This study evaluated immunohistochemical profiles associated with guided bone regeneration (GBR) using collagen membranes with different thickness-related mechanical properties to characterize membrane-related biological responses during lateral bone augmentation. Standardized mandibular defects in beagle dogs were grafted with bone substitutes and covered with one of two collagen membranes with different thickness-related mechanical properties or left uncovered. At 8 and 16 weeks, tissues were analyzed for markers associated with osteogenesis (ALP), vascular/perivascular and myofibroblast-associated responses (α-SMA), inflammation-related cell profiles (iNOS and CD206), and bone remodeling (TRAP, Cathepsin K, and collagen type I). At 8 weeks, the FM group showed a trend toward higher numbers of CD206-positive cells in the coronal region. iNOS-positive cells did not differ significantly among groups in any region. However, most macrophage-related outcomes were not statistically significant. The SM group exhibited significantly greater collagen type I deposition, particularly in deeper regions, although this appeared to represent early unmineralized matrix rather than enhanced bone formation. TRAP-positive cells were more frequently observed in membrane-covered groups at both time points, mainly around biomaterials, suggesting remodeling-related activity. ALP, α-SMA, and Cathepsin K showed no significant intergroup differences. At 16 weeks, most immunohistochemical differences had diminished across all groups. Collagen membranes with different thickness-related mechanical properties were associated with distinct early tissue responses during GBR healing. The FM group showed trends toward increased CD206-positive cells, whereas the SM group exhibited greater early collagen type I deposition. Because most inflammation-related outcomes were not statistically significant, these findings should be interpreted cautiously and considered exploratory.

OBJECTIVES:Peri-implantitis is a common biological complication of dental implant therapy that affects peri-implant tissues as well as patients' psychological well-being and oral health-related quality of life. This review summarizes patient-centered perspectives on peri-implantitis, focusing on patient perception at diagnosis, treatment experiences, and treatment-related discomfort. MATERIALS AND METHODS:A narrative review of the literature was conducted to identify studies addressing patient perceptions, emotional responses, and patient-reported outcomes related to peri-implantitis management. Evidence from qualitative studies, cross-sectional investigations, and clinical trials reporting patient-centered outcomes was evaluated. RESULTS:The literature shows that peri-implantitis often progresses with minimal or no subjective symptoms, resulting in a discrepancy between clinical findings and patient awareness at diagnosis. Disclosure of the diagnosis is frequently associated with anxiety, stress, and concerns regarding implant prognosis and treatment burden. During treatment, patients commonly anticipate considerable pain and invasiveness; however, actual treatment-related discomfort is generally mild to moderate and transient, with postoperative pain peaking early and resolving within a short period. Patient experiences are strongly influenced by the clarity of diagnostic explanations, expectation management, and the quality of clinician-patient communication. CONCLUSIONS:Peri-implantitis has a measurable psychosocial impact beyond clinical parameters. Patient perceptions at diagnosis and during treatment play a key role in treatment acceptance and adherence. CLINICAL RELEVANCE:Many patients are diagnosed with peri-implantitis without prior awareness of the disease. Clear communication regarding diagnosis, expected treatment-related discomfort, and prognosis may reduce anxiety, improve treatment acceptance, and support long-term maintenance care.

Preclinical animal models are essential for evaluating the biological performance, safety, and translational potential of bone regeneration strategies before human application. Because no single species can fully replicate human skeletal biology, careful selection of an appropriate model is necessary to generate reliable and clinically meaningful evidence. This narrative review summarizes the characteristics, advantages, and limitations of commonly used experimental species, with particular emphasis on their anatomical and biomechanical similarity to humans and their suitability for modeling localized and systemic bone-healing conditions. Rodent models are widely used for early-stage screening because they are cost-effective, genetically manipulable, and well-suited for mechanistic studies. However, their limited cortical thickness, strong intrinsic healing capacity, and lack of true Haversian remodeling reduce their translational applicability for evaluating large defects or load-bearing sites. Rabbit models provide an intermediate platform for testing medium-sized defects, with more clearly defined critical-size thresholds and partial Haversian remodeling. Dogs offer clinically realistic surgical handling, human-like bone remodeling, and the ability to standardize complex intraoral defects, although their use is declining because of ethical and regulatory considerations. Minipigs and pigs show the closest correspondence to human craniofacial bone structure, density, and biomechanics, making them highly valuable for late-stage translational validation. However, their strong healing potential and large body size require carefully standardized defect designs and rigorous experimental controls. Across all species, acute versus chronic defects, infected versus noninfected environments, and systemically healthy versus compromised conditions substantially influence healing outcomes. Standardized defect dimensions, appropriate observation periods, and robust quantitative assessment methods are critical for ensuring reproducibility. An understanding of species-specific healing patterns and methodological considerations enables investigators to design preclinical experiments that more closely reflect clinical scenarios and support the development of predictable regenerative therapies.

PURPOSE:This study evaluated phase-specific peri-implant marginal bone level (MBL) changes associated with abutment disconnection and reconnection during prosthetic procedures by comparing implant-level (IL) and abutment-level (AL) restorative protocols over a 1-year period. METHODS:This two-arm randomized controlled clinical trial included patients receiving posterior mandibular fixed partial dentures following soft tissue augmentation. Implants were randomly assigned (1:1) to IL or AL protocols. In the IL group, repeated abutment disconnection and reconnection were performed during prosthetic procedures, whereas in the AL group, a definitive abutment was connected and maintained without disconnection. Standardized periapical radiographs were obtained at implant placement (T0), 2 weeks after second-stage surgery (T1), at definitive prosthesis delivery (T2), and 1 year after loading (T3). MBL changes were analyzed by phase: suprastructure connection (T1-T0), prosthetic (T2-T1), maintenance (T3-T2), and cumulative (T3-T0). Statistical significance was set at P<0.05. RESULTS:Implant success was 100% at 1 year in both groups. In the IL group, MBL changes were Δ(T1-T0)=-0.41±0.43 mm, Δ(T2-T1)=-0.34±0.38 mm, and Δ(T3-T2)=-0.31±0.43 mm, with a cumulative change of Δ(T3-T0)=-1.06±0.49 mm. In the AL group, the corresponding values were -0.81±0.44 mm, -0.14±0.24 mm, -0.12±0.30 mm, and -1.08±0.39 mm, respectively. Phase-specific remodeling differed between protocols, whereas the cumulative 1-year change was comparable. CONCLUSIONS:Under conditions of vertical soft tissue augmentation, abutment disconnection and reconnection were associated with phase-specific MBL remodeling; however, cumulative 1-year MBL changes were similar between IL and AL protocols.

OBJECTIVE:This study evaluated the 5-year survival of bone-level, internal connection, sandblasted and acid-etched (SA) implants and identified site- and patient-related risk factors for implant failure in a multicenter cohort. MATERIALS AND METHODS:A total of 3555 tapered bone-level SA implants were placed between 2012 and 2018 at two university dental hospitals. The observation period spanned from placement to removal or the last follow-up (final date: May 15, 2025). Survival outcomes were analyzed using Kaplan-Meier estimates and Cox regression with shared frailty terms to adjust for clustering within patients. RESULTS:The 5-year cumulative survival rate was 98.8% at the implant level and 99.0% at the patient level. Tooth loss due to periodontitis significantly increased implant failure risk (adjusted HR 3.57, 95% CI: 1.49-8.54, p < 0.01). Implants placed without guided bone regeneration (GBR) had a lower risk of failure than those with GBR (adjusted HR 0.42, 95% CI: 0.18-0.96, p = 0.04). Supportive periodontal therapy (SPT) compliance also influenced outcomes (adjusted HR 2.35, 95% CI: 1.32-4.18, p < 0.01). Stratified analysis showed a marked survival benefit of regular SPT among patients with periodontitis-related tooth loss (98.8% vs. 96.3%, p = 0.004). CONCLUSION:Bone-level internal connection SA implants demonstrated favorable long-term survival. However, periodontitis-related tooth loss, GBR, and SPT compliance significantly affected implant longevity, emphasizing individualized risk assessment and continuous maintenance care. The absence of longitudinal radiographic bone-level data limits further evaluation of peri-implant bone stability.

INTRODUCTION:The primary objective was to assess 1-year clinical and radiographic outcomes of a newly designed implant with a machined long neck in the anterior region, including marginal bone loss, horizontal bone width, vertical bone height, and implant survival and success rates. The secondary objective was to evaluate the effect of guided bone regeneration on bone dimensional changes and implant survival and success rates. MATERIALS AND METHODS:A total of 117 implants in 58 patients who received the novel implant in the anterior region were included. Marginal bone loss, horizontal bone width, and vertical bone height changes were assessed using panoramic radiographs and cone beam computed tomography (CBCT) scans obtained after prosthetic restoration and at the one-year follow-up. Implant survival and success rates, along with the influence of guided bone regeneration (GBR) on bone dimensional changes, were statistically analyzed. RESULTS:Within the one-year follow-up period, implant survival and success rates were 97.43% and 91.45% at the implant level, and 94.83% and 82.76% at the patient level, respectively. Among the 114 surviving implants, the mean marginal bone loss was 0.46 ± 1.05 mm. In the subset of 32 implants with available CBCT data, horizontal bone width and vertical bone height changes were minimal in both buccal and palatal/lingual aspects. Subgroup analyses indicated that guided bone regeneration provided measurable advantages in preserving bone dimensions at specific sites, particularly in the mid-buccal region and the palatal/lingual vertical height. However, at most other reference points, dimensional changes were comparable irrespective of whether GBR was performed. CONCLUSION:A novel implant featuring a machined long neck exhibited clinically acceptable outcomes with respect to implant survival, implant success, and bone dimensional stability over a one-year follow-up period.

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.

AIMS:Periodontal diseases pose significant challenges to oral health, making the regeneration of periodontal tissues a critical therapeutic goal. The goal is to restore dental function by repairing damaged tissue and reconstructing the healthy connective structure between the teeth and the alveolar bone. This study aimed to investigate the effects of selcopintide (SCPT) on the differentiation of periodontal ligament cells (PDLCs), cementoblasts, and osteoblasts in vitro, as well as the regeneration of periodontal tissue using a periodontal tissue defect model in dogs in vivo. METHODS:The expression of periodontal tissue marker genes, including periostin (POSTN), cementum attachment protein (CAP), dentin matrix protein 1 (DMP1), and bone sialoprotein (BSP), was investigated in vitro. Chronic one-wall intrabony defects were created in a total of 12 beagle dogs (n = 6 at 6 and 12 weeks, respectively), and the surgical sites were treated with no treatment, guided tissue regeneration (GTR), GTR with SCPT 50 μg/0.1 mL, 100 μg/0.1 mL, and 250 μg/0.1 mL. The effects of SCPT on the regeneration of periodontal tissues, such as periodontal ligament (PDL), cementum, and bone, were analyzed in vivo. RESULTS:SCPT influenced the proliferation and differentiation of cementoblasts and PDLCs. Real-time polymerase chain reaction analysis showed that SCPT upregulated the expression of POSTN, CAP, DMP1, and BSP compared to the control. In the periodontal defect model, SCPT regenerated the periodontal complex. Additionally, the arrangement of the newly formed PDL-like fibers was perpendicular to the newly formed cementum and alveolar bone, similar to Sharpey's fibers in natural teeth, compared with the control. CONCLUSION:In this preclinical study, histological and immunohistochemical analyses suggest that GTR with SCPT might be associated with increased periodontal ligament attachment and enhanced cementum and alveolar bone formation. Additional research with a larger sample size is needed to establish the optimal therapeutic protocols and validate the regenerative potential of SCPT.

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.

This study investigated the effect of Selcopintide (SCPT) on periodontal regeneration using surgically created class II furcation defects in an animal model, employing both radiographical and histological evaluations. Class II furcation defects were surgically induced in six beagle dogs. Each defect was unilaterally and randomly assigned to one of five treatment groups: (1) no treatment (control), (2) guided tissue regeneration (GTR) with a collagenated bone substitute and a collagen membrane, (3) GTR with an enamel matrix derivative (GTR/EMD), (4) GTR with 2 mg/ml SCPT (GTR/SCPT2), or (5) GTR with 4 mg/ml SCPT (GTR/SCPT4). Six weeks after initial surgery, identical procedures were performed on the contralateral area. Healing outcomes were assessed at 6 and 12 weeks through radiographic and histomorphometric analyses. The primary outcome was the length of the root surface covered by new cementum assessed histologically and the secondary outcome included other histomorphometric and radiographic healing outcomes. Radiographically, the GTR/SCPT groups showed significantly greater new bone volume than the control group at both 6- and 12-week timepoints (p < 0.05). Histologically, specimens treated with both formulations of SCPT displayed better-organized periodontal ligaments and improved cementum formation, similar to those treated with EMD. The group with the highest concentration of SCPT (GTR/SCPT4) exhibited the greatest amount of new cementum formation. Within the limitations of this study, both formulations of SCPT demonstrated significant regenerative potential in periodontal tissues, with outcomes comparable to those of EMD treatment, suggesting SCPT’s viability as an alternative bioactive agent for periodontal regeneration in class II furcation defects. This study suggests that SCPT could serve as a viable alternative bioactive agent for periodontal regeneration in class II furcation defect in clinical settings.

OBJECTIVE:To investigate the impact of the restorative emergence angle and splinting configurations on peri-implant soft and hard tissues. MATERIALS AND METHODS:Thirty implants were placed in the mandibular premolars (P2, P3, P4) of five beagle dogs. In a split-mouth design, each animal received both narrow (NE) (emergence angle = 30°) and wide (WE) (emergence angle = 60°) abutments on each side of the mandible. The implants were subsequently splinted. Radiographic images were captured at 0, 4, 12, and 24 weeks post-restoration. Biopsy samples were then collected for histomorphometric analysis and circularly polarized light examination. All analyses were performed based on the splinted positions: either the mesial or distal end of the terminal implant, the splinted zone of the terminal implant, or the splinted zone of the middle implant. RESULTS:Radiographic evaluation showed more pronounced bone remodeling in the WE group. In histomorphometric analysis, both the vertical distance from the implant shoulder to the alveolar bone crest and the infiltrated connective tissue areas were significantly larger in the WE group. Conversely, the NE group exhibited a longer connective tissue attachment. Analysis using circularly polarized light indicated a significantly reduced area fraction of collagen fibers in the peri-implant epithelium of the WE group, as well as in the oral epithelium of the splinted zone. CONCLUSION:A wide emergence angle of implant prostheses can compromise connective tissue attachment, hinder the formation of an adequate soft tissue seal, and potentially lead to marked bone remodeling.

Narrow-diameter implants (NDI) serve as a solution for treating limited bone volume in the anterior mandible. This study aimed to evaluate the one-year clinical outcomes of various NDIs in the mandibular incisor area after immediate loading in partially edentulous patients. This single-center, prospective, single-blinded, randomized controlled trial study included 21 patients, with 7 patients in each of the following groups: control (BLT NC SLActive®; Straumann), experimental group 1 (CMI IS-III Active® S-Narrow; Neobiotech), and experimental group 2 (CMI IS-III Active® Narrow; Neobiotech). Using full digital flow, two fixtures were placed in each patient and immediately provisionalized on the day of surgery. Evaluations encompassed periapical radiographs, implant stability quotient (ISQ), implant stability test (IST) readings, per-implant soft tissue health, patient satisfaction surveys, and esthetic score assessments. Definitive prostheses were delivered twelve weeks post-surgery (CRiS, number: KCT0007300). Following exclusions due to low stability values (n = 2), fixture failure (n = 5), and voluntary withdrawal (n = 1), the implant success rate for patients completing all clinical protocols stood at 100%. The resulting patient failure rates in the control, experimental group 1, and experimental group 2 were 50.0%, 42.9%, and 14.3%, respectively. There were no significant differences between the groups in terms of marginal bone loss, soft tissue health, patient satisfaction, and esthetic scores. Narrow implants showed superior clinical outcomes, followed by S-Narrow and Straumann implants. Calculated one-year survival rates at the implant level were 66.7% for the control group, 85.7% for experimental group 1, and 100% for experimental group 2. All three types of NDIs showed acceptable clinical and radiographic results during the year-long observation period.

Collagen membranes play a crucial role in guided bone regeneration (GBR) by preventing soft tissue infiltration and maintaining space for bone formation. This study investigated the impact of collagen membrane flexibility on GBR outcomes through in vitro and in vivo analyses. Flexible (0.3 mm in width) and stiff (0.5 mm in width) porcine collagen membranes were compared. In vitro tests assessed hydrophilicity, enzymatic degradation, conformability, space maintenance, and tensile strength. An in vivo study using a canine model evaluated bone regeneration in standardized mandibular defects filled with deproteinized porcine bone mineral and covered with no membrane, flexible membrane, or stiff membrane. Micro-computed tomography and histomorphometric analyses were performed at 8 and 16 weeks. The flexible membrane demonstrated superior hydrophilicity, faster enzymatic degradation, and greater conformability in vitro. In vivo, micro-computed tomography analysis revealed similar alveolar ridge widths across all groups. Histomorphometric analysis at 16 weeks showed significantly larger regenerated areas in the flexible membrane group compared to controls in coronal, middle, and apical regions. Both membrane groups exhibited higher regeneration ratios than controls, with significant differences in the coronal area. The flexible membrane group demonstrated significantly higher new bone formation in all regions compared to controls at 16 weeks. These findings suggest that flexible membrane substantially enhances GBR outcomes by increasing hydrophilicity and conformability. The study highlights the potential clinical benefits of incorporating flexible membranes in GBR procedures for improved bone regeneration outcomes.

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.

Non-invasive objective implant stability measurements are needed to determine the appropriate timing of prosthetic fitting after implant placement. We compared the early implant stability results obtained using resonance frequency analysis (RFA) and damping capacity analysis (DCA) depending on the implant length and bone density. Total 60, 4.0 mm diameter implants of various lengths (7.3 mm, 10 mm, and 13 mm) were used. In Group I, low-density bone was described using 15 PCF (0.24 g/cm3) polyurethane bone blocks, and in Group II, 30 PCF (0.48 g/cm3) polyurethane bone blocks were used to describe medium density bone. RFA was performed using an Osstell® Beacon+; DCA was performed using Anycheck®. Measurements were repeated five times for each implant. Statistical significance was set at P <0.05. In Group I, bone density and primary implant stability were positively correlated, while implant length and primary implant stability were positively correlated. In Group II, the implant stability quotient (ISQ) and implant stability test (IST) values in did not change significantly above a certain length. Primary implant stability was positively correlated with bone density and improved with increasing implant length at low bone densities. Compared with the Osstell® Beacon+, the simplicity of Anycheck® was easy to use and accessible.

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.

AIM:The aim of this study was to investigate the non-inferiority of alveolar ridge preservation (ARP) with membrane stabilization compared with non-stabilization, focusing on changes of soft-tissue contour in periodontally compromised extraction sockets. Secondary outcomes included changes in hard-tissue contour, patient-reported outcomes and new bone formation. MATERIALS AND METHODS:Twenty-four patients with periodontally compromised teeth were randomly assigned to ARP with (test group) or without (control group) membrane stabilization. To assess profilometric and hard-tissue dimensional changes, dental impressions and cone beam computed tomography scans were performed at baseline (T0), immediately after ARP (T1) and 4 months post surgery (T2). Soft-tissue healing in open healing sites was evaluated at T2, and wound closure was assessed 10 days post surgery. Patient-reported outcomes were documented, and core biopsies were obtained for histomorphometric analysis. RESULTS:The absolute profilometric horizontal width change at 3 mm below the crest in the test group was not inferior to that in the control group. For the relative values, horizontal width reduction (3 and 5 mm below the crest) and volumetric shrinkage (3-5 mm below the crest) were lower in the test group. No significant differences were observed in bone dimensional changes, wound healing, pain and swelling or histomorphometric outcomes. CONCLUSION:ARP with membrane stabilization in periodontally compromised extraction sockets is non-inferior in terms of soft-tissue contour changes to those without membrane fixation. TRIAL REGISTRATION:Clinical Research Information Service (CRIS), KCT0005280. Registered 4 August 2020, https://cris.nih.go.kr/cris/search/detailSearch.do?seq=19165&search_page=L.

OBJECTIVE:To compare fully guided flapless implant surgery using a light-cured surgical guide (FG group) with partially guided open flap surgery (PG group) in the posterior maxilla when performing simultaneous sinus floor elevation in terms of the accuracy, time requirements, and patient/clinician-reported outcomes (PROMs and CROMs). MATERIALS AND METHODS:In this study, 56 tissue-level implants were placed with crestal sinus floor elevation in 56 patients at single-tooth sites, with 28 implants allocated to the PG group and 28 to the FG group. The deviations of the placed implants from the virtually planned positions were measured at the implant platform and apex and for the angular deviation. The presurgical preparation time and the duration of surgery were measured. PROMs and CROMs were made by administering questionnaires at multiple time points. RESULTS:Horizontal deviations at the platform and apex and the angular deviation were significantly smaller in the FG group than the PG group (p < .05). Presurgical preparation and surgery times were significantly shorter in the FG group (p < .001). Patient satisfaction and willingness to receive repeat treatment were significantly better in the FG group than in the PG group (p < .005 and .025, respectively). Clinicians were more satisfied in the FG group than the PG group (p < .05). CONCLUSION:When placing an implant with sinus floor elevation, the flapless approach using a fully guided surgical system can be more accurate, faster, and increase the satisfaction of both the clinician and patient compared to the partially guided surgery.

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.