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The following consensus report is based on four background reviews (Keeve et al., Implant Dent 2019 28(2): 177–186; Ramanauskaite et al., Implant Dent 2019 28(2): 187–209; Koo et al., Implant Dent 2019 28(2): 173–176; Sculean et al., Implant Dent 2019 210–216). The surgical treatment of peri-implantitis is indicated in the cases where the first choice of treatment, the non-surgical one, failed with recurrence of bleeding and suppuration. The aim of this review was to systematically screen the literature for possible surface decontamination techniques and material during surgical treatment, the surgical regenerative and non-regenerative treatments of peri-implantitis, radiological and clinical outcomes, the importance of the presence of fixed and or keratinised peri-implant gingiva, and to determine predictable therapeutic options for the clinical surgical management of peri-implantitis lesions. Existent clinical, radiographic and microbiological data do not favour any decontamination approaches and fail to show the influence of a particular decontamination protocol on surgical therapy. Using implantoplasty in surgical non-regenerative treatment leads to a significant decrease in bleeding on probing and probing depth, and may result in improvement of clinical and radiographic parameters, up to 3 years after surgery compared with mechanical debridement alone. Surgical augmentative peri-implantitis therapy resulted in improved clinical and radiographic treatment outcomes compared with the baseline in the majority of studies with 6 months to 7–10 years of follow-up. There is no evidence to support the superiority of a specific material, product or membrane in terms of long-term clinical benefits. The best treatment modality to improve the width of keratinised attached mucosa and bleeding and plaque scores, and to sustain the peri-implant marginal bone level, is the use of an apically positioned flap combined with a free gingival graft.

Purpose To investigate the histologic differences between immediate implants placed in chronically infected sites and noninfected sites in a canine model. The histologic results of immediate implant placement also were evaluated on the basis of healing time and implant surface modification. Materials and methods Chronic endodontic-periodontic combined lesions were induced on the second, third, and fourth premolars of the hemimandible in six dogs, with the contralateral teeth as controls. Implants were immediately placed following the infected and noninfected tooth extractions using implants with a machined surface, sandblasted with alumina and acid-etched surface, and chemically modified sandblasted with alumina and acid-etched with calcium solution surface. After 1 and 3 months, three dogs were euthanized and the bone-to-implant contact, bone area fraction occupied, buccal and lingual first bone-to-implant contact from the implant platform, and buccal and lingual marginal bone loss were calculated. Results On histologic evaluation, no inflammation was observed around implants placed in the infected or noninfected sockets. At 1 month, no statistically significant differences were observed between the infected and noninfected sockets in buccal marginal bone loss in the machined implant group (P = .046), lingual first bone-to-implant contact from the implant in the sandblasted with alumina and acid-etched group (P = .046), lingual marginal bone loss in the sandblasted with alumina and acid-etched implant group (P = .028), buccal first bone-to-implant contact from the implant platform in the chemically modified sandblasted with alumina and acid-etched with calcium solution group (P = .028), and lingual first bone-to-implant contact from the implant platform in the chemically modified sandblasted with alumina and acid-etched with calcium solution group (P = .046). At 3 months, no statistically significant differences were observed in parameters between the infected and noninfected sockets for three implant surfaces. Differences between the infected and noninfected sockets were observed between the machined and sandblasted with alumina and acid-etched implant at 1 month (P = .023). Conclusion Immediate implant placement in an infected socket did not lead to any differences when compared with placement in a noninfected socket when sufficient healing time was provided.

3D printing technology has been gradually applied to various areas. In the present study, 3D-printed implants were fabricated with direct metal laser sintering technique for a dental single root with titanium. The 3D implants were allocated into following groups: not treated (3D-None), sandblasted with a large grit and acid-etched (3D-SLA), and target-ion-induced plasma-sputtered surface (3D-TIPS). Two holes were drilled in each tibia of rabbit, and the three groups of implants were randomly placed with a mallet. Rabbits were sacrificed at two, four, and twelve weeks after the surgery. Histologic and histomorphometric analyses were performed for the evaluation of mineralized bone-to-implant contact (mBIC), osteoid-to-implant contact (OIC), total bone-to-implant contact (tBIC), mineralized bone area fraction occupancy (mBAFO), osteoid area fraction occupancy (OAFO), and total bone area fraction occupancy (tBAFO) in the inner and outer areas of lattice structure. At two weeks, 3D-TIPS showed significantly higher inner and outer tBIC and inner tBAFO compared with other groups. At four weeks, 3D-TIPS showed significantly higher outer OIC than 3D-SLA, but there were no significant differences in other variables. At twelve weeks, there were no significant differences. The surface treatment with TIPS in 3D-printed implants could enhance the osseointegration process in the rabbit tibia model, meaning that earlier osseointegration could be achieved.

This study aims to investigate and assess salivary biomarkers and microbial profiles as a means of diagnosing periodontitis. A total of 121 subjects were included: 28 periodontally healthy subjects, 24 with Stage I periodontitis, 24 with Stage II, 23 with Stage III, and 22 with Stage IV. Salivary proteins (including active matrix metalloproteinase-8 (MMP-8), pro-MMP-8, total MMP-8, C-reactive protein, secretory immunoglobulin A) and planktonic bacteria (including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia, Porphyromonas nigrescens, Parvimonas micra, Campylobacter rectus, Eubacterium nodatum, Eikenella corrodens, Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, and Actinomyces viscosus) were measured from salivary samples. The performance of the diagnostic models was assessed by receiver operating characteristics (ROCs) and area under the ROC curve (AUC) analysis. The diagnostic models were constructed based on the subjects&rsquo, proteins and/or microbial profiles, resulting in two potential diagnosis models that achieved better diagnostic powers, with an AUC value &gt, 0.750 for the diagnosis of Stages II, III, and IV periodontitis (Model PA-I, AUC: 0.796, sensitivity: 0.754, specificity: 0.712) and for the diagnosis of Stages III and IV periodontitis (Model PA-II, AUC: 0.796, sensitivity: 0.756, specificity: 0.868). This study can contribute to screening for periodontitis based on salivary biomarkers.

The purpose of this study was to compare the implant survival, peri-implant marginal bone level, and peri-implant soft tissue of three different types of implants. This was performed with an early loading protocol, using a complete digital workflow, for one year of follow-up. Twenty-four patients with a single missing tooth in the mandibular posterior region were randomly assigned to the control group (SLActive Bone level implant; Institut Straumann AG, Basel, Switzerland), experiment group 1 (CMI IS-III Active implant; Neobiotech Co., Seoul, Korea), and experiment group 2 (CMI IS-III HActive implant; Neobiotech Co., Seoul, Korea). For each patient, a single implant was installed using the surgical template, and all prostheses were fabricated using a computer-aided design/computer-aided manufacturing system on a 3-dimensional model. A provisional prosthesis was implanted at 4 weeks, and a definitive monolithic zirconia prosthesis was substituted 12 weeks following the implant placement. The implant stability quotient (ISQ) and peri-implant soft tissue parameters were measured, and periapical radiographs were taken at 1, 3, 4, 8, 12, 24, 36, and 48 weeks after implant placements. Seven implants in the control group, nine implants in the experiment 1 group, and eight implants in the experiment 2 group were analyzed. There were no significant differences among the three groups in terms of insertion torque, ISQ values between surgery and 8 weeks of follow-up, marginal bone loss at 48 weeks of follow-up, and peri-implant soft tissue parameters (P > 0.05). Statistically significant differences in ISQ values were observed between the control and experiment 1 groups, and the control and experiment 2 groups at the 12 to 48 weeks’ follow-ups. Within the limits of this prospective study, an early loading protocol can be applied as a predictable treatment modality in posterior mandibular single missing restorations, achieving proper primary stability.

Background To minimize alveolar bone resorption, alveolar ridge preservation (ARP) has been proposed. Recently, interest in improving the feasibility of implant placement has gradually increased, especially in situations of infection such as periodontal and/or endodontic lesions. The aim of this study was to investigate if ARP improves feasibility of implant placement compared with no ARP in periodontally compromised sites. Secondary endpoints were the necessity of bone graft at the time of implant placement and implant failure before loading at ARP compared with no ARP. Material and methods This retrospective study was performed using dental records and radiographs obtained from patients who underwent tooth extraction due to chronic periodontal pathology. Outcomes including the feasibility of implant placement, horizontal bone augmentation, vertical bone augmentation, sinus floor elevation, total bone augmentation at the time of implant placement, and implant failure before loading were investigated. Multivariable logistic regression analysis was performed to examine the influence of multiple variables on the clinical outcomes. Results In total, 418 extraction sites (171 without ARP and 247 with ARP) in 287 patients were included in this study. The ARP group (0.8%) shows significantly lower implant placement infeasibility than the no ARP group (4.7%). Horizontal and vertical bone augmentations were significantly influenced by location and no ARP. Total bone augmentation was significantly influenced by sex, location, and no ARP. Conclusion ARP in periodontally compromised sites may improve the feasibility of implant placement. In addition, ARP attenuate the severity of the bone augmentation procedure.

OBJECTIVE To verify whether ridge preservation is effective in the reduction of dimensional loss and in bone formation compared to spontaneous healing in extraction sockets of periodontally compromised teeth. METHODS Twenty-six subjects requiring tooth extraction for stage III/IV periodontitis were randomly assigned to one of two interventions: alveolar ridge preservation using collagenated bovine bone mineral and a resorbable collagen membrane (test, RP) or spontaneous healing (control, SH). Six months later, postoperative cone-beam computed tomography (CBCT) was performed to measure the linear and volumetric changes of the sockets compared to baseline scans. Biopsies were retrieved at the implant site for histomorphometric calculations. Nonparametric tests were applied for statistical analysis. RESULTS Significantly less shrinkage occurred in RP compared to SH, mainly in the crestal zone. The width loss difference between groups was 3.3 mm and 2.2 mm at 1 mm and 3 mm below the crest, respectively (p

Previous studies demonstrated that recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered using a collagen sponge could be a candidate for periodontal regeneration therapy. However, there is little evidence related to rhBMP-2 delivered with a bilayer collagen matrix. The aim of this study was to investigate the proper dose of rhBMP-2 using a bilayer collagen matrix for periodontal regeneration in a 1-wall defect. The mandibular first premolars and first molars of 6 beagle dogs were extracted, and an 8-week healing period was allowed. One-wall intrabony defects (4 mm in width and 5 mm in height) were made on the mesial side of the 2nd premolar and/or the distal side of the 4th premolar bilaterally. Subsequently, a bilayer collagen matrix containing 0 μg (C), 200 μg (T1), or 500 μg (T2) of lyophilized rhBMP-2 was randomly applied to the defect area. Calcein and xylenol orange were injected at 4 and 8 weeks following the surgery, respectively, to label periodic bone formation. After a 12-week healing period, the animals were sacrificed for micro-computed tomography and histomorphometric analysis. Bone mineral density and bone volume density showed statistically significant differences between the control group and group T1, while no significant differences were observed between the control group and group T2 or between groups T1 and T2. The bone height in groups T1 and T2 was smaller than that in the control group. Low doses of rhBMP-2 delivered using a bilayer collagen matrix in 1-wall intrabony defects can promote periodontal regeneration compared to no or high doses of rhBMP-2.

OBJECTIVE To test whether or not topically administered recombinant human epidermal growth factor (rhEGF) accelerates the early healing phase of oral soft tissue wounds. METHODS One day following the creation of palatal defects (n = 6/animal), 14 dogs were allocated to one of the following five groups: spontaneous healing (SH), vehicle ointment (V), vehicle ointment + rhEGF at concentrations of 1 μg/g (EGF1), 10 μg/g (EGF10) or 50 μg/g (EGF50). Topical administration of ointments was repeated twice per day until sacrifice at days 8 and 16. Wound area was clinically monitored. Keratinocytes proliferation (Ki67-immunolabelling), inflammatory response (IR) and areas of collagen (C) and granulation tissue (GT) were histologically measured. Kruskal-Wallis test with Dunnett correction was used for multiple group statistical comparisons. RESULTS Clinically, in comparison with SH, a significantly smaller wound area was observed in groups EGF1 and EGF10 at day 8 (p

Background This experimental study aims to evaluate the effect of hyaluronic acid on healing of infected extraction sockets compared with recombinant human bone morphogenetic protein-2 (rhBMP-2). Methods Both third and fourth mandibular premolars of six beagle dogs were hemisected, and the distal roots were extracted at baseline. Subsequently, combined endodontic-periodontic lesions were induced at the remaining mesial roots. After 4 months, the mesial roots on both sides of the mandible were removed. Four sockets per dog were randomly allocated to four groups: Group 1, Control; Group 2, only absorbable collagen sponge (ACS: carrier); Group 3, 1% hyaluronic acid (HA) gel + ACS; and Group 4, rhBMP-2 + ACS. After 3 months of healing, the dogs were euthanized for microcomputed tomography and histologic analysis. Results After the lesion induction period (4 months), communication between the periodontal lesion and endodontic periapical lesion was observed at all remaining mesial roots. Alveolar bone overgrowth was observed in groups 3 and 4, but bone volume density was not significantly different among all groups. At the crestal portion, mineralization, and osteocalcin expression were higher in groups 3 and 4 than in groups 1 and 2. Conclusion Treatment with HA can promote bone formation and improve the wound healing rate comparable to rhBMP-2 in infected extraction sockets.

Purpose To determine whether the swelling and mechanical properties of osmotic self-inflating expanders allow or not the induction of intraoral soft tissue expansion in dogs. Methods Three different volumes (0.15, 0.25, and 0.42 mL; referred to respectively as the S , M , and L groups) of soft tissue expanders (STEs) consisting of a hydrogel core coated with a silicone-perforated membrane were investigated in vitro to assess their swelling behavior (volume swelling ratio) and mechanical properties (tensile strength, tensile strain). For in vivo investigations, the STEs were subperiosteally inserted for 4 weeks in dogs (n=5). Soft tissue expansion was clinically monitored. Histological analyses included the examination of alveolar bone underneath the expanders and thickness measurements of the surrounding fibrous capsule. Results The volume swelling ratio of all STEs did not exceed 5.2. In tensile mode, the highest mean strain was registered for the L group (98.03±0.3 g/cm), whereas the lowest mean value was obtained in the S group (81.3±0.1 g/cm), which was a statistically significant difference (P

PURPOSE This systematic review aimed to identify the effects of certain flap management procedures on ridge preservation on the basis of existing literature. MATERIALS AND METHODS Electronic (MEDLINE, EMBASE, and Cochrane Central Register of controlled trials) and manual searches of the literature were conducted until February 2017. Randomized controlled trials (RCTs), controlled clinical trials (CCTs), and prospective cohort studies that involved at least 10 subjects were eligible for this systematic review. To evaluate the beneficial effects of flap management on ridge preservation, changes in the bone width, bone height, and keratinized gingiva width were calculated using a random effects model. RESULTS Eleven studies (nine RCTs and two CCTs) were included in this review. No statistically significant differences in bone width and height changes were identified between the flapped and flapless ridge preservation techniques and between the free gingival graft and flapless ridge preservation techniques. A statistically significant shrinkage in keratinized gingiva width was noted with flapped ridge preservation compared with flapless ridge preservation (weighted mean differences, -3.21 mm; 95% confidence interval, -4.10 to -2.33; P < .00001; heterogeneity, 51%; χ2, 0.15). CONCLUSION Within the limitations, this review reveals that flapless ridge preservation was more effective in preserving bone width, bone height, and keratinized gingiva width. To present pertinent evidence regarding which flap management should be recommended for ridge preservation, more controlled and high-quality studies are warranted.

Objective: This review aimed to investigate the feasibility of immediate implant placement in infected extraction sockets. Material and methods: We performed electronic and manual searches up to March 2017 to obtain data from randomized controlled trials (RCTs) and nonrandomized controlled clinical trials (CCTs). Using a fixed-effects model to assess the difference in survival rate (primary outcome), we evaluated the risk difference for immediate implant placement in infected and non-infected sites. We estimated the weighted mean differences (WMDs) of the change in marginal bone loss (MBL), probing depth (PD), modified bleeding index (mBI), marginal gingival level (MGL) and width of keratinized gingiva (WKG) at baseline and latest follow-up. Results: In total, five studies (0 RCT, five CCTs) were included in the systematic review and three studies were included in the meta-analysis. The risk difference for immediate implant placement in an infected extraction socket compared with that in a non-infected socket was −0.02. WMDs for MBL, PD, mBI, MGL and WKG between the two groups were 0.32, 0.12, 0.07, −0.06, 0.20 and 0.51, respectively. No statistical differences were observed between the two groups, except for the change in WKG. Conclusions: Implants can be placed in infected extraction sockets after thorough socket debridement. For aesthetics, WKG should be considered when performing immediate implant placement in infected sites.

Purpose The purpose of this study was to investigate the feasibility of regenerative therapy with a collagenated bone graft and resorbable membrane in intrabony defects, and to evaluate the effects of the novel extracellular matrix (ECM)-based membrane clinically and radiologically. Methods Periodontal tissue regeneration procedure was performed using an ECM-based resorbable membrane in combination with a collagenated bovine bone graft in intrabony defects around the teeth and implants. A novel extracellular matrix membrane (NEM) and a widely-used membrane (WEM) were randomly applied to the test group and the control group, respectively. Cone-beam computed tomography images were obtained on the day of surgery and 6 months after the procedure. Alginate impressions were taken and plaster models were made 1 week and 6 months postoperatively. Results The quantity of bone tissue, the dimensional changes of the surgically treated intrabony defects, and the changes in width and height below the grafted bone substitutes showed no significant difference between the test and control groups at the 6-month examination. Conclusions The use of NEM for periodontal regeneration with a collagenated bovine bone graft showed similar clinical and radiologic results to those obtained using WEM., Graphical Abstract

Purpose The aim of this prospective pilot study was to compare alveolar ridge preservation (ARP) procedures with open-healing approach using a single-layer and a double-layer coverage with collagen membranes using radiographic and clinical analyses. Methods Eleven molars from 9 healthy patients requiring extraction of the maxillary or mandibular posterior teeth were included and allocated into 2 groups. After tooth extraction, deproteinized bovine bone mineral mixed with 10% collagen was grafted into the socket and covered either with a double-layer of resorbable non-cross-linked collagen membranes (DL group, n=6) or with a single-layer (SL group, n=5). Primary closure was not obtained. Cone-beam computed tomography images were taken immediately after the ARP procedure and after a healing period of 4 months before implant placement. Radiographic measurements were made of the width and height changes of the alveolar ridge. Results All sites healed without any complications, and dental implants were placed at all operated sites with acceptable initial stability. The measurements showed that the reductions in width at the level 1 mm apical from the alveolar crest (including the bone graft) were −1.7±0.5 mm in the SL group and −1.8±0.4 mm in the DL group, and the horizontal changes in the other areas were also similar in the DL and SL groups. The reductions in height were also comparable between groups. Conclusions Within the limitations of this study, single-layer and double-layer coverage with collagen membranes after ARP failed to show substantial differences in the preservation of horizontal or vertical dimensions or in clinical healing. Thus, both approaches seem to be suitable for open-healing ridge preservation procedures., Graphical Abstract

Purpose The aim of this study was to radiographically and clinically compare the effect of extracellular matrix (ECM) membranes on dimensional alterations following a ridge preservation procedure. Methods One of 2 different ECM membranes was applied during a ridge preservation procedure. A widely used ECM membrane (WEM; Bio-Gide, Geistlich Biomaterials, Wolhusen, Switzerland) was applied in the treatment group and a newly developed ECM membrane (NEM; Lyso-Gide, Oscotec Inc., Seongnam, Korea) was applied in the control group. Cone-beam computed tomography (CBCT) scans and alginate impressions were obtained 1 week and 6 months after the ridge preservation procedure. Results were analyzed using the independent t-test and the nonparametric Mann-Whitney U test. Results There were no significant differences between the ECM membranes in the changes in the dimension, width, and height of the extraction socket or the quantity of bone tissue. Conclusions The NEM showed comparable clinical and radiographic results to the WEM following the ridge preservation procedure., Graphical Abstract

AIM To determine the effect of alveolar ridge preservation (ARP) in molar sites without primary flap closure. MATERIALS AND METHODS Three groups were established: extraction sockets grafted with deproteinized bovine bone mineral containing 10% collagen (DBBM-C) and covered by a native bilayer collagen membrane (NBCM) (test group 1), sockets grafted with DBBM-C only (test group 2), and sockets that healed naturally (control group). Primary flap closure was not attempted. Conebeam computed tomography scans were obtained immediately and then 4 months after ARP. A biopsy was performed. The change of the marginal bone level was measured. RESULTS There was significantly less horizontal resorption in test group 1 than in the control group at levels 1 mm (-1.02 ± 0.88 [mean ± SD] vs. -4.44 ± 3.71 mm) and 3 mm (-0.31 ± 1.51 vs. -2.27 ± 1.15 mm) below the crest, and significantly less vertical reduction in the midcrestal area in test group 1 than in test group 2 (-0.25 ± 0.95 vs. -1.15 ± 1.63 mm) (p

BACKGROUND The data on the importance of soft-tissue management during surgical treatment of periimplantitis are still limited, and no clinical recommendations are yet available. AIM To give an overview on the rationale for periimplant soft-tissue augmentation procedures in the light of potential benefits/risks of the presence/absence of keratinized/attached mucosa (KAM) providing recommendations for the clinician. RESULTS The available evidence indicates that the presence of KAM favors periimplant tissue health evidenced by improved bleeding scores and facilitation of self-performed plaque removal, less mucosal recessions, and more stable marginal bone levels over time. Therefore, the rationales to augment KAM are (a) to optimize the possibility for performing an adequate level of oral hygiene, (b) to help maintaining periimplant soft-tissue health and stability, and (c) to improve esthetics. Various techniques with autogenous or xenogeneic membranes have been described so far for KAM augmentation. Additional soft-tissue grafting in conjunction with a combined regenerative and resective surgical procedure seems to be effective in treating and controlling advanced periimplantitis lesions and improving or maintaining the esthetic outcomes. CONCLUSIONS The limited available data seem to indicate that the best outcome to improve the width of KAM, and the bleeding and plaque scores, as well as to maintain the periimplant marginal bone level is the use of an apically positioned flap combined with a free gingival graft in nondiseased periimplant sites. However, at present, it is unknown: (a) to what extent soft-tissue grafting may additionally improve the outcomes after surgical (resective or regenerative) treatment of periimplantitis compared with the same approaches without soft-tissue grafting, and (b) if considered, when should soft-tissue grafting be performed (eg, before or during surgical treatment of periimplantitis). CLINICAL RECOMMENDATIONS Both soft-tissue resective and regenerative approaches may lead to successful outcomes depending on the clinical indication and defect location. However, the selection of one or another surgical approach should be based on defect type (eg, intrabony and suprabony) and location (esthetic or nonesthetic areas). The presence of an adequate width and thickness of KAM may facilitate soft-tissue (flap) management. In patients with a thin phenotype or lack of an adequate width of KAM, soft-tissue grafting may improve the clinical outcomes.

The purpose of this randomized clinical trial is to evaluate immediately loaded single implants with varying lengths in the posterior mandible using a fully digital, model-free prosthetic-driven implant planning pathway, and to compare clinical and radiological outcomes of short and long implants. The 52 patients with the single tooth missing in the posterior molar regions of the mandible were randomly assigned to the control (CMI IS-III active&reg, long implant, 5.0 &times, 10 mm) and experimental (CMI IS-III active&reg, short implant, 5.5 &times, 6.6, 7.3, 8.5 mm) groups. For each patient, a single implant was placed using the computer aided surgical template and all prostheses were fabricated by means of computer-aided design/computer-aided manufacturing (CAD/CAM) system on the virtual model. The patients received provisional and definitive monolithic zirconia prostheses at 1 week and 12 weeks after implant surgery, respectively. The implant stability quotient (ISQ) measurements and periapical radiographs were taken and peri-implant parameters were evaluated at 1, 3, 4, 8, 12, 24, 36, and 48 weeks after surgery. Nineteen long implants and 27 short implants were finally used for the statistical analysis. There was no significant difference between the groups in terms of insertion torque, ISQ values (except 3 weeks), marginal bone loss, and peri-implant soft tissue parameters (p &gt, 0.05). Both groups exhibited no stability dip during the early phase of healing. The average marginal bone loss from the baseline of implant placement for the control and experimental groups was &minus, 0.07 and 0.03 mm after 12 weeks and 0.06 and 0.05 mm after 48 weeks. All of the soft tissue parameters were within normal limits. Within the limits of the short term follow up, immediate loading of short single implants can be considered as one of predictable treatment modality in mandible with reduced bone height when primary stability can be achieved.

There have been previous studies on the relationship between periodontitis and peri-implantitis, but limited information is available on how periodontitis affects osseointegration and wound healing of newly placed dental implants adjacent to natural teeth. The objective of the present experiment is to evaluate healing around dental implants adjacent to teeth with untreated experimental periodontitis.The study included six male beagle dogs. Scaling and plaque control procedures were performed on three dogs (control group). In the other three dogs (experimental group), retraction cords and ligature wires were placed subgingivally around all premolars and the first molars. Induced experimental periodontitis was confirmed after 3 months. Each control or experimental group was divided into two subgroups depending on the timing of implant placement (immediate/delayed). Twelve dental implants (two implants for each dog) were placed immediately, and the other 12 dental implants (two implants for each dog) were placed 2 months after extraction. The animals were sacrificed 2 months after implant placement. Histologic and histometric analyses were performed.Four implants (three from the immediate placement group and one from the delayed placement group) failed in the experimental group. There were significant differences in the percentage of bone-to-implant contact and marginal bone volume density between the control and experimental groups. Both parameters were significantly lower in the experimental group than in the control group (P0.05). There was a tendency toward more marginal bone loss in the experimental group than the control group.Immediate placement of implants is associated with a higher failure rate compared with delayed placement. Untreated experimental periodontitis was correlated with compromised osseointegration in the implants with delayed placement.

Background: Pain from local anesthetic injection makes patients anxious when visiting a dental clinic. This study aims to determine differences in pain according to types of local anesthetizing methods and to identify the possible contributing factors (e.g., dental anxiety, stress, and sex). Methods: Thirty-one patients who underwent open-flap debridement in maxillary premolar and molar areas during treatment for chronic periodontitis were evaluated for this study. A randomized, split-mouth, single-masked clinical trial was implemented. The dental anxiety scale (DAS) and perceived stress scale (PSS) were administered before surgery. Two lidocaine ampules for each patient were used for local infiltration anesthesia (supraperiosteal injection). Injection pain was measured immediately after local infiltration anesthesia using the visual analog pain scale (VAS) questionnaire. Results from the questionnaire were used to assess degree of pain patients feel when a conventional local anesthetic technique (CNV) is used compared with a computer-controlled anesthetic delivery system (CNR). Results: DAS and PSS did not correlate to injection pain. VAS scores were lower for CNR than for CNV regardless of the order in which anesthetic procedures were applied. VAS score did not differ significantly with sex. Pearson coefficient for correlation between VAS scores for the two procedures was 0.80, also indicating a strong correlation. Conclusion: Within the limitations of the present study, relief from injection pain is observed using CNR. J Periodontol 2016;87:783-789.

Purpose This article describes a case of the successful non-surgical management of a periodontally compromised maxillary premolar. Methods A combination therapy, including root planing, occlusal adjustment, and tooth splinting, was applied. Clinical and radiographic examinations were performed during the 16-month follow-up period. Results All periodontal parameters were improved. There were dramatic decreases (3–6 mm) in the probing pocket depth, tooth mobility, and marginal bone loss. Interestingly, gradual resolution of the periapical radiolucency and alveolar bone regeneration were observed in the radiographs, and the periodontal condition was maintained during the follow-up period. Conclusions Within the limits of this study, these results demonstrate the importance of natural tooth preservation through proper periodontal treatment and occlusal adjustment of the periodontally compromised tooth, which is typically targeted for tooth extraction and dental implantation., Graphical Abstract

Purpose Previous studies have solely focused on fresh extraction sockets, whereas in clinical settings, alveolar sockets are commonly associated with chronic inflammation. Because the extent of tissue destruction varies depending on the origin and the severity of inflammation, infected alveolar sockets may display various configurations of their remaining soft and hard tissues following tooth extraction. The aim of this study was to classify infected alveolar sockets and to provide the appropriate treatment approaches. Methods A proposed classification of extraction sockets with chronic inflammation was developed based upon the morphology of the bone defect and soft tissue at the time of tooth extraction. The prevalence of each type of the suggested classification was determined retrospectively in a cohort of patients who underwent, between 2011 and 2015, immediate bone grafting procedures (ridge preservation/augmentation) after tooth extractions at Seoul National University Dental Hospital. Results The extraction sockets were classified into 5 types: type I, type II, type III, type IV (A & B), and type V. In this system, the severity of bone and soft tissue breakdown increases from type I to type V, while the reconstruction potential and treatment predictability decrease according to the same sequence of socket types. The retrospective screening of the included extraction sites revealed that most of the sockets assigned to ridge preservation displayed features of type IV (86.87%). Conclusions The present article classified different types of commonly observed infected sockets based on diverse levels of ridge destruction. Type IV sockets, featuring an advanced breakdown of alveolar bone, appear to be more frequent than the other socket types., Graphical Abstract

Purpose Evidence on the outcomes of functional loading placed in recombinant human bone morphogenetic protein 2 (rhBMP-2)/acellular collagen sponge (ACS)-induced bone is lacking. The aim of this study was to verify whether guided bone regeneration (GBR) with rhBMP-2/ACS enhances regeneration of missing bone and osseointegration of dental implants subject to functional loading. Materials and methods Two bilateral standardized large saddle-type defects (≈10 × 10 × 6 mm) were surgically created in each mandible of seven beagle dogs 2 months after tooth extraction. Defects were immediately reconstructed randomly using rhBMP-2 (O-BMP or InFuse) soaked in ACS, deproteinized bovine bone mineral (DBBM) granules, or ACS alone as surgical control and subsequently covered with collagen membrane. Screw-type sand-blasted, acid-etched dental implants were placed 3 months later into the reconstructed defects and into adjacent bone. Osseointegration was allowed to progress for 3 months before functional loading of 3 months until sacrifice. Results Significantly more bone fill was radiographically observed for GBR with rhBMP-2/ACS (O-BMP: 92.5%, InFuse: 79%) in comparison to the DBBM (52%) and ACS alone groups (56.6%). Osseointegration was achieved and maintained in all experimental defects challenged by prostheses-driven functional load. The bone density ranged from 37.49% in the ACS group to 64.9% in the rhBMP-2/ACS (InFuse) group with no significance. The highest mean percentage of BIC was found in rhBMP-2/ACS (InFuse: 52.98%) with no statistical difference. Crestal bone resorption was observed around implants placed in reconstructed areas without any significant difference. Conclusion GBR with rhBMP-2/ACS provided the greatest bone fill among the three treatment procedures. GBR with rhBMP-2/ACS showed efficacy for placement, osseointegration, and functional loading of titanium implants in alveolar ridge defects.

This study aimed to compare bone healing and implant stability for three types of dental implants: a threaded implant, a three-dimensional (3D)-printed implant without spikes, and a 3D-printed implant with spikes. In four beagle dogs, left and right mandibular premolars (2nd, 3rd, and 4th) and 1st molars were removed. Twelve weeks later, three types of titanium implants (threaded implant, 3D-printed implant without spikes, and 3D-printed implant with spikes) were randomly inserted into the edentulous ridges of each dog. Implant stability measurements and radiographic recordings were taken every two weeks following implant placement. Twelve weeks after implant surgery, the dogs were sacrificed and bone-to-implant contact (BIC) and bone area fraction occupied (BAFO) were compared between groups. At implant surgery, the primary stability was lower for the 3D-printed implant with spikes (74.05 &plusmn, 5.61) than for the threaded implant (83.71 &plusmn, 2.90) (p = 0.005). Afterwards, no significant difference in implants&rsquo, stability was observed between groups up to post-surgery week 12. Histomorphometrical analysis did not reveal a significant difference between the three implants for BIC (p = 0.101) or BAFO (p = 0.288). Within the limits of this study, 3D-printed implants without spikes and threaded implants showed comparable implant stability measurements, BIC, and BAFO.

This systematic review evaluates implant survival and the change in the width of the horizontal ridge following immediate implant placement with or without a regenerative procedure.An electronic search of MEDLINE, EMBASE, and the LILACS database of the Cochrane Central Register of controlled trials was performed, along with a manual search, up to April 2018. Randomized controlled trials (RCTs) and quasi-randomized controlled clinical trials (CCTs) with10 subjects were eligible for this systematic review. A meta-analysis of the risk difference in implant failure between the regenerative and non-regenerative procedure groups was performed using a fixed-effect model. In addition, a meta-analysis of the change in alveolar bone width was conducted using a fixed-effect model.Seven studies (six RCTs and one CCT) were included. A meta-analysis of three studies found no statistically significant risk difference in implant failure between the regenerative procedure and non-regenerative procedure groups. A meta-analysis of four studies showed that horizontal shrinkage of the alveolar ridge in the site of immediate implant placement was statistically significantly lower with the regenerative procedure than without it (1 year follow up studies: weighted mean difference (WMD) 0.75 mm, 95% confidence interval 0.41-1.09, p .00001; ≥1 year follow up study: WMD 1.22, 95% confidence interval 0.52-1.91, p = .00006; total: WMD 0.84 mm, 95% confidence interval 0.53-1.14, p .00001).Within the study limitations, immediate implant placement with a regenerative procedure showed similar implant survival and less shrinkage of the ridge width than immediate implant placement without a regenerative procedure. Due to the high risk of bias and small sample sizes of the included studies, further clinical studies are warranted to draw definitive conclusions.

OBJECTIVES To address the focused question: "In patients with osseointegrated implants diagnosed with periimplantitis, what are the clinical and radiographic outcomes of augmentative surgical interventions compared with nonaugmentative surgical measures"? MATERIAL AND METHODS Literature screening was performed in MEDLINE through the PubMed database, for articles published until January 1, 2018. Human studies reporting on the clinical (ie, bleeding on probing [BOP] and probing depth [PD] changes) and/or radiographic (ie, periimplant defect reduction and/or fill) treatment outcomes after surgical augmentative periimplantitis therapy, and/or comparing augmentative and nonaugmentative surgical approaches were searched. RESULTS Thirteen comparative and 11 observational clinical studies were included. Surgical augmentative periimplantitis therapy resulted in mean BOP and PD reduction ranging from 26% to 91%, and 0.74 to 5.4 mm, respectively. The reported mean radiographic fill of intrabony defects ranged between 57% and 93.3%, and defect vertical reduction varied from 0.2 to 3.77 mm. Three randomized controlled clinical studies failed to demonstrate the superiority of augmentative therapy compared with nonaugmentative approach in terms of PD and BOP reduction. CONCLUSIONS The available evidence to support superiority of augmentative surgical techniques for periimplantitis management on the treatment outcomes over nonaugmentative methods is limited.

INTRODUCTION The purpose of this review was to evaluate the available published clinical studies to understand the current data on the decontamination efficacy of various agents used in the treatment of periimplantitis and reosseointegration. MATERIALS AND METHODS An electronic PubMed literature search was conducted for studies published from 1998 until 2018. Literature on clinical studies was included in the review. Of the 189 studies retrieved from the literature search, 33 articles were selected for the review. DISCUSSION The available studies reviewed had great heterogeneity to conclude a single treatment of choice for implant surface decontamination for the surgical treatment of periimplantitis. CONCLUSIONS Existent data do not favor any decontamination approaches and fail to show the influence of a particular decontamination protocol on surgical therapy. Further clinical investigations are needed to determine the superiority of a decontamination method if existing.

Purpose This study evaluated differences in bone healing and remodeling among 3 implants with different surfaces: sandblasting and large-grit acid etching (SLA; IS-III Active®), SLA with hydroxyapatite nanocoating (IS-III Bioactive®), and SLA stored in sodium chloride solution (SLActive®). Methods The mandibular second, third, and fourth premolars of 9 dogs were extracted. After 4 weeks, 9 dogs with edentulous alveolar ridges underwent surgical placement of 3 implants bilaterally and were allowed to heal for 2, 4, or 12 weeks. Histologic and histomorphometric analyses were performed on 54 stained slides based on the following parameters: vertical marginal bone loss at the buccal and lingual aspects of the implant (b-MBL and l-MBL, respectively), mineralized bone-to-implant contact (mBIC), osteoid-to-implant contact (OIC), total bone-to-implant contact (tBIC), mineralized bone area fraction occupied (mBAFO), osteoid area fraction occupied (OAFO), and total bone area fraction occupied (tBAFO) in the threads of the region of interest. Two-way analysis of variance (3 types of implant surface×3 healing time periods) and additional analyses for simple effects were performed. Results Statistically significant differences were observed across the implant surfaces for OIC, mBIC, tBIC, OAFO, and tBAFO. Statistically significant differences were observed over time for l-MBL, mBIC, tBIC, mBAFO, and tBAFO. In addition, an interaction effect between the implant surface and the healing time period was observed for mBIC, tBIC, and mBAFO. Conclusions Our results suggest that implant surface wettability facilitates bone healing dynamics, which could be attributed to the improvement of early osseointegration. In addition, osteoblasts might become more activated with the use of HA-coated surface implants than with hydrophobic surface implants in the remodeling phase., Graphical Abstract

Purpose Periodontitis and rheumatoid arthritis (RA) share a similar inflammatory pathogenesis. Porphyromonas gingivalis (Pg) can induce anticyclic-citrullinated peptide autoantibodies (anti-CCP antibodies), a key factor in the development of RA. This study aimed at evaluating the relationships between the 2 diseases and identifying the clinical implications thereof, with a focus on periodontal pathogens in Korean adults. Methods A total of 260 RA patients and 86 age- and sex-matched control patients without arthritis were enrolled in this prospective cross-sectional study. Periodontal indices and the prevalence and amount of periodontal pathogens were compared between the groups. Correlations between periodontal and RA indices were examined, as were correlations between 9 periodontal pathogens and RA indices. Results The RA group had significantly higher values than the control group for all investigated periodontal indices (P, Graphical Abstract

A classification for peri-implant diseases and conditions was presented. Focused questions on the characteristics of peri-implant health, peri-implant mucositis, peri-implantitis, and soft- and hard-tissue deficiencies were addressed. Peri-implant health is characterized by the absence of erythema, bleeding on probing, swelling, and suppuration. It is not possible to define a range of probing depths compatible with health; Peri-implant health can exist around implants with reduced bone support. The main clinical characteristic of peri-implant mucositis is bleeding on gentle probing. Erythema, swelling, and/or suppuration may also be present. An increase in probing depth is often observed in the presence of peri-implant mucositis due to swelling or decrease in probing resistance. There is strong evidence from animal and human experimental studies that plaque is the etiological factor for peri-implant mucositis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implantitis sites exhibit clinical signs of inflammation, bleeding on probing, and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss. The evidence is equivocal regarding the effect of keratinized mucosa on the long-term health of the peri-implant tissue. It appears, however, that keratinized mucosa may have advantages regarding patient comfort and ease of plaque removal. Case definitions in day-to-day clinical practice and in epidemiological or disease-surveillance studies for peri-implant health, peri-implant mucositis, and peri-implantitis were introduced. The proposed case definitions should be viewed within the context that there is no generic implant and that there are numerous implant designs with different surface characteristics, surgical and loading protocols. It is recommended that the clinician obtain baseline radiographic and probing measurements following the completion of the implant-supported prosthesis. ispartof: JOURNAL OF CLINICAL PERIODONTOLOGY vol:45 issue:20 pages:S286-291 ispartof: location:IL, Chicago status: published

Objectives This study aimed to evaluate the safety of ridge preservation/augmentation procedures when performed at compromised extraction sockets. Methods Patients subject to ridge preservation/augmentation at periodontally compromised sockets at Seoul National University Dental Hospital(SNUDH) were evaluated in a chart review. Tooth extractions due to acute infection were not included in our study as chronically formed lesions are the only lesions that can be detected from radiographic images. If inflammatory symptoms persisted following ridge preservation/augmentation and antimicrobial and anti-inflammatory therapy, the patient was categorized as a re-infection case and implanted biomaterial removed. Results Out of 10,060 patients subject to tooth extractions at SNUDH, 2011 through 2015, 297 cases meeting inclusion criteria were reviewed. The severity and type of lesions were not specific because extracting data was only done by radiographic images and chart records. The review identified 8 patients exhibiting inflammatory symptoms that required additional antimicrobial and anti-inflammatory therapy. Within this group, re-infection occurred in 2 patients requiring biomaterials removal. The final safety rate for the ridge preservation/augmentation was 99.3%. None of the demographic factors, systemic conditions, or choice of biomaterial affected the safety of ridge preservation/augmentation. Conclusion Alveolar ridge preservation/augmentation at periodontally compromised sockets appears safe following thorough removal of infectious source. This article is protected by copyright. All rights reserved.

Purpose The aim of the present exploratory study was to evaluate extraction socket healing at sites with a history of periodontal and endodontic pathology. Methods The mandibular 4th premolar teeth in 5 adult beagle dogs served as experimental units. Periodontal and endodontic lesions were induced in 1 premolar site in each animal using wire ligatures and pulpal exposure over 3 months (diseased sites). The contralateral premolar sites served as healthy controls. The mandibular 4th premolar teeth were then extracted with minimal trauma, followed by careful wound debridement. The animals were sacrificed at days 1, 7, 30, 60, and 90 post-extraction for analysis, and the healing patterns at the healthy and diseased extraction sites were compared using radiography, scanning electron microscopy, histology, and histometry. Results During the first 7 days of healing, a significant presence of inflammatory granulation tissue was noted at the diseased sites (day 1), along with a slightly accelerated rate of fibrin clot resolution on day 7. On day 30, the diseased extraction sites showed a greater percentage of persistent fibrous connective tissue, and an absence of bone marrow formation. In contrast, healthy sites showed initial signs of bone marrow formation on day 30, and subsequently a significantly greater proportion of mature bone marrow formation on both days 60 and 90. Radiographs exhibited sclerotic changes adjoining apical endodontic lesions, with scanning electron microscopy showing collapsed Volkmann canals protruding from these regions in the diseased sites. Furthermore, periodontal ligament fibers exhibited a parallel orientation to the alveolar walls of the diseased sites, in contrast to a perpendicular arrangement in the healthy sites. Conclusions Within the limitations of this study, it appears that a history of periodontal and endodontic pathology may critically affect bone formation and maturation, leading to delayed and compromised extraction socket healing., Graphical Abstract

The purpose of this study was to compare the histologic and radiologic differences between single- and double-layer collagen membrane techniques in flapless ridge preservation. The mandibular fourth premolar and first molar of four beagle dogs were used in the experiment. Mesial roots of the teeth were extracted and root canal treatment was performed at the distal roots. Ridge preservation was performed at the extraction sites using synthetic bone graft material. A single layer (control group) or double layer (test group) of non-crosslinked collagen membrane was applied following bone graft application. Three months later, the animals were sacrificed and micro-computed tomography (micro-CT) and histomorphometric analyses were conducted. Nonparametric Mann–Whitney test was performed to compare between the control and test groups. The vertical difference between buccal and lingual crests of control and test groups was 1.28 ± 0.41 and 0.53 ± 0.37 mm, respectively (p = 0.026). The mineralized bone area in control and test groups was 31.48% ± 7.41% and 42.25% ± 9.73%, respectively (p = 0.041). Within the limit of this study, ridge preservation using the double-layer membrane technique showed a reduced buccal bone resorption and improved new-bone formation in the ridge compared to that using the single-layer membrane technique.

Purpose: Implant stability at the time of surgery is crucial for the long-term success of dental implants. Primary stability is considered of paramount importance to achieve osseointegration. The purpose of the present study was to investigate the correlation between the insertion torque and primary stability of dental implants using artificial bone blocks with different bone densities and compositions to mimic different circumstances that are encountered in routine daily clinical settings. Methods: In order to validate the objectives, various sized holes were made in bone blocks with different bone densities (#10, #20, #30, #40, and #50) using a surgical drill and insertion torque together with implant stability quotient (ISQ) values that were measured using the Osstell Mentor. The experimental groups under evaluation were subdivided into 5 subgroups according to the circumstances. Results: In group 1, the mean insertion torque and ISQ values increased as the density of the bone blocks increased. For group 2, the mean insertion torque values decreased as the final drill size expanded, but this was not the case for the ISQ values. The mean insertion torque values in group 3 increased with the thickness of the cortical bone, and the same was true for the ISQ values. For group 4, the mean insertion torque values increased as the cancellous bone density increased, but the correlation with the ISQ values was weak. Finally, in group 5, the mean insertion torque decreased as the final drill size increased, but the correlation with the ISQ value was weak. Conclusions: Within the limitations of the study, it was concluded that primary stability does not simply depend on the insertion torque, but also on the bone quality.

Background: Previous studies on ridge preservation focusing on fresh extraction sockets using graft materials for ridge preservation procedures have reported a delay in the tissue modeling and remodeling phases. The objective of this study is to evaluate the effect of hyaluronic acid (HA) on healing of infected sockets. Methods: Six beagle dogs were used in this study. Both mandibular third premolars were hemisected, and the distal roots were extracted. Subsequently, periodontal and endodontic lesions were induced at the remaining mesial root. After communication of the periodontal lesion, an endodontic periapical lesion was observed at 4 months, and the mesial roots of both the right and left sides were extracted. HA was applied into the socket of the test group, and no treatment was administered to the other group (control group). Three months after extraction of the mesial roots, the dogs were sacrificed, and histologic evaluations were performed. Results: The sockets were filled by mineralized bone (47.80% – 6.60%) and bone marrow (50.47% – 6.38%) in the control group, whereas corresponding values were 63.29% – 9.78% and 34.73% – 8.97% for the test group, respectively. There was a statistically significant difference between the groups. Reversal lines and a copious lineup of osteoblasts were observed in the middle and apical parts of the sockets in the test group. Conclusion: An infected socket shows delayed healing of the socket wound, and HA, because of its osteoinductive, bacteriostatic, and anti-inflammatory properties, may improve bone formation and accelerate wound healing in infected sockets. J Periodontol 2016;87:790-795.

To the best of our knowledge, the influence of external versus internal implant-abutment connections on crestal bone remodeling has not been reported. The aim of the present study is to investigate the influence of the abutment connection on peri-implant crestal bone levels (CBLs) using radiographic recordings.Radiographic recordings from 40 single-tooth implants (20 external and 20 internal octagonal connections; one implant/patient) in 40 patients (15 males and 25 females; mean age: 54.3 years) were selected for analyses. The radiographic evaluation included the following: 1) linear bone change (LBC); 2) dimensional change (DC); and 3) angle between the implant and adjacent bone (AIB). Differences in LBC, DC, and AIB between implant placement and 1 year after loading for each system were evaluated using a paired t test. Comparison of LBC, DC, and AIB between systems at 1 year after loading was done using analysis of covariance. The significance level was set at P ≤0.05.Radiographic CBLs (LBCs) were reduced at 1 year after loading compared to those at implant placement to reach statistical significance for the external connection (P = 0.000) but not the internal connection (P = 0.939). CBL changes were significantly greater for the external compared to the internal connection (P = 0.000). Similarly, the DC for the external connection was significantly greater compared to that for the internal connection (P = 0.004).Within the limitations of this study, the implant-abutment connection technology appears to have a significant impact on peri-implant CBLs, with the external connection paralleled by a significant reduction of CBLs.

Purpose The purpose of this study was to investigate the effects of the immunosuppressants FK506 and cyclosporin A (CsA) on the osteogenic differentiation of rat mesenchymal stem cells (MSCs). Methods The effect of FK506 and CsA on rat MSCs was assessed in vitro. The MTT assay was used to determine the deleterious effect of immunosuppressants on stem cell proliferation at 1, 3, and 7 days. Alkaline phosphatase (ALP) activity was analyzed on days 3, 7, and 14. Alizarin red S staining was done on day 21 to check mineralization nodule formation. Real-time polymerase chain reaction (RT-PCR) was also performed to detect the expressions of bone tissue-specific genes on days 1 and 7. Results Cell proliferation was promoted more in the FK506 groups than the control or CsA groups on days 3 and 7. The FK506 groups showed increased ALP activity compared to the other groups during the experimental period. The ALP activity of the CsA groups did not differ from the control group in any of the assessments. Mineralization nodule formation was most prominent in the FK506 groups at 21 days. RT-PCR results of the FK506 groups showed that several bone-related genes-osteopontin, osteonectin, and type I collagen (Col-I)-were expressed more than the control in the beginning, but the intensity of expression decreased over time. Runx2 and Dlx5 gene expression were up-regulated on day 7. The effects of 50 nM CsA on osteonectin and Col-I were similar to those of the FK506 groups, but in the 500 nM CsA group, most of the genes were less expressed compared to the control. Conclusions These results suggest that FK506 enhances the osteoblastic differentiation of rat MSCs. Therefore, FK506 might have a beneficial effect on bone regeneration when immunosuppressants are needed in xenogenic or allogenic stem cell transplantation to treat bone defects.

In previous studies, oligopeptide corresponding to the cell-binding domains of bone morphogenetic proteins that bind to bone morphogenetic protein receptor enhanced the bone regenerative capacity of bovine bone minerals (BBM). The aim of this study is to evaluate the ability of BBM coated with oligopeptide to promote periodontal regeneration in a 1-wall intrabony defect model in dogs.The second and third mandibular premolars and first molars of six adult beagles were extracted bilaterally, and the extraction sites were allowed to heal for 10 weeks. The 1-wall intrabony defects were prepared bilaterally on the mesial and distal side of the fourth mandibular premolars. Twenty-four intrabony defects were assigned to four treatment groups: 1) open flap debridement; 2) guided tissue regeneration (GTR); 3) GTR with a collagen membrane and BBM; and 4) GTR with a collagen membrane and BBM coated with the oligopeptide (Pep-BBM). The animals were sacrificed 10 weeks after surgery. For the histometric analysis, defect height, junctional epithelium migration, new cementum, new bone height, and new bone area were measured. New bone volume was measured using microcomputed tomography.Wound healing was generally uneventful. For junctional epithelium migration, the BBM and Pep-BBM groups exhibited mean (± SE) values of 0.53 ± 0.41 and 0.48 ± 0.30 mm, and for new cementum height, 1.71 ± 0.46 and 2.50 ± 2.00 mm, respectively. For junctional epithelium migration and cementum regeneration, there were no significant differences between the two groups. The mean (± SE) values of new bone height and new bone volume in the Pep-BBM group (3.88 ± 0.31 mm and 32.35% ± 9.60%) were significantly greater than the mean values for the BBM group (2.60 ± 0.41 mm and 20.56% ± 1.89%). For bone regeneration, the Pep-BBM group showed superior results compared to the BBM group with statistically significant differences.Through various parameters to evaluate periodontal regeneration, this oligopeptide coating influenced only the ability of BBM to promote bone regeneration in 1-wall intrabony defects in beagles. Junctional epithelium migration and cementum regeneration were not affected by this oligopeptide coating, and further investigations with special focus on regeneration of the periodontal ligament are necessary.

2Mediflower Clinic, Seoul, Korea Purpose: Micro-computed tomography (micro-CT) has been widely used in the evaluation of regenerated bone tissue but the reliability of micro-CT has not yet been established. This study evaluated the correlation between histomorphometric analysis and micro-CT analysis in performing new bone formation measurement. Methods: Critical-size calvarial defects were created using a 8 mm trephine bur in a total of 24 Sprague-Dawley rats, and collagen gel mixed with autogenous rat bone marrow stromal cells (BMSCs) or autogenous rat BMSCs transduced by adenovirus containing bone morphogenic protein-2 (BMP-2) genes was loaded into the defect site. In the control group, collagen gel alone was loaded into the defect. After 2 and 4 weeks, the animals were euthanized and calvaria containing defects were harvested. Micro-CT analysis and histomorphometric analysis of each sample were accomplished and the statistical evaluation about the correlation between both analyses was performed. Results: New bone formation of the BMP-2 group was greater than that of the other groups at 2 and 4 weeks in both histomorphometric analysis and micro-CT analysis (P = 0.026, P = 0.034). Histomorphometric analysis of representative sections showed similar results to histomorphometric analysis with a mean value of 3 sections. Measurement of new bone formation was highly correlated between histomorphometric analysis and micro-CT analysis, especially at the low lower threshold level at 2 weeks (adjusted r 2 = 0.907, P < 0.001). New bone formation of the BMP-2 group analyzed by micro-CT tended to decline sharply with an increasing lower threshold level, and it was statistically significant (P < 0.001). Conclusions: Both histomorphometric analysis and micro-CT analysis were valid methods for measurement of the new bone in rat calvarial defects and the ability to detect the new bone in micro-CT analysis was highly influenced by the threshold level in the BMP-2 group at early stage.

The aims of this study are to evaluate the efficacy of a eutectic mixture of local anesthetic (EMLA) cream on pain perception during scaling and to compare the intensities of pain provoked by hand and ultrasonic instruments.Forty subjects with chronic gingivitis or periodontitis were enrolled in the study. In this randomized, split-mouth, controlled, masked clinical trial, each of the four quadrants in subjects was randomly assigned to receive one of the following protocols: scaling with an ultrasonic scaler with or without the application of the EMLA cream or scaling with a Gracey curet with or without the application of the EMLA cream. Pain levels after each quadrant of scaling were assessed with a visual analog scale (VAS; 0 to 100 mm) and verbal rating score (VRS; 0 to 4). All subjects were recalled to detect any complications after 24 hours.The mean VAS and VRS when EMLA cream was applied (18.39 ± 14.47 mm and 0.95 ± 0.69) were significantly lower (P0.001 for VAS and VRS) compared to when EMLA cream was not used (26.54 ± 16.46 mm and 1.30 ± 0.75). The mean VAS and VRS of the ultrasonic scaler group (20.43 ± 16.40 mm and 0.98 ± 0.76) were significantly lower (P = 0.024 for VAS; P = 0.003 for VRS) than those of the Gracey curet group (24.50 ± 15.17 mm and 1.28 ± 0.69). None of the subjects showed adverse effects after EMLA-cream application.Although most patients experienced limited pain during scaling, a significant reduction of pain is achieved by using EMLA cream and ultrasonic scaler.

The purpose of this review is to examine various assessment methods in order to compare the accuracy between the virtually planned and clinically achieved implant positions. In this review, comparison methods using pre- and post-operative computed topography (CT) data and digital impressions for definitive prosthesis will be described. The method for the displacement and strain for quantification of the error will also be explored. The difference between the planned and the actual implant placement position in guided implant surgery is expressed as an error. Assessing the accuracy of implant-guided surgery can play an important role as positive feedback in order to reduce errors. All of the assessment methods have their own inevitable errors and require careful interpretation in evaluation.

Purpose This clinical pilot study was performed to determine the effectiveness of dual-energy cone-beam computed tomography (DE-CBCT) in measuring bone mineral density (BMD). Materials and Methods The BMD values obtained using DE-CBCT were compared to those obtained using calibrated multislice computed tomography (MSCT). After BMD calibration with specially designed phantoms, both DE-CBCT and MSCT scanning were performed in 15 adult dental patients. Three-dimensional (3D) Digital Imaging and Communications in Medicine data were imported into a dental software program, and the defined regions of interest (ROIs) on the 3-dimensional surface-rendered images were identified. The automatically-measured BMD values of the ROIs (g/cm3), the differences in the measured BMD values of the matched ROIs obtained by DE-CBCT and MSCT 3D images, and the correlation between the BMD values obtained by the 2 devices were statistically analyzed. Results The mean BMD values of the ROIs for the 15 patients as assessed using DE-CBCT and MSCT were 1.09±0.07 g/cm3 and 1.13±0.08 g/cm3, respectively. The mean of the differences between the BMD values of the matched ROIs as assessed using DE-CBCT and calibrated MSCT images was 0.04±0.02 g/cm3. The Pearson correlation coefficient between the BMD values of DE-CBCT and MSCT images was 0.982 (r=0.982, P

Purpose This study aimed to evaluate the effect of two different implant-abutment connection structures with identical implant design on peri-implant bone level. Materials and methods This clinical study was a patient-blind randomized controlled trial following the CONSORT 2010 checklists. This trial was conducted in 24 patients recruited between March 2013 and July 2015. Implants with internal friction connection were compared to those with external hex connection. One implant for each patient was installed, replacing the second molar. Implant-supported crowns were delivered at four months after implant insertion. Standardized periapical radiographs were taken at prosthesis delivery (baseline), and one year after delivery. On the radiographs, distance from implant shoulder to first bone-to-implant contact (DIB) and peri-implant area were measured, which were the primary and secondary outcome, respectively. Results Eleven external and eleven internal implants were analyzed. Mean changes of DIB from baseline to 1-year postloading were 0.59 (0.95) mm for the external and 0.01 (0.68) mm for the internal connection. Although no significant differences were found between the two groups, medium effect size was found in DIB between the connections (Cohen's d = 0.67). Conclusion Considering the effect size in DIB, this study suggested the possibility of the internal friction connection structure for more effective preservation of marginal bone.

Our special thanks to Osstem Implant Inc., Busan, Korea for manufacturing the postulated drills that were used in this study.

To our knowledge, no study has evaluated the success or survival rate of single-tooth implants that replaced missing maxillary and mandibular second molars. The purpose of the present study was to evaluate the 1- to 5-year cumulative survival rate (CSR) for single-tooth implants placed in the second molar region and the effects of associated factors.Four hundred eighty-nine patients (298 males and 191 females; age range: 23 to 91 years; mean age: 47 years) who were admitted to the Seoul National University Dental Hospital between March 2003 and July 2008 and treated with single-tooth implants in the second molar region (227 maxillary implants and 294 mandibular implants; total: 521 implants) were included in the study. Thirty-two subjects received two implants each. A 1- to 5-year CSR was calculated using a life-table analysis. A comparison of CSRs between maxillary versus mandibular implants, one-stage versus two-stage implants, short (or=8.5 mm) versus long (10 mm) implants, and standard-diameter (or=4.0 mm) versus wide-diameter (or=5.0 mm) implants was performed using Wilcoxon (Gehan) statistics. P0.05 was considered significant.Fifteen of the 521 implants were lost between insertion and the follow-up examinations. The 1- to 5-year CSR was 95.1%. There were no statistically significant differences in CSRs between implants placed in maxillas and mandibles (96.3% versus 94.9%, respectively; P = 0.084), one- and two-stage implants (95.6% versus 94.7%, respectively; P = 0.267), short and long implants (100% versus 95.1%, respectively; P = 0.582), and standard- and wide-diameter implants (93.8% versus 96.8%, respectively; P = 0.065).Within the limitations of the study, the placement of single-tooth implants in the second molar region was an effective and reliable treatment modality. Also, associated factors such as implant diameter, length, and location (the maxilla versus the mandible) may not have an impact on the long-term success of implants.

Purpose: The purpose of this study was to compare the bone regeneration effects of cortical, cancellous, and cortico-cancel lous human bone substitutes on calvarial defects of rabbits. Methods: Four 8-mm diameter calvarial defects were created in each of nine New Zealand white rabbits. Freeze-dried cortical bone, freeze-dried cortico-cancellous bone, and demineralized bone matrix with freeze-dried cancellous bone were inserted into the defects, while the non-grafted defect was regarded as the control. After 4, 8, and 12 weeks of healing, the experimental animals were euthanized for specimen preparation. Micro-computed tomography (micro-CT) was performed to calculate the percent bone volume. After histological evaluation, histomorphometric analysis was performed to quantify new bone formation. Results: In micro-CT evaluation, freeze-dried cortico-cancellous human bone showed the highest percent bone volume value among the experimental groups at week 4. At week 8 and week 12, freeze-dried cortical human bone showed the highest percent bone volume value among the experimental groups. In histologic evaluation, at week 4, freeze-dried cortico-cancellous human bone showed more prominent osteoid tissue than any other group. New bone formation was increased in all of the experimental groups at week 8 and 12. Histomorphometric data showed that freeze-dried cortico-cancellous human bone showed a significantly higher new bone formation percentile value than any other experimental group at week 4. At week 8, freeze-dried cortical human bone showed the highest value, of which a significant difference existed between freeze-dried cortical human bone and demineralized bone matrix with freeze-dried cancellous human bone. At week 12, there were no significant differences among the experimental groups. Conclusions: Freeze-dried cortico-cancellous human bone showed swift new bone formation at the 4-week healing phase, whereas there was less difference in new bone formation among the experimental groups in the following healing phases.

Purpose: It has been reported that low-level semiconductor diode lasers could enhance the wound healing process. The periodontal ligament is crucial for maintaining the tooth and surrounding tissues in periodontal wound healing. While low-level semiconductor diode lasers have been used in low-level laser therapy, there have been few reports on their effects on periodon tal ligament fibroblasts (PDLFs). We performed this study to investigate the biological effects of semiconductor diode lasers on human PDLFs. Methods: Human PDLFs were cultured and irradiated with a gallium-aluminum-arsenate (GaAlAs) semiconductor diode laser of which the wavelength was 810 nm. The power output was fixed at 500 mW in the continuous wave mode with various energy fluencies, which were 1.97, 3.94, and 5.91 J/cm 2 . A culture of PDLFs without laser irradiation was regarded as a control. Then, cells were additionally incubated in 72 hours for MTS assay and an alkaline phosphatase (ALPase) activity test. At 48 hours post-laser irradiation, western blot analysis was performed to determine extracellular signal-regulated kinase (ERK) activity. ANOVA was used to assess the significance level of the differences among groups (P

In a previous study, recombinant human transforming growth factor-beta1 (rhTGF-beta(1)) in a calcium carbonate carrier was implanted into critical-size, supraalveolar periodontal defects under conditions for guided tissue regeneration (GTR) to study whether rhTGF-beta(1) would enhance or accelerate periodontal regeneration. The results showed minimal benefits of rhTGF-beta(1), and a clear account for this could not be offered. One potential cause may be that the rhTGF-beta(1) formulation was biologically inactive. Several growth or differentiation factors have been suggested to accelerate degradation of biomaterials used as carriers. The objective of this study was to evaluate possible activity of rhTGF-beta(1) on biodegradation of the calcium carbonate carrier.rhTGF-beta(1) in a putty-formulated particulate calcium carbonate carrier was implanted into critical-size, supraalveolar periodontal defects under conditions for GTR in five beagle dogs. Contralateral defects received the calcium carbonate carrier combined with GTR without rhTGF-beta(1) (control). The animals were euthanized at week 4 post-surgery and block biopsies of the defect sites were collected for histologic and histometric analysis. Radiographs were obtained at defect creation and weeks 2 and 4 after defect creation.No statistically significant differences were observed in new bone formation (bone height and area) among the treatments. However, total residual carrier was significantly reduced in sites receiving rhTGF-beta(1) compared to control (P = 0.04). Similarly, carrier density was considerably reduced in sites receiving rhTGF-beta(1) compared to control; the difference was borderline statistically significant (P = 0.06).Within the limitations of the study, it may be concluded that rhTGF-beta(1) accelerates biodegradation of a particulate calcium carbonate biomaterial, indicating a biologic activity of the rhTGF-beta(1) formulation apparently not encompassing enhanced or accelerated periodontal regeneration.