Purpose: This study retrospectively investigated the long-term clinical and radiographic outcomes of a bone-level type, 2-piece, internal connection dental implant system characterized by coronal microthreads. Methods: A total of 872 implants placed in 284 patients were selected from 1,845 implants placed in 691 patients by experienced periodontists at Yonsei University Dental Hospital.These selected implants had been followed up for over 10 years and were included in the present study. A statistical evaluation of implant survival and treatment success, based on changes in marginal bone levels, was conducted using electronic records and consecutively taken radiographs. Results: Over a follow-up period of 12.3±2.0 years, 830 of the 872 implants remained intact, yielding a cumulative survival rate of 95.2% at the implant level and 88.4% at the patient level.The cumulative treatment success rates, characterized by marginal bone loss of less than 2 mm, stood at 87.0% for implants and 76.1% for patients. Among the 830 surviving implants, 113 fixtures were classified as ailing, with an average marginal bone loss of 4.09±1.44 mm.Cox regression analysis revealed that implants 8 mm in length or shorter were significantly more likely to fail or experience pathologic marginal bone resorption, with hazard ratios of 3.71 and 2.00, respectively (P<0.05). Conclusions The survival and treatment success of the investigated microthreaded, bone-level, 2-piece, internal connection implants were acceptable over a follow-up period exceeding 10 years. However, shorter dental implants exhibited a higher propensity for failure and excessive marginal bone loss.

Purpose: This study was performed to evaluate the effects of flap design, grafting material, and graft dimension on flap tension and the initial volume increase achieved in soft tissue augmentation. Methods: Six fresh porcine jaw cadavers were used in this study. Each side of the jaw was randomly assigned to receive either a standard split-thickness flap or a split-thickness flap with a palatal island. Following flap preparation, random allocation was employed to determine the order of 4 treatment modalities: 3 mm of a volume-stable collagen matrix (VCMX), 6 mm VCMX, 3 mm of a subepithelial connective tissue graft (SCTG), and 6 mm SCTG. Flap tension was measured and the wound was closed after the insertion of each specimen. Intraoral scans were taken before flap preparation and after closure to facilitate profilometric analysis. Results: The palatal island flap exhibited significantly greater overall (P=0.010) and crestal (P=0.007) volume gains compared to the split-thickness flap, regardless of the use of VCMX or SCTG. The palatal island flap was associated with significantly lower flap tension force values (0.6 N; P=0.035) than the split-thickness flap. Both materials (VCMX and SCTG) demonstrated comparable volume gains. Conclusions The findings of this cadaveric study indicate that the use of a palatal island flap effectively reduces flap tension. While both materials (VCMX and SCTG) yielded similar increases in volume, the palatal island flap demonstrated greater volume gains than the splitthickness flap for each grafting material.

Purpose: The aim of this study was to compare changes in soft and hard tissue and the histologic composition following early implant placement in sites with alveolar ridge preservation or spontaneous healing (SH), as well as implant performance up to 1 year after crown insertion. Methods: Thirty-five patients with either intact buccal bone plates or dehiscence of up to 50% following single-tooth extraction of incisors, canines, or premolars were included in the study. They were randomly assigned to undergo one of three procedures: deproteinized bovine bone mineral with 10% collagen (DBBM-C) covered by a collagen matrix (DBBM-C/ CM), DBBM-C alone, or SH. At 8 weeks, implant placement was carried out, and cone-beam computed tomography scans and impressions were obtained for profilometric analysis.Patients were followed up after the final crown insertion and again at 1 year post-procedure. Results: Within the first 8 weeks following tooth extraction, the median height of the buccal soft tissue contour changed by −2.11 mm for the DBBM-C/CM group, −1.62 mm for the DBBM-C group, and −1.93 mm for the SH group. The corresponding height of the buccal mineralized tissue changed by −0.27 mm for the DBBM-C/CM group, −2.73 mm for the DBBM-C group, and −1.48 mm for the SH group. The median contour changes between crown insertion and 1 year were −0.19 mm in the DBBM-C/CM group, −0.09 mm in the DBBM-C group, and −0.29 mm in the SH group. Conclusions Major vertical and horizontal ridge contour changes occurred, irrespective of the treatment modality, up to 8 weeks following tooth extraction. The DBBM-C/CM preserved more mineralized tissue throughout this period, despite a substantial reduction in the overall contour. All 3 protocols led to stable tissues for up to 1 year.

Purpose: This study systematically evaluated the implications of advanced age on postsurgical outcomes following gastrectomy for gastric cancer using a national database. Materials and Methods: The 2011–2017 National Inpatient Sample was used to isolate patients who underwent gastrectomy for gastric cancer. From this, the population was stratified into those belonging to the younger age cohort (18–59 years), sexagenarians, septuagenarians, and octogenarians. The younger cohort and each advanced age category were compared in terms of the following endpoints: mortality following surgery, length of hospital stay, charges, and surgical complications. Results: This study included a total of 5,213 patients: 1,366 sexagenarians, 1,490 septuagenarians, 743 octogenarians, and 1,614 under 60 years of age. Between the younger cohort and sexagenarians, there was no difference in mortality (2.27 vs. 1.67%; P=0.30; odds ratio [OR], 1.36; 95% confidence interval [CI], 0.81–2.30), length of stay (11.0 vs. 11.1 days; P=0.86), or charges ($123,557 vs. $124,425; P=0.79). Compared to the younger cohort, septuagenarians had higher rates of in-hospital mortality (4.30% vs. 1.67%; P<0.01; OR, 2.64; 95% CI, 1.67–4.16), length of stay (12.1 vs. 11.1 days; P<0.01), and charges ($139,200 vs. $124,425; P<0.01). In the multivariate analysis, septuagenarians had higher mortality (P=0.01; adjusted odds ratio [aOR], 2.01; 95% CI, 1.18–3.43). Similarly, compared to the younger cohort, octogenarians had a higher rate of mortality (7.67% vs. 1.67%; P<0.001; OR, 4.88; 95% CI, 3.06–7.79), length of stay (12.3 vs. 11.1 days; P<0.01), and charges ($131,330 vs. $124,425; P<0.01). In the multivariate analysis, octogenarians had higher mortality (P<0.001; aOR, 4.03; 95% CI, 2.28–7.11). Conclusions Advanced age (>70 years) is an independent risk factor for postoperative death in patients with gastric cancer undergoing gastrectomy.

Purpose: To compare the long-term changes in surgically induced astigmatism (SIA) in patients who underwent 23-gauge sutureless vitrectomy and cataract surgery together with patients who underwent cataract surgery only. Methods: We retrospectively reviewed SIA changes for 1 year after surgery in patients who received only cataract surgery using phacoemulsification (group 1) and patients who underwent 23-gauge sutureless vitrectomy and cataract surgery together (group 2). Flat keratometry (K1), steep keratometry (K2), and astigmatism axis were measured with automatic keratometry before and after the surgery. Vector analysis was used to calculate SIA at 1, 3, 6, and 12 months postoperatively. We then examined whether the SIA values at each time point were different between the two groups. Results: A total of 86 eyes were included in this study (group 1, n = 45; group 2, n = 41). The mean SIA values calculated at 1, 3, 6, and 12 months after surgery in group 1 were 0.83 ± 0.37, 0.69 ± 0.39, 0.60 ± 0.33, and 0.59 ± 0.33, respectively. In group 2, the values were 0.82 ± 0.47, 0.69 ± 0.38, 0.62 ± 0.28, and 0.61 ± 0.30, respectively. Over time, SIA decreased in both groups (all p < 0.001). There was no significant difference in the mean SIA between the two groups at each follow-up time point after surgery (p = 0.296, p = 0.728, p = 0.361, and p = 0.356, respectively). Conclusions When 23-gauge sutureless vitrectomy and cataract surgery were performed together, the astigmatism change caused by surgery did not show a significant difference compared with that of the group who received cataract surgery only. Thus, 23-gauge sutureless vitrectomy may not significantly affect corneal astigmatism.

Purpose: To compare the long-term changes in surgically induced astigmatism (SIA) in patients who underwent 23-gauge sutureless vitrectomy and cataract surgery together with patients who underwent cataract surgery only. Methods: We retrospectively reviewed SIA changes for 1 year after surgery in patients who received only cataract surgery using phacoemulsification (group 1) and patients who underwent 23-gauge sutureless vitrectomy and cataract surgery together (group 2). Flat keratometry (K1), steep keratometry (K2), and astigmatism axis were measured with automatic keratometry before and after the surgery. Vector analysis was used to calculate SIA at 1, 3, 6, and 12 months postoperatively. We then examined whether the SIA values at each time point were different between the two groups. Results: A total of 86 eyes were included in this study (group 1, n = 45; group 2, n = 41). The mean SIA values calculated at 1, 3, 6, and 12 months after surgery in group 1 were 0.83 ± 0.37, 0.69 ± 0.39, 0.60 ± 0.33, and 0.59 ± 0.33, respectively. In group 2, the values were 0.82 ± 0.47, 0.69 ± 0.38, 0.62 ± 0.28, and 0.61 ± 0.30, respectively. Over time, SIA decreased in both groups (all p < 0.001). There was no significant difference in the mean SIA between the two groups at each follow-up time point after surgery (p = 0.296, p = 0.728, p = 0.361, and p = 0.356, respectively). Conclusions When 23-gauge sutureless vitrectomy and cataract surgery were performed together, the astigmatism change caused by surgery did not show a significant difference compared with that of the group who received cataract surgery only. Thus, 23-gauge sutureless vitrectomy may not significantly affect corneal astigmatism.

Objective: The genetic background of mood disorders is gradually emerging through the use of large multicenter samples but a detailed phenotyping is complementary in elucidating the role of modulating variants. Methods: In the present paper we focused on the possible modulatory effects of ARC gene variants on two independent mood disorder samples of European (n = 246 bipolar disorder) and Korean (n = 132 bipolar disorder; n = 242 major depressive disorder [MDD]) ancestry. Results: No result survived Bonferroni correction, however we evidenced promising trend toward possible association between ARC gene variants and mood disorder phenotypes. In particular, we evidenced weak correlations of ARC single nucleotide polymorphisms with depressive symptoms severity (evaluated through Hamilton depression rating scale scores) in the MDD Korean (rs7465272) and European (rs11167152) samples. Additionally rs10110456 was found to be related to Family History, while rs7465272 was related to suicide risk in the Korean sample. Finally, rs7465272 was associated with body mass index in the European sample. Conclusion Overall, ARC gene variants may have a partial role in modulatory effect on treatment efficacy or phenotypes of mood disorders. Further studies, on larger samples may provide a better understanding on the role of ARC gene variants in the symptom severity and treatment outcomes in patients with mood disorders.

Purpose: The purpose of this study was to examine the local tissue reactions associated with 3 different poly(lactic-co-glycolic acid) (PLGA) prototype membranes and to compare them to the reactions associated with commercially available resorbable membranes in rats. Methods: Seven different membranes—3 synthetic PLGA prototypes (T1, T2, and T3) and 4 commercially available membranes (a PLGA membrane, a poly[lactic acid] membrane, a native collagen membrane, and a cross-linked collagen membrane)—were randomly inserted into 6 unconnected subcutaneous pouches in the backs of 42 rats. The animals were sacrificed at 4, 13, and 26 weeks. Descriptive histologic and histomorphometric assessments were performed to evaluate membrane degradation, visibility, tissue integration, tissue ingrowth, neovascularization, encapsulation, and inflammation. Means and standard deviations were calculated. Results: The histological analysis revealed complete integration and tissue ingrowth of PLGA prototype T1 at 26 weeks. In contrast, the T2 and T3 prototypes displayed slight to moderate integration and tissue ingrowth regardless of time point. The degradation patterns of the 3 synthetic prototypes were similar at 4 and 13 weeks, but differed at 26 weeks. T1 showed marked degradation at 26 weeks, whereas T2 and T3 displayed moderate degradation.Inflammatory cells were present in all 3 prototype membranes at all time points, and these membranes did not meaningfully differ from commercially available membranes with regard to the extent of inflammatory cell infiltration. Conclusions The 3 PLGA prototypes, particularly T1, induced favorable tissue integration, exhibited a similar degradation rate to native collagen membranes, and elicited a similar inflammatory response to commercially available non–cross-linked resorbable membranes.The intensity of inflammation associated with degradable dental membranes appears to relate to their degradation kinetics, irrespective of their material composition.

PURPOSE: To evaluate the effects of intra-alveolar socket grafting, subepithelial connective tissue grafts, and individualized abutments on peri-implant hard and soft tissue outcomes following immediate implant placement. METHODS: This randomized experimental study employed 5 mongrel dogs, with 4 sites per dog (total of 20 sites). The mesial roots of P3 and P4 were extracted in each hemimandible and immediate dental implants were placed. Each site was randomly assigned to 1 of 4 different treatment groups: standardized healing abutment (control group), alloplastic bone substitute material (BSS) + standardized healing abutment (SA group), BSS + individualized healing abutment (IA group), and BSS + individualized healing abutment + a subepithelial connective tissue graft (IAG group). Clinical, histological, and profilometric analyses were performed. The intergroup differences were calculated using the Bonferroni test, setting statistical significance at P<0.05. RESULTS: Clinically, the control and SA groups demonstrated a coronal shift in the buccal height of the mucosa (0.88±0.48 mm and 0.37±1.1 mm, respectively). The IA and IAG groups exhibited an apical shift of the mucosa (−0.7±1.15 mm and −1.1±0.96 mm, respectively). Histologically, the SA and control groups demonstrated marginal mucosa heights of 4.1±0.28 mm and 4.0±0.53 mm relative to the implant shoulder, respectively. The IA and IAG groups, in contrast, only showed a height of 2.6 mm. In addition, the height of the mucosa in relation to the most coronal buccal bone crest or bone substitute particles was not significantly different among the groups. Volumetrically, the IA group (−0.73±0.46 mm) lost less volume on the buccal side than the control (−0.93±0.44 mm), SA (−0.97±0.73 mm), and IAG (−0.88±0.45 mm) groups. CONCLUSIONS: The control group demonstrated the most favorable change of height of the margo mucosae and the largest dimensions of the peri-implant soft tissues. However, the addition of a bone substitute material and an individualized healing abutment resulted in slightly better preservation of the peri-implant soft tissue contour.
Animals ; Bone Substitutes ; Connective Tissue ; Dental Implants ; Dogs ; Mucous Membrane ; Shoulder ; Tissue Transplantation ; Transplants

PURPOSE: The purpose of the present study was to validate an experimental model for assessing tissue integration of titanium and zirconia implants with and without buccal dehiscence defects. METHODS: In 3 dogs, 5 implants were randomly placed on both sides of the mandibles: 1) Z1: a zirconia implant (modified surface) within the bony housing, 2) Z2: a zirconia implant (standard surface) within the bony housing, 3) T: a titanium implant within the bony housing, 4) Z1_D: a Z1 implant placed with a buccal bone dehiscence defect (3 mm), and 5) T_D: a titanium implant placed with a buccal bone dehiscence defect (3 mm). The healing times were 2 weeks (one side of the mandible) and 6 weeks (the opposite side). RESULTS: The dimensions of the peri-implant soft tissue varied depending on the implant and the healing time. The level of the mucosal margin was located more apically at 6 weeks than at 2 weeks in all groups, except group T. The presence of a buccal dehiscence defect did not result in a decrease in the overall soft tissue dimensions between 2 and 6 weeks (4.80±1.31 and 4.3 mm in group Z1_D, and 4.47±1.06 and 4.5±1.37 mm in group T_D, respectively). The bone-to-implant contact (BIC) values were highest in group Z1 at both time points (34.15%±21.23% at 2 weeks, 84.08%±1.33% at 6 weeks). The buccal dehiscence defects in groups Z1_D and T_D showed no further bone loss at 6 weeks compared to 2 weeks. CONCLUSIONS: The modified surface of Z1 demonstrated higher BIC values than the surface of Z2. There were minimal differences in the mucosal margin between 2 and 6 weeks in the presence of a dehiscence defect. The present model can serve as a useful tool for studying peri-implant dehiscence defects at the hard and soft tissue levels.
Animals ; Dental Implants ; Dogs ; Housing ; Mandible ; Models, Theoretical ; Mouth Mucosa ; Osseointegration ; Surface Properties ; Titanium