Purpose: We examined the progression of experimental peri-implantitis in sites that underwent either alveolar ridge preservation (ARP) or spontaneous healing (SH), comparing infected teeth (IT) and non-infected teeth (NIT). This investigation is a secondary analysis of a preclinical study aimed at exploring the correlation between newly formed bone and implant stability quotient (ISQ), as well as the association between newly formed bone and the progression of experimental peri-implantitis. Methods: The bilateral mandibular third or fourth premolars of 6 beagle dogs were randomly assigned to 4 groups: IT/SH, IT/ARP, NIT/SH, and NIT/ARP. Following implant placement, core biopsies were retrieved from each site, and the ISQ value was measured. A 3-month period was allowed for peri-implantitis induction, followed by an additional 3 months for the spontaneous progression of peri-implantitis, with radiographs taken at each time point. Results: During the spontaneous progression of peri-implantitis, no statistically significant differences were observed among the groups in terms of mean ISQ values and radiographic marginal bone loss. Similarly, the percentages of bone substitute, newly formed bone, and fibrovascular connective tissue in core biopsies did not differ significantly among the groups.Linear regression analysis revealed no significant linear correlation between newly formed bone and ISQ in any group (P>0.05). However, a weak linear correlation between newly formed bone and marginal bone loss during the spontaneous progression of peri-implantitis was noted in the IT/SH group alone (P=0.036). Conclusions Within the limitations of this study, we were unable to demonstrate that ARP could improve newly formed bone or primary implant stability. Furthermore, neither ARP nor SH significantly influenced the spontaneous progression of experimental peri-implantitis.

Purpose: Root coverage (RC) procedures require long-term evaluation. This study assessed the clinical validity and long-term stability of a modified tunneling technique for lower anterior gingival recession (GR) using a subepithelial connective tissue graft (SCTG) and a volume-stable collagen matrix. Methods: Across 39 patients, 66 mandibular incisors with ≥1.0 mm of GR were examined before and after RC surgery. Clinical photographs documenting the results of RC were taken at baseline (T0 ) and the most recent follow-up visit (T l ). Impressions were obtained either at baseline (T0 ) or 3 weeks later (T 3 ). The recession depth, Miller classification, and rates of RC and complete root coverage (CRC) were assessed. Results: This study analyzed 66 GR sites across 39 patients, with an average follow-up period of 41.3 months. Overall, the mean RC achieved was 86.2%±15.7%. Among single recessions, the RC was 85.2%±25.6% for Miller class I, 91.5%±10.4% for class II, and 79.2%±18.3% for class III. Regarding multiple recessions, the RC was 85.1%±16.2% for Miller class I, 87.0%±12.5% for class II, and 89.8%±16.0% for class III. By Miller classification, the RC was 85.1%±16.8% for class I, 88.7%±11.6% for class II, and 85.8%±17.3% for class III.Furthermore, the RC varied by follow-up duration: 72.5%±15.1% at 12 months, 90.1%±12.6% at 25–36 months, 89.0%±16.7% at 37–48 months, 91.10%±9.88% at 49–60 months, and 97.6±4.79% for longer than 61 months, with 77.8% of the last group achieving CRC. RC also differed based on the initial recession depth, at 88.0%±16.8% for 1–3 mm, 83.1%±14.1% for 3–6 mm, and 80.2%±5.04% for depths exceeding 6 mm. Conclusions A modified tunneling technique, utilizing SCTG and a volume-stable collagen matrix, appears to represent a reliable option for the long-term management of GR in the lower anterior region, even in cases involving multiple Miller class III GRs.

Purpose: The identification of specific target molecules and their appropriate cut-off values is crucial for the successful development of in vitro diagnostics. Salivary biomarkers, such as interleukin-1β (IL-1β) and matrix metalloproteinase-8 (MMP-8), have been investigated for their potential in diagnosing periodontal disease. This study aimed to evaluate the efficacy of IL-1β and MMP-8 as diagnostic tools and to establish their cut-off values for distinguishing active types of periodontal disease from healthy conditions. Methods: We conducted a prospective cohort study involving 47 participants, who were divided into 2 groups: the control group consisted of 24 individuals with healthy or mild periodontal conditions (stages I–II of periodontal disease), and the periodontal group comprised 23 individuals with moderate to severe periodontal disease (stages III–IV). Saliva samples were collected from all participants, followed by an oral examination, periodontal charting, and radiographic assessments. The salivary concentrations of IL-1β and MMP-8 were quantified using enzyme-linked immunosorbent assays. Results: Significant differences in salivary levels of IL-1β and MMP-8 were observed between the control group and those with periodontal disease. However, after adjusting for age and sex, these differences were not statistically significant for IL-1β. In contrast, the differences remained significant for MMP-8 in participants classified as having an active type of periodontal disease, specifically those in the periodontal group with more than 10% bleeding on probing. By setting a cut-off value of 200 ng/mL for salivary MMP-8, the sensitivity and specificity for diagnosing active periodontal disease were determined to be 70% and 86.5%, respectively. Conclusions Our findings indicate that salivary MMP-8, using a cut-off value of 200 ng/ mL, serves as a reliable biomarker for identifying active periodontal disease. This biomarker holds potential for further development into a diagnostic tool in in vitro settings, which could improve the early detection and management of periodontal disease.

Purpose: This study investigated the effect of implant vertical positioning within alveolar ridge preservation (ARP) sites on implant stability quotient (ISQ) values, which were measured 10 weeks post-implantation. Methods: Patients who underwent ARP using collagenized deproteinized bovine bone mineral, followed by implant placement in the posterior area, were divided into 2 groups:the within-ARP group and the beyond-ARP group. In the within-ARP group, osteotomy and implant placement occurred within the ARP boundary. In contrast, in the beyond-ARP group, these procedures were performed beyond the ARP boundary, incorporating 3 mm of pristine bone at the implant’s apex. Bone quality was assessed by tactile sense, and both insertion torque during implant surgery and ISQ values at 10 weeks post-implant surgery were measured. Multiple linear regression analysis and Pearson correlation analysis were used to explore the relationship between insertion torque and ISQ values. Results: In total, 30 ARP sites in 28 patients were analyzed. There was no significant difference in bone quality, as determined by tactile sense, between the within-ARP and beyond-ARP groups. At the time of implant placement, the beyond-ARP group exhibited a higher insertion torque (33.33±13.39 Ncm) compared to the within-ARP group (17.08±11.17 Ncm). However, the ISQ values were similar between the 2 groups 10 weeks after implant placement. A positive correlation between insertion torque and ISQ values was confirmed at 10 weeks post-implant. Conclusions The engagement of pristine bone may facilitate high insertion torque during the placement of implants in ARP sites. Nevertheless, by 10 weeks post-implantation, the ISQ values were found to be comparable, irrespective of the implant’s position.

Purpose: The purpose of this study was to compare the bone healing potential of 1-, 2-, and 3-wall defects following alveolar ridge preservation (ARP) treatment, as well as to evaluate the efficacy of ARP as a treatment option for destructive sites. Methods: Three groups, characterized by 1-, 2-, and 3-wall defects, were randomly assigned to the maxillary second, third, and fourth premolars in each of 8 beagle dogs. Each defect was created at either the mesial or distal root site of the tooth, which was hemi-sectioned and extracted. The contralateral root was preserved to superimpose with the experimental site for histomorphometric analysis. For each site, either spontaneous healing (SH; control) or ARP (test intervention) was randomly applied. Each group was divided in half and underwent a healing period of either 4 or 12 weeks. The Mann-Whitney U test and Kruskal-Wallis test were used for histomorphometric analyses. Statistical significance was set at P<0.05. Results: Qualitative analysis revealed a higher percentage of new bone in the apical area compared to the coronal area, regardless of defect type and healing period. In quantitative analysis, the 3-wall defect exhibited a significantly higher percentage of mineralization in the ARP group after 12 weeks of healing (ARP: 61.73%±7.52%; SH: 48.84%±3.06%; P=0.029).An increased percentage of mineralization was observed with a greater number of remaining bony walls, although this finding did not reach statistical significance. Conclusions Within the limitations of this study, ARP treatment for compromised sockets appears to yield a higher percentage of mineralization compared to SH. Although the effectiveness of the remaining bony walls was limited, their presence appeared to improve the percentage of mineralization in ARP treatment.

Purpose: This study aimed to analyze the bone regeneration and biosorption patterns of different bone substitutes in a rabbit skull defect model. Methods: Four circular 8 mm-defects were created in the cranium of 12 New Zealand white rabbits, each weighing approximately 3 kg. Each defect was randomly assigned to one of 4 treatment groups: cortical deproteinized porcine bone mineral (DPBM), cancellous DPBM, biphasic calcium phosphate (BCP) with a 6:4 ratio of hydroxyapatite (HA) to β-tricalcium phosphate (β-TCP) (TCP4), and BCP with a 2:8 ratio of HA to β-TCP (TCP8). The rabbits were euthanized at either 6 weeks (n=6) or 12 weeks (n=6) post-surgery. The harvested specimens were then analyzed both radiographically and histomorphometrically. Results: In the micro-computed tomography analysis, no statistically significant differences were observed among the 4 groups, except in the bone graft volume/tissue volume (GV/TV) at 12 weeks. Cortical DBPM exhibited a higher GV/TV ratio than cancellous DBPM at the same time point. The histomorphometric analysis revealed increased biosorption in cancellous DBPM compared to cortical DBPM at 12 weeks. However, the percentage of newly formed bone did not significantly differ among the 4 groups. Conclusions All types of bone substitutes demonstrated similar patterns of bone regeneration at both 6 and 12 weeks of observation. However, cancellous DPBM exhibited a higher rate of bioabsorption compared to other bone substitutes, suggesting that it may have different indications or applications in guided bone regeneration protocols.

Purpose: Endosseous titanium dental implants are widely regarded as the gold standard for replacing missing teeth. Despite the proven osseointegration of titanium implants, particularly those with enhanced surface modifications, concerns remain regarding esthetics, the risk of peri-implantitis, and potential hypersensitivity. Consequently, alternative materials, such as zirconia, have received increasing attention in recent years. This study evaluated the osseointegration parameters of zirconia implants placed in the mandibles of beagle dogs, as a preliminary in vivo evaluation of zirconia dental implants in South Korea. Materials and Methods: Seven 8-month-old beagle dogs underwent premolar extraction followed by placement of implants in the healed mandibular ridges. The following implants were used in this study: six turned-surface titanium implants, six rough-surface titanium implants, and six zirconia implants, following which the implants and surrounding tissues were harvested en bloc for histological analyses. Bone-to-implant contact (BIC) and new bone area (BA) percentages (%) were calculated and compared between the groups. Statistical analyses were conducted using ANOVA, with the significance level set at p < .05. Results: Histological analysis revealed no statistically significant difference in BIC between the rough-surface titanium and zirconia implants, although the turned-surface titanium implants exhibited significantly lower BIC than the other two groups (p < .05). No significant differences were found among the three groups in terms of BA. Conclusion The results of this study demonstrate that zirconia implants achieve BIC comparable to that of rough-surface titanium implants, suggestive of their potential clinical application.

Purpose: This study aimed to evaluate the long-term cumulative survival rate (CSR) of dental implants with micro-threads in the neck over a 10-year follow-up period and to examine the factors influencing the survival rate of dental implants. Methods: This retrospective study was based on radiographic and dental records. In total, 151 patients received 490 Oneplant ® dental implants with an implant neck micro-thread design during 2006–2010 in the Department of Periodontology of Seoul National University Dental Hospital. Implant survival was evaluated using Kaplan–Meier analysis. Cox proportional hazard regression analysis was used to identify the factors influencing implant failure. Results: Ten out of 490 implants (2.04%) failed due to fixture fracture. The CSR of the implants was 97.9%, and no significant difference was observed in the CSR between externaland internal-implant types (98.2% and 97.6%, respectively,P=0.670). In Cox regression analysis, 2-stage surgery significantly increased the risk of implant failure (hazard ratio: 4.769, P=0.039). There were no significant differences in influencing factors, including sex, age, implant diameter, length, fixture type, location, surgical procedure, bone grafting, and restoration type. Conclusions Within the limitations of this retrospective study, the micro-thread design of the implant neck was found to be favorable for implant survival, with stable clinical outcomes.