The adjunctive effect of polydeoxyribonucleotide on bone formation in alveolar ridge preservation: A pre-clinical in vivo study.

AIM: This study investigated the adjunctive effect of polydeoxyribonucleotide (PDRN) on bone formation in alveolar ridge preservation (ARP) sockets. MATERIALS AND METHODS: Both mandibular second, third and fourth premolars of eight beagle dogs were randomly divided into ARP and ARP/PDRN groups. Following tooth extraction, ARP procedures were conducted using collagenized alloplastic graft material and bilayer collagen membrane soaked with normal saline (ARP group) or PDRN (ARP/PDRN group) for 10 min before application. Both groups were also randomly allocated to 2-, 4- or 12-week healing subgroups. The primary endpoint of this study was to compare histomorphometric differences between ARP and ARP/PDRN. The secondary endpoints of this study were to compare micro-CT analysis and three-dimensional volumetric measurement between the two groups. RESULTS: In the histomorphometric analysis, the ARP/PDRN group exhibited greater new bone formation at coronal, middle and total position compared with the ARP group at 2-week healing. The number of newly formed blood vessels was higher in the ARP/PDRN group than in the ARP group at 2- and 4-week healing. In micro-CT analysis, the mean new bone volume/total bone volume between ARP and ARP/PDRN was statistically significant at 2-week healing. Ridge volume alterations were significantly decreased in the ARP/PDRN group during entire healing time compared with the ARP group, especially on the buccal side. CONCLUSIONS: The application of PDRN in ARP might provide additional benefits for early bone regeneration and maintenance of buccal ridge volume.

Diagnostic performance of a point-of-care test device for periodontitis using human saliva: a single-center, single-blinded, confirmatory study.

OBJECTIVE: Recently, matrix metalloproteinase-8 (MMP-8) has been used to diagnose periodontal disease in a point-of-care (POC) test in order to save time and cost relative to the traditional diagnostic workflow. This study aimed to investigate the diagnostic performance of INCLIX TRF MMP-8, a POC testing device for periodontitis using the area under the receiver operating characteristic curve, sensitivity, specificity, and predictive values. MATERIALS AND METHODS: Full-mouth periodontal examination and radiographic analysis were used for evaluating periodontal condition based on the 2018 classification of periodontal disease. A dichotomous diagnosis of clinical periodontal condition was performed using the POC device. The relationships among periodontal condition and the concentration of MMP-8, tooth loss (TL), gingival index (GI), plaque index (PI), and alveolar bone loss (ABL) were assessed by the Spearman rank correlations (rs). RESULTS: In all, 108 cases of non-periodontitis (NP) and 191 cases of periodontitis (P), including 38 cases of periodontitis stage I, 42 cases of periodontitis stage II, 99 cases of periodontitis stage III, and 11 cases of periodontitis stage IV, were enrolled in this study. Diagnostic accuracy in assessing periodontal condition with the POC device improved when it was used with participants aged ≥ 40 years. There were weak positive correlations between periodontal condition and MMP-8 and between periodontal condition and GI (rs2 = 0.1124 and rs2 = 0.0906, respectively), whereas a strong positive correlation between periodontal condition and alveolar bone loss (rs2 = 0.6877) was observed. CONCLUSION: The POC device investigated in this study is a potential tool to distinguish between NP and P in individuals ≥ 40 years of age.

Minimally Invasive Regenerative Surgery by Peri-implant Excision and Regenerative Surgery (PERS) in Peri-implantitis: One-year Result on Three Cases.

This case series presents three patients undergoing minimally invasive regenerative surgery for peri-implantitis using peri-implant excision and regenerative surgery (PERS). No report of a resolved inflammatory state with peri-implant bone loss following nonsurgical treatment was included in this case report. After the suprastructure of the implant was disconnected, a peri-implant circular incision was made to remove inflammatory tissue. The combination decontamination method was conducted using a chemical agent and a mechanical device. After copious irrigation with normal saline, collagenated demineralized bovine bone mineral was applied to fill the peri-implant defect. The suprastructure of the implant was connected following the PERS procedure. The three patients with peri-implantitis that underwent successfully PERS procedures suggest that surgical intervention is a feasible approach to obtaining proper peri-implant bone filling of 3.42 ± 1.08 mm. However, this novel technique should be investigated in a larger sample size to determine its reliability and validity.

A randomized controlled trial of immediate implant placement comparing hydroxyapatite nano-coated and uncoated sandblasted/acid-etched implants using a digital surgical guide.

PURPOSE: This study evaluated the implant stability, volumetric changes, and patient-reported outcome measures (PROMs) of hydroxyapatite (HA) nano-coated sandblasted/acid-etched (SLA) implants compared to uncoated SLA implants. METHODS: Forty patients were recruited and randomly allocated to HA nano-coated SLA group (test, n = 20) and uncoated SLA group (control, n = 20) using single-blinded/block randomization. Implants were immediately placed in maxillary posterior region using a digital surgical guide. Insertion torque and implant stability quotient (ISQ) were measured at implant surgery and 1, 2, 3, and 4 months postoperatively. Intraoral scans, PROMs and soft tissue inflammation data were collected, and multivariable linear regression analysis of ISQ was performed. RESULTS: In total, 48 implants (test; n = 24, control; n = 24) in 37 patients (test; n = 19, control; n = 18) were analyzed. Despite no significant between-group difference at surgery, the test group showed higher ISQ values than the control group at 2 (76.53 ± 4.17 vs. 71.32 ± 4.79, p < 0.01), 3 (77.45 ± 4.41 vs. 73.85 ± 4.69, p < 0.05), and 4 months (79.08 ± 2.96 vs. 73.43 ± 3.52, p < 0.0001) postoperatively. There were no significant differences in linear and volumetric changes, PROMs, and soft tissue inflammation analysis between two groups. The ISQ at implant surgery was influenced by age and diabetes mellitus (DM) at the implant level and DM and predicted total bone-to-implant contact area at the patient level. CONCLUSION: HA nano-coated SLA implants promoted favorable immediate implants stability during early osseointegration phase compared to uncoated SLA implants, but displayed similar dimensional changes, PROMs, and soft tissue inflammation outcomes. TRIAL REGISTRATION: Clinical Research Information Service (CRIS), KCT0006364. Registered 21 July 2021, https://cris.nih.go.kr/cris/search/detailSearch.do?seq=24221&search_page=L .

Preclinical comparison study of experimental peri-implantitis between alveolar ridge preservation and spontaneous healing sites in infected and noninfected tooth: a randomized blinded in vivo study.

BACKGROUND: This study compared the progression of experimental peri-implantitis between alveolar ridge preservation (ARP) and spontaneous healing (SH) sites in infected (IT) and noninfected tooth (NIT). METHODS: Bilateral mandibular third or fourth premolars of six beagle dogs were randomly assigned to IT and NIT groups. Before extraction, chronic dehiscence defects were created at the mesial root of mid-buccal area in IT group. Four weeks later, the mesial roots of the third and fourth premolars were extracted in all groups.ARP procedure was randomly conducted on one side of the extraction sockets using collagenated bovine bone substitutes and resorbable collagen membrane, and contralateral side was allowded spontaneous healing. After 12 weeks of healing, bone-level implants (ϕ 3.6 × 8.0 mm) were placed at the extraction sockets. Three months of ligature induced peri-implantitis and three months of spontaneous progression were allowed, with radiographs taken at each phase. Biopsies were retrieved at the implant site for histomorphometric, immunohistochemical, and polarized light-microscopic analyses. RESULTS: Radiography demonstrated that the changes in the marginal bone level during the spontaneous progression period showed no significant differences between ARP and SH sites. Only small and/or nonsignificant differences in the progression of peri-implantitis were observed between ARP and SH sites in histomorphometric, immunohistochemical, and polarized light microscopic analyses. Additionally, the IT and NIT groups exhibited similar outcomes for most parameters. CONCLUSION: ARP with xenogenic bone substitutes might provide similarly robust results as SH sites regarding the progression of experimental peri-implantitis, irrespective of the infected or noninfected nature of the site before tooth extraction.

Clinical evaluation of implants placed within or beyond the boundaries of the alveolar ridge preservation: a retrospective case series with 10 weeks of observations in 28 patients.

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.

Does defect configuration affect the outcomes of alveolar ridge preservation? An experimental in vivo study.

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.

Progression of experimental peri-implantitis in guided bone regeneration and pristine bone: A preclinical in vivo study.

BACKGROUND: Guided bone regeneration (GBR) is the most widely used technique for overcoming the deficiency of alveolar bone. However, the progression of peri-implantitis in regenerative and pristine bone sites has not been fully investigated. The aim of this study is to compare experimental peri-implantitis around implants placed in pristine bone and GBR sites. METHODS: Bilateral  mandibular first molars were extracted from six beagle dogs, and standardized horizontal ridge defect was simultaneously created at predetermined site in unilateral mandible. After 8 weeks, guided bone regeneration procedure was conducted at the defect site. After 16 weeks, implants (ϕ 3.6×8.0 mm) were placed at both extracted sites. This study included 3 months of active breakdown and another 3 months of spontaneous progression period. Radiographs were taken at each phase and specimens were obtained for histological, immunohistochemical, and polarized light microscopic analysis. RESULTS: Marginal bone loss around implant did not show the significant differences between pristine bone and GBR sites during spontaneous progression period. In immunohistochemical analysis, inflammatory and immune-related cells were predominantly detected in peri-implantitis-affected area rather than unaffected area. In the polarized light microscopic analysis, substantial reductions in the amount and thickness of collagen fibers were observed in peri-implantitis-affected area compared with unaffected tissues. However, there were no significant differences in histological, immunohistochemical, polarized light microscopic outcomes between pristine bone and GBR sites. CONCLUSION: Previous hard tissue grafting at the implant sites did not affect experimental peri-implantitis and exhibited similar radiographic, histological, immunohistochemical, and polarized light microscopic outcomes compared with those of pristine bone sites.

Risk factors impacting the survival of implants replaced following failure: A retrospective study.

AIM: This study aimed to investigate factors influencing the survival of replaced dental implants. MATERIALS AND METHODS: Charts from 2005 to 2021 were reviewed. Replaced implants after removal for the first time were identified. Depending on their survival, the replaced group was divided into the surviving and second-removal groups. Risk factors affecting survival of replaced implants were evaluated considering clustering of multiple implants within patients. RESULTS: The present study included 464 replaced implants of 370 patients, of which 429 and 35 implants were categorized into the surviving group and the second-removal group. The 5-year survival rate was 90.2 ± 0.18% in replaced implants at sites with a periodontitis history and 97.0 ± 0.15% at sites without a periodontitis history (p = 0.008). The 5-year survival rate was 89.1 ± 0.27% in replaced implants with guided bone regeneration (GBR) at first implant placement and 93.9 ± 0.14% at non-GBR (p = 0.032). The 5-year survival rate was 97.6 ± 0.13% in replaced implants with GBR and 90.3 ± 0.17% in replaced implants without GBR (p = 0.026). In the multivariable analysis adjusted for clinical variables, periodontitis history (adjusted hazard ratio [aHR] = 3.417; 95% confidence interval [CI] = 1.161-10.055), GBR at first implant placement (aHR = 2.152; 95% CI = 1.052-4.397) and non-GBR at primary implant replacement (aHR = 0.262; 95% CI = 0.088-0.778) were identified as independent risk factors for second implant removal. CONCLUSIONS: Periodontitis history, GBR at first implant placement and non-GBR at primary implant replacement were identified as risk factors affecting the survival of replaced implants.