Young Ku

Background: This prospective observational study evaluated three-dimensional soft tissue contour changes over a 90-day healing period following bilateral premolar extractions, with and without alveolar ridge preservation (ARP), using intraoral scanning and 3D digital analysis. Methods: Eighteen orthodontic patients requiring bilateral premolar extractions were enrolled. In each patient, the extraction socket with relatively lower buccal bone height was assigned to alveolar ridge preservation (ARP), while the contralateral site was left to heal spontaneously. Intraoral scans were obtained immediately before extraction and at 30 days and 90 days post-extraction. Linear horizontal soft tissue changes were measured at 2 mm (H2) and 4 mm (H4) below the gingival margin, while vertical changes were assessed at the central aspect of the extraction socket. Surface displacement was analyzed using root mean square (RMS) distance, and volumetric changes were quantified using region-of-interest segmentation. Results: Significant time-dependent changes in soft tissue contours were observed (p < .001), with greater horizontal reduction at H2 than H4, and more pronounced buccal changes (p < .05). At day 90, mean horizontal reduction at H2 buccal was 1.84 ± 0.69 mm (ARP) and 1.72 ± 0.68 mm (control); corresponding H2 lingual reductions were 1.34 ± 0.89 mm and 1.16 ± 0.29 mm. Vertical reduction peaked at 30 days with partial recovery by day 90. RMS-based displacement was greater buccally. Volumetric reduction was approximately 17% in both groups. No statistically significant differences were found between groups. Conclusions: Intraoral scanning combined with digital superimposition proved effective for evaluating soft tissue changes after extraction. While ARP remains a valuable approach for alveolar bone preservation, its additional impact on soft tissue contour was limited in sites with favorable baseline conditions. Trial registration: Clinical Research Information Service (CRIS), KCT0010923. Registered 19 August 2025. Retrospectively registered.

This report presents two cases demonstrating long-term tooth preservation through supportive periodontal therapy (SPT) following active treatment. Case 1 involved a 44-year-old female diagnosed with generalized Stage III periodontitis in 1988, who underwent comprehensive non-surgical and surgical treatment followed by individualized SPT for 35 years, totaling 169 recall visits. Except for one molar, all teeth remained stable. Case 2, a 41-year-old female diagnosed in 2008 with generalized Stage III periodontitis and advanced bone loss, received repeated non-surgical therapy with adjunctive doxycycline, successfully delaying multiple extractions for over 10 years until selective implants were placed. Both patients showed excellent compliance and received adjunctive interventions when indicated. These cases highlight the critical role of individualized SPT in preventing recurrence, maintaining periodontal stability, and extending tooth survival in periodontally compromised patients through periodic evaluation, risk-factor control, and continuous reinforcement of oral hygiene.

Ryoo KS, et al. J Periodontal Implant Sci. 2023 Nov;53:e51. https://doi.org/10.5051/jpis.2302400120

Nam DH, et al. J Periodontal Implant Sci. 2023 May;53:e18. https://doi.org/10.5051/jpis.2203240162

Ryoo KS, et al. J Periodontal Implant Sci. 2023 Mar;53:e8. https://doi.org/10.5051/jpis.2203340167

Kim YJ, et al. J Periodontal Implant Sci. 2022 Oct;52(5):351-351. https://doi.org/10.5051/jpis.225205edi01

Background and Purpose The purpose of this study was to assess the occurrence and prognosis of dental implant proximity or direct contact with the adjacent tooth and to evaluate the symptoms and complications in both the implant and the adjacent tooth. We then elaborate on treatment modalities and discuss the prevention of this phenomenon. Materials and Methods This retrospective study was conducted based on the dental clinical and radiographic records of 43 patients with implant-tooth proximity of In the multivariate regression analysis, the rate of occurrence of tooth symptom decreased by about 95% with every increase of 1.0 mm distance between implant and tooth (odds ratio [OR] = 0.1, 95% confidence interval [CI]: 0.004-0.680, p = 0.024). In the case of implant-tooth root proximity in the anterior area, the OR of peri-implantitis occurrence was 30.4-fold greater than in posterior sites (OR = 30.4, 95% CI: 1.189-785.914, p = 0.040). Conclusion Implant-tooth root proximity or direct implant-tooth contact is an iatrogenic factor that causes various complications, including devitalization of the adjacent tooth and peri-implantitis. Proactive prevention with surgical stents and intra-operative periapical radiographs is needed. If proximity or contact is found during surgery, repositioning of the fixture to the correct location is recommended in order to maintain peri-implant health and prevent complications.

Cho YD, et al. J Periodontal Implant Sci. 2022 May;52:e9. https://doi.org/10.5051/jpis.2103760188

Background and purpose: Significant research and development (R&D) has been conducted to make the best dental implants while developing various patent applications and registrations. In this study, we evaluated the current status of patents on dental implants and identified the future direction of R&D progress.Materials and methods: A total of 29 711 patents related to dental implants were reviewed. These were published between 1909 and 2020 and retrieved from the Derwent Innovation patent database. The patents were grouped into three categories depending on the implant components: fixture, abutment, and artificial teeth.Results: The category with most patents was “abutment,” and the most cited patent was “screw‐type dental implant anchor.” Global patenting trends over the past 20 years showed that both applicants and applications increased in the early 2010s; however, these have since been on the decline. Currently, the United States holds the largest number of patents, and Nobel Biocare Holding AG is the top assignee. Technic maturation prediction analysis showed that the current dental implant technology is in the “decline stage.”Conclusion: Trend analysis of the dental implant patent indicates the main contributors of development are profit‐oriented companies. Recent reduction in the number of new patent applications suggests the technology is in the mature declining stage. The emergence of new materials or technologies that may close the gap in clinical unmet needs would reverse the trend.