented that GPR40 and GPR120 activation improves metabolic syndrome (MetS) and exerts anti-inflammatory effects. Since chronic periodontitis is a common oral inflammatory disease initiated by periodontal pathogens and exacerbated by MetS, we determined if GPR40 and GPR120 activation with agonists improves MetS-associated periodontitis in animal models in this study. We induced MetS and periodontitis by high-fat diet feeding and periodontal injection of lipopolysaccharide, respectively, and treated mice with GW9508, a synthetic GPR40 and GPR120 dual agonist. We determined alveolar bone loss, osteoclast formation, and periodontal inflammation using micro-computed tomography, osteoclast staining, and histology. To understand the underlying mechanisms, we further performed studies to determine the effects of GW9508 on osteoclastogenesis and proinflammatory gene expression in vitro. Results showed that GW9508 improved metabolic parameters, including glucose, lipids, and insulin resistance. Results also showed that GW9508 improves periodontitis by reducing alveolar bone loss, osteoclastogenesis, and periodontal inflammation. Finally, in vitro studies showed that GW9508 inhibited osteoclast formation and proinflammatory gene secretion from macrophages. In conclusion, this study demonstrated for the first time that GPR40/GPR120 agonist GW9508 reduced alveolar bone loss and alleviated periodontal inflammation in mice with MetS-exacerbated periodontitis, suggesting that activating GPR40/GPR120 with agonist GW9508 is a potential anti-inflammatory approach for the treatment of MetS-associated periodontitis.

Influence of file compression on radiographic diagnosis of periodontal bone loss on smartphones.

PURPOSE: To evaluate the influence of imaging compression on radiographic diagnosis of periodontal bone loss on smartphones. METHODS: 45 digital periapical radiographs with diverse periodontal bone loss patterns were selected. All radiographs were performed with a CMOS-type sensor and were exported from the acquisition software with two compressions: JPEG with a 10% compression rate and JPEG with a 90% compression rate. Images were shared using the WhatsApp application and three examiners evaluated all radiographs on the smartphone. The examiners' diagnostic agreement was evaluated using the Kappa index. The McNemar and Cochran's Q statistical tests were used to compare the impact of the image compression, examiner, and type of periodontal bone defect on the diagnosis. Statistical analysis was performed using the SPSS software. RESULTS: Kappa values were greater than 0.7 for all examiners and no statistically significant difference for the periodontal diagnosis, regardless of the image compression, the examiner background, and the type of periodontal bone defect. CLINICAL SIGNIFICANCE: The use of smartphones to analyze and share images has become very common in dentistry. This study shows that images can be shared and analyzed on smartphones without compromising periodontal diagnosis, regardless of their spatial resolution.

Consensus Report by the Italian Academy of Osseointegration on the Importance of Peri-Implant Soft Tissues.

Background and Objectives: The influence of the quantity and quality of peri-implant soft tissue on implant health and long-term maintenance is controversial. This consensus aimed to assess the importance of peri-implant soft tissue by analyzing four aspects: the role of keratinized mucosa (KM), the efficacy of specific collagen matrix, the influence of abutment material, and soft-tissue thickness. Materials and Methods: Active members of the Italian Academy of Osseointegration (IAO) participated in the consensus. Four systematic reviews were conducted, and their results were discussed to provide guidelines on the importance of soft tissue around implants. The first review evaluated the effect of KM on soft-tissue health, peri-implant bone loss, and patient-related variables. The second one analyzed if there was a specific type of matrix that provided better results in terms of peri-implant buccal soft-tissue thickness and keratinized mucosa width compared to autogenous soft-tissue graft. The third review evaluated the influence of different abutment materials on the soft tissues, and the fourth assessed the effect of soft-tissue thickness on peri-implant marginal bone loss (MBL). Results and Conclusions: The agreements reached by the assembly were as follows: the presence of supra-periosteal keratinized tissue is considered to favorably influence peri-implant health and aesthetics but had no relation to preventing bone crest resorption unrelated to infection. It facilitates patient cleaning around implants and reduces patient-reported pain. The free gingival graft (FGG) is considered the best in terms of supra-periosteal KM increase. Connective tissue grafts (CTG) perform better than volume-stable collagen matrices to increase soft-tissue thickness. Collagen matrices reduce surgical time and patient morbidity and can give better camouflaging. The influence of abutment material (titanium or zirconia) on MBL remains controversial, and no conclusion could be reached on this issue. Peri-implant soft-tissue health and recession seem not to be influenced by abutment material, but data are limited to zirconia and titanium. Although this systematic review highlighted the absence of a correlation between soft-tissue thickness and MBL, the assembly failed to find a consensus on this issue.

Effect of different implant positions for two implant-retained mandibular overdenture: a retrospective 5-years radiographic evaluation of the circumferential peri-implant bone loss and posterior ridge resorptive changes.

BACKGROUND: Studies did not recommend which position for implant overdenture poses the lowest biomechanical risk and the least chance of peri-implant bone loss and ridge resorption for those who might need a mandibular two-implant overdenture. The study objectives were to investigate the impact of implant position, in lateral incisors or canine positions, on peri-implant bone loss and posterior ridge resorption. METHODS: Fifty patients with mandibular two-implants were recalled and divided according to the implant position into two groups (group L: implants in lateral incisor positions and group C: implants in canine positions). The circumferential peri-implant bone level and posterior ridge resorption were assessed at implant insertion (T0), one year later (T1), and five years later (T5) using the follow-up CBCT. Data were analyzed using the Statistical Package of Social Science (SPSS) program. A Mann-Whitney test was used to compare two different groups. Paired groups were compared using the Wilcoxon signed-rank test. The threshold of significance is fixed at a 5% level (p-value). RESULTS: Significant differences in the vertical bone loss between groups appeared at (T5 - T1) (Mann Whitney test, (P = 0.01)) and at (T5 - T0) (Mann Whitney test, (P = 0.005)), and a significant difference in horizontal bone loss between groups was found at (T1 - T0) (Mann Whitney test, (P = 0.041)) and (T5 - T1) (Mann Whitney test, (P = 0.041)). Also, there were significant differences over the evaluation period between groups at certain points along the ridge at M1 (Mann Whitney test, (P = 0.021)), M3 (Mann Whitney test, (P = 0.008)), and M4 (Mann Whitney test, (P = 0.015)). CONCLUSIONS: According to the findings of this clinical study, the placement of implants in the lateral incisor position for two implant-retained overdentures is a viable choice. In comparison to the canine position, the lateral incisor position demonstrated superior peri-implant responses, which could potentially enhance the longevity of the implants. Furthermore, the placement of implants in the lateral incisor position can promote a more even distribution of stress and help mitigate posterior ridge resorption. Conversely, implants in the canine position may cause a seesaw effect and result in greater posterior ridge resorption. CLINICAL TRIAL REGISTRY NUMBER: (NCT06055842) (13/03/2024).

Effect of Densah Burs on Primary and Secondary Stability of Immediately Loaded Implants in Addition to Crestal Bone Loss and Gingival Probing Depth - An Evaluative Study.

INTRODUCTION: Osseodensification (OD) compaction increases primary stability by leaving the residual bone particles in the osteotomy site, which in turn act as an autograft. [ 1 ] Condensing the bone trabeculae through OD has demonstrated to have a potentiating influence on secondary stability. [ 2 ]. MATERIALS AND METHODS: A split-mouth study was conducted in 40 patients to determine the effect of OD on implant success rate in terms of primary and secondary stability in situations including immediate loading of implants placed in low-density bone, which was tested using resonance frequency analysis (RFA) at the interval of 0, 6 th month. In order to assess the implant success rate, gingival probing depth and crestal bone loss (CBL) around the implant were also assessed at baseline and 6 months. RESULTS: With respect to primary stability, at baseline, the mean RFA of Densah burs is 71.6 ± 9.5 and of conventional drills is 67.6 ± 10.4. The mean stability of Densah burs is significantly higher than conventional drills, both at baseline and after 6 months as well. CBL, at baseline, the mean CBL of Densah burs is 0.58 ± 0.11 and of conventional drills is 0.64 ± 0.12. The mean CBL of Densah burs is significantly lower than that of conventional drills for both. CONCLUSION: The implant stability values found in the present study were remarkable when compared between OD and conventional osteotomy techniques. Decreased loss of bone at the crest probing depth also aided in the increased success rate.

[Clinical effect of MB-PDT assisted initial therapy on alveolar angle absorption of lower anterior teeth].

PURPOSE: To evaluate the effect of MB-PDT assisted essential therapy on angle resorption of lower anterior alveolar bone in patients with periodontitis. METHODS: Forty patients who were diagnosed with periodontitis stage III-IV or C, lower anterior teeth alveolar bone angle resorption, and periodontal pocket depth greater than 4 mm were selected from April 2018 to October 2020 in the Department of Periodontology and Oral Mucosal Diseases, Changsha Stomatological Hospital. The patients were randomly divided into control group and experimental group with 20 cases in each group. Compared with the control group which was only managed with essential treatment, the experimental group was treated with MB-PDT on the basis of the control group. The plaque index (PLI) and gingival bleeding index (GBI) scores of the two groups were recorded before surgery and 1 and 2 weeks after surgery. Probing depth (PD) and clinical attachment level (CAL) were detected before and 6 months after surgery. Statistical analysis of the data was performed using Graphpad Prism 5 software package. RESULTS: The PLI and GBI of the experimental group were significantly lower than those of the control group at 1 and 2 weeks after operation(P＜0.05). Six months after surgery, PD and CAL levels in the experimental group were significantly lower than those in the control group (P＜0.05). CONCLUSIONS: MB-PDT adjuvant therapy has the advantages of simple operation, efficient sterilization, promotion of healing, and high safety performance. It may be a new non-surgical adjuvant treatment strategy for effective treatment of lower anterior alveolar angular resorption.

[Application of small intestinal submucosa absorbable biofilm in the repair of alveolar bone defects].

PURPOSE: To study the clinical efficacy of small intestinal submucosa (SIS) absorbable biological membrane in alveolar bone defect repair. METHODS: A total of 102 patients with alveolar bone defect who received guided bone regeneration (GBR) in our hospital from January 2020 to January 2022 were selected and divided into Bio-Gide group (51 cases using Bio-Gide absorbable biofilm) and SIS group (51 cases using SIS absorbable biofilm) by computer random number generator. The perioperative related indicators, blood calcium, blood phosphorus, biocompatibility, periodontal attachment loss (PAL) length, pulp sensitivity, tooth mobility, alveolar bone volume and adverse events of the two groups were compared. Statistical analysis was performed with SPSS 24.0 software package. RESULTS: There was no significant difference in operation time, intraoperative blood loss, visual analogue scale (VAS) score of pain on the first day after operation, VAS score on the fifth day after operation, wound healing time, blood calcium and phosphorus levels before operation, 1 d and 12 d after operation, PAL length before operation, 3 months, 6 months and 12 months after operation, pulp sensitivity and tooth looseness grade 1 and 2 percentage at 3, 6 and 12 months after operation, bone width increase, bone height increase at 12 months after operation and adverse event rate between the two groups (P＞0.05). Compared with Bio-Gide group, the wound healing time and biofilm absorption time were shortened in SIS group(P＜0.05), and the incidence of rejection was decreased 12 d after operation (P＜0.05). CONCLUSIONS: SIS absorbable biofilm and Bio-Gide absorbable biofilm have similar efficacy and safety in repairing GBR for alveolar bone defects, but the former is more biocompatible and the latter can provide longer barrier function.

Partial (incomplete) removal of granulation tissue using modified minimally invasive surgical technique in treatment of infrabony defects (randomized control clinical trial).

AIM: This study aims to compare the clinical and radiographic outcomes after complete versus incomplete removal of granulation tissue (GT) during modified minimally invasive surgical technique (M-MIST) for management of periodontitis patients with deep pockets associated with infra-bony defects. METHODOLOGY: Ten patients with a total of 14 deep non-resolving pockets (≥ 5 mm) associated with a vertical infra-bony defect were recruited for this study. They were randomized into 2 groups; a test group with incomplete removal of GT and a control group with complete removal of GT. Clinical parameters of clinical attachment level (CAL), residual probing depth (rPD) and buccal recession (Rec.) were recorded every 3 months. Radiographic periapicals were taken at baseline, 6 and 9 months. The significance level was set to 0.05. RESULTS: None of the results showed statistical significance between the 2 groups (p > 0.05). The test group showed less CAL gain (2 ± 0.87 mm, p = 0.062), more reduction in rPD (3.1 ± 0.96 mm, p = 0.017) and more recession (0.857 ± 0.26 mm, p = 0.017) than control group CAL gain (2.4 ± 0.58 mm, p = 0.009), rPD reduction (2.9 ± 0.3 mm, p = 0.001) and recession (0.5 ± 0.34 mm, p = 0.203) respectively. Control group had linear reduction in depth defect (DD) (0.68 ± 0.287, p = 0.064) compared to an increase in DD in test group (-0.59 ± 0.5, p = 0.914). CONCLUSIONS: No statistical significance were observed in healing parameters between complete removal of GT in M-MIST and incomplete (partial) removal of GT of deep pockets with infra-bony defects both clinically and radiographically. Further studies with larger samples are needed to confirm the results.