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Abstract Background This study aimed to demonstrate the efficacy of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser-assisted nonsurgical periodontal therapy in periodontitis patients during 8 weeks of healing. Methods A split-mouth, single-blinded, randomized controlled clinical trial was conducted on 12 patients diagnosed with stage III/IV periodontitis and had a minimum of two teeth with probing pocket depth (PPD) > 5 mm in at least two quadrants. Upon randomization, each quadrant was assigned for conventional scaling and root planing (SRP) procedure or laser-assisted therapy (SRP + laser) using radial firing tip (RFPT 5, Biolase). Clinical measurements and gingival crevicular fluid collection were performed for statistical analysis. Results In the initial statistical analysis on the whole subject teeth, modified gingival index (MGI) reduction was greater in test group at 1(P = 0.0153), 4 (P = 0.0318), and 8 weeks (P = 0.0047) compared to the control in the same period. PPD reduction at 4 weeks in test group was -1.67 ± 0.59 showing significant difference compared to the control (-1.37 ± 0.63, P = 0.0253). When teeth with mean PPD ≥5 mm were sorted, MGI decrease was significantly greater in test group at 1 (P=0.003) and 8 week (P=0.0102) follow-ups. PPD reduction was also significantly greater in test group at 4 week period (-1.98 ± 0.55 vs -1.58 ± 0.56, test vs control, P=0.0224). Conclusions Er,Cr:YSGG-assisted periodontal therapy is beneficial in MGI and PPD reductions during early healing period.

Abstract In recent years, 3D-printing technology to fabricate dental implants has garnered widespread attention due to its patient-specific customizability and cost-effectiveness. This preclinical animal study analyzed the radiographic and histomorphometric outcomes of 3D-printed implants (3DIs) placed immediately after extraction and compared them to conventional implants (CIs). 3DIs and CIs of the same dimensions placed immediately were analyzed at 2, 6, and 12 weeks. The micro-computed tomography (micro-CT) analysis revealed statistically significant differences at 2 weeks in favor of 3DIs over the CIs in terms of bone volume/tissue volume (BV/TV), bone surface/bone volume (BS/BV), trabecular bone pattern factor (Tb.Pf), and structure model index (SMI). At 2 weeks, the mean bone-to-implant contact (BIC) of the 3DIs was greater than that of the CIs; the mean bone area fraction occupancy (BAFO) and the number of Haversian canals of the 3DIs showed no statistically significant differences compared to CIs at 2 weeks. At 6 and 12 weeks, there were no statistically significant differences between the 3DIs and CIs in any parameters. Within limitations, in the early stage of extraction socket healing, the 3DIs demonstrated a higher BIC than the CIs, presenting that 3DIs may be a potential option for immediate placement to enhance osseointegration.

Abstract This study investigated early bone formation using collagenated biphasic calcium phosphate (CBCP) with or without polynucleotide (PDRN). Third (P3) or fourth (P4) premolars of six male beagle dogs were extracted and 5-mm-high dehiscence defects were created, followed by 3D-printed implant placement. The buccal bone defects were grafted with (i) CBCP and collagen membrane or (ii) CBCP soaked in polydeoxyribonucleotide (CBCP/PDRN) and collagen membrane. Samples of the experimental sites were harvested at 2- and 6-weeks post-surgery. The specimens were evaluated with radiologic and histomorphometric analysis. No significant differences were found between the CBCP and CBCP/PDRN groups in the micro-CT analysis at 2 or 6 weeks. No significant differences were observed in bone-to-implant contact (BIC) or bone area fraction occupancy (BAFO) in buccal augmented and lingual non-augmented areas. In the qualitative analysis, the new bone (NB) area and NB proportion in buccal augmented areas showed significantly higher values in the CBCP/PDRN group than in the CBCP group at 2 and 6 weeks. Peri-implant buccal dehiscence defects with immediate 3D-printed implant placement were corrected using a collagen membrane and CBCP or CBCP/PDRN. PDRN might have the potential to facilitate early bone formation with sufficient stability over time in dehiscence defects.

Abstract Recently, double-root implants have been investigated using 3D-printed technology. Here, we investigated damping capacity, microcomputed tomographic (micro-CT) and histological analyses of double-root 3D-printed implants compared with single-root 3D printed implants. Single- and double-root 3D-printed implants were fabricated and placed at both sides of mandibular third and fourth premolars in four beagle dogs. The damping capacity was measured, and periapical X-rays were taken every 2 weeks for 12 weeks. The bone volume/tissue volume (BV/TV) and bone mineral density (BMD) around the implants were measured with micro-CT. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were measured in histological samples. The implant stability values between the groups were not significantly different, except at 4 and 12 weeks. The marginal bone changes were similar at the mesial and distal areas between the groups. The BV/TV and BMD values of the double-root 3D-printed implants showed no statistical difference through micro-CT analysis, but the double-root 3D-printed implants showed lower BIC and BAFO values through histomorphometric analysis compared to the single-root 3D-printed implants. Compared to single-root implants, 3D-printed double-root implants demonstrated comparable stability and bone remodeling around the fixtures, but the statistically significant bone loss in the furcation area remains problematic.

Abstract 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.

Abstract 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.

Background: Natural (bovine-/equine-/porcine-derived) or synthetic hydroxyapatite (HA) biomaterials appear to be the preferred technologies among clinicians for bone augmentation procedures in preparation for implant dentistry. The aim of this study was to screen candidate HA biomaterials intended for alveolar ridge augmentation relative to their potential to support local bone formation/maturation and to assess biomaterial resorption using a routine critical-size rat calvaria defect model. Methods: Eighty adult male Sprague Dawley outbred rats obtained from a approved-breeder, randomized into groups of ten, were used. The calvaria defects (ø8 mm) either received sham surgery (empty control), Bio-Oss (bovine HA/reference control), or candidate biomaterials including bovine HA (Cerabone, DirectOss, 403Z013), and bovine (403Z014) or synthetic HA/ß-TCP (Reprobone, Ceraball) constructs. An 8 wk healing interval was used to capture the biomaterials’ resolution. Results: All biomaterials displayed biocompatibility. Strict HA biomaterials showed limited, if any, signs of biodegradation/resorption, with the biomaterial area fraction ranging from 22% to 42%. Synthetic HA/ß-TCP constructs showed limited evidence of biodegradation/erosion (biomaterial area fraction ≈30%). Mean linear defect closure in the sham-surgery control approximated 40%. Mean linear defect closure for the Bio-Oss reference control approximated 18% compared with 15–35% for the candidate biomaterials without significant differences between the controls and candidate biomaterials. Conclusions: None of the candidate HA biomaterials supported local bone formation/maturation beyond the native regenerative potential of this rodent model, pointing to their limitations for regenerative procedures. Biocompatibility and biomaterial dimensional stability could suggest their potential utility as long-term defect fillers.

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’ proteins and/or microbial profiles, resulting in two potential diagnosis models that achieved better diagnostic powers, with an AUC value > 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.

Background: The aim of this study was to biomechanically evaluate the initial stability of a patient-specific root analogue implant (RAI) design with drilling protocol by comparing it to designs without drilling protocol through a 3D finite element analysis (FEA). Methods: A 3D surface model of an RAI for the upper right incisor was constructed. To evaluate the effect of root apex drilling, four modified RAI shapes were designed with the press-fit implantation method: Non-modified, wedge added at root surface, lattice added at root surface, and apex-anchor added at root apex (AA). Each model was subjected to an oblique load of 100 N. To simulate the initial stability of implantation, contact conditions at the implant–bone interface were set to allow for the sliding phenomenon with low friction (frictional coefficient 0.1–0.5). Analysis was performed to evaluate micro-displacements of the implants and peak stress on the surrounding bones. Results: Under all low frictional coefficient conditions, the lowest von Mises stress level on the cortical bone and fewest micro-displacements of the implant were observed in the AA design. Conclusion: In view of these results, the AA design proved superior in reducing the stress concentration on the supporting cortical bone and the micro-displacement of RAI.

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® long implant; 5.0 × 10 mm) and experimental (CMI IS-III active® short implant; 5.5 × 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 > 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 −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.

Purpose: To analyze the biologic and mechanical complications of splinted and nonsplinted implant restorations. Materials and Methods: A total of 423 patients (n = implants: 888) were included in the study. Biologic and mechanical complications that occurred for 15 years were analyzed using the multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. Results: Biologic complications occurred in 38.7% of implants: 26.4% of nonsplinted implants (NS) and 45.4% of splinted implants (SP). Mechanical complications occurred in 49.2% of implants: 59.3% NS and 43.9% SP. Implants splinted with both mesial and distal adjacent implants (SP-mid) had the highest risk of peri-implant diseases. As the number of implants splinted increased, the risk of mechanical complications decreased. Long crown lengths increased the risk of both biologic and mechanical complications. Conclusion: Splinted implants had a higher risk of biologic complications and lower risk of mechanical complications. The implant splinted to both adjacent implants (SP-mid) had the highest risk of biologic complications. The greater the number of implants splinted, the lower the risk of mechanical complications. Long crown lengths increased the risk of both biologic and mechanical complications. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the success and survival of splinted and nonsplinted implants. Materials and Methods: A total of 423 patients (n = implants: 888) were included in the study. The success and survival of implants for 15 years were analyzed using a multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. Results: The cumulative success rate was 34.2%: 33.2% in nonsplinted (NS) and 34.8% in splinted implants (SP). The cumulative survival rate was 92.9% (94.1%, NS; 92.3%, SP). Whether to splint was not related to the success and survival of implants. The smaller the implant diameter, the lower the survival rate. The crown length and implant length were significantly associated only with NS implants: The longer the crown length and the shorter the implant length, the greater the risk of implant failure. The emergence angle (EA) and the emergence profile (EP) had a significant effect on only the SP implants: EA3 showed a higher risk than EA1, and EP2 and EP3 had a higher risk of implant failure. Conclusion: Crown length and implant length affected only the nonsplinted implants: The higher the crown length and the shorter the implant length, the greater the risk of implant failure. A significant effect for emergence contour was found only in SP implants: the implants restored with prostheses with EA ≥ 30 degrees on both the mesial and distal sides, and convex EP on at least one side had higher risks of failure. [ABSTRACT FROM AUTHOR]

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 compared with placement in a noninfected socket when sufficient healing time was provided. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 x 10 x 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. [ABSTRACT FROM AUTHOR]

Purpose: Avoiding excessive trauma—thermal or otherwise—during dental implant site preparation is considered critical to implant success; overheating is considered to be a major cause of bone necrosis. Studies evaluating thermal and mechanical effects of implant drill design are limited, and effects of flute design have not been accounted for. The purpose of this study was to compare heat generation and cutting efficiency associated with two-, three-, and four-fluted implant drills to investigate the optimal number of flutes. Materials and Methods: Two-, three-, and four-fluted dental implant drills with identical point, relief, and rake angles and otherwise standard dimensions were evaluated. Real-time temperature changes while drilling artificial bone were recorded using an infrared thermal imager. Cutting efficiency was assessed as the drilling time to a 15-mm depth under constant load using a specially designed recording system. Each drill variation was examined 20 times. A one-way analysis of variance was used for statistical analysis. Results: Mean temperature increases amounted to 8.3°C, 10.8°C, and 15.1°C for two-, three-, and four-fluted drills, respectively; temperatures significantly increased (P < .001) with an increased number of flutes. Mean drilling time serving as a measure of cutting efficiency amounted to 2.6, 2.5, and 2.5 seconds for the two-, three-, and four-fluted drills, respectively. A trend of cutting efficiency increasing or decreasing according to the number of flutes was not observed. Differences in cutting efficiency among the three drill variations were statistically significant (P = .015). The cutting efficiency of the three-fluted drill was superior to that of the two-fluted drill (P = .016). Conclusion: Within the limitations of the study, a two-fluted drill would be preferred for osteotomy preparation due to its level of heat generation, whereas a three-fluted drill showed favorable cutting efficiency. [ABSTRACT FROM AUTHOR]

Purpose: Various advanced technologies have been designed to estimate dental implant stability, including insertion torque, implant damping using the Periotest, and resonance frequency analysis expressed in implant stability quotient units. This study aimed to establish the relationship between the estimates for these three techniques. Materials and Methods: Bovine cortical bone blocks were trimmed to square shapes of precisely controlled thickness and density. Thereafter, 4-mm-diameter × 10-mm-long implants were placed in the bone blocks using 30-, 45-, and 60-Ncm insertion torques. Implant damping and resonance frequency analysis were conducted at four angles for each implant. Spearman correlation coefficients were calculated to examine the relationship between insertion torque, resonance frequency analysis, and implant damping measured values. Results: Resonance frequency analysis and implant damping estimates exhibited a strong inverse correlation (r = -0.98, P < .001). A linear equation was formulated: Periotest value = 15.54 + (-0.26 × implant stability quotient). Implant damping and resonance frequency estimates revealed a weak correlation with insertion torque (P < .05). Conclusion: This study mathematically defined a linear correlation between implant damping and resonance frequency estimates, thereby providing a guide for clinicians when deciding the loading time for dental implants using the implant damping or resonance frequency estimates. [ABSTRACT FROM AUTHOR]

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<0.001). Conclusion: The newly developed DE-CBCT technique could be used to measure jaw BMD in dentistry and may soon replace MSCT, which is expensive and requires special facilities. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: This study evaluated decontamination methods using a dental water jet and dental floss on microthreaded implants for regenerative periimplantitis therapy. Materials and Methods: In 6 beagle dogs, experimental periimplantitis was induced, and decontamination procedures, including manual saline irrigation (control group), saline irrigation using a dental water jet (group 1) and saline irrigation using a dental water jet with dental flossing (group 2), were performed. After in situ decontamination procedures, some of the implant fixtures (n = 4 per group) were retrieved for analysis by SEM, whereas other fixtures (n = 4 per group) underwent regenerative therapy. After 3 months of healing, the animals were killed. Results: The SEM examination indicated that decontamination of the implant surfaces was the most effective in group 2, with no changes in implant surface morphology. The histological examination also revealed that group 2 achieved significantly greater amounts of newly formed bone (6.75 6 2.19 mm2; P = 0.018), reosseointegration (1.88 6 1.79 mm; P = 0.038), and vertical bone fill (26.69 6 18.42%; P = 0.039). Conclusion: Decontamination using a dental water jet and dental floss on microthreaded implants showed positive mechanical debridement effects and positive bone regeneration effects. [ABSTRACT FROM AUTHOR]

Background: 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. Methods: 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. Results: 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). Conclusion: 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. [ABSTRACT FROM AUTHOR]

Background: In previous studies, oligopeptide corresponding to the cellbinding 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. Methods: 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. Results: 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. Conclusions: 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. [ABSTRACT FROM AUTHOR]

Background: The ridge-preservation technique has been applied with membrane alone or membrane plus graft. Synthetic peptides, mimicking bioactive growth factor or extracellular matrix protein, have been attempted to provide an active surface of the biomaterials in inducing bone formation while alleviating the limitations of whole protein such as short half-life, immunologic responses. The aim of the present clinical study is to examine the osteogenic effect of synthetic oligopeptide-coated bone mineral compared to bone graft without peptide when applied with collagen membrane in a ridge-preservation technique. Methods: Synthetic oligopeptide from the collagen-binding domain of osteopontin was chemically synthesized and coated onto the surface of bone mineral particulates. Ridge preservations were performed at 44 extraction sites in 42 patients (20 males and 22 females). Analyses of clinical parameters and histomorphometric evaluations were conducted to compare the osteogenic effects of the grafts between baseline and 6 months. Results: In the bone grafts of the control group treated without synthetic peptide, new bone formation was only seen around borders and basal areas. However, new bone was observed broadly in the defects of the test group treated with synthetic peptide-coated bone mineral, as seen not only at peripheries but also in the central and coronal parts of bone cores in the defects. The average percentage of new bone formation was significantly higher in the test group (5.3% ± 8.3% versus 10.4% ± 4.6%). The contact percentages between the graft particles and the new bone were 8.2% ± 11.3% for the control group and 20.4% ± 7.5% for the test group (P<0.05). Conclusions: The ridge-preservation approach using synthetic oligopeptide- coated bone mineral with collagen membrane effectively prevented the resorption of hard tissue with higher bone-to-graft contact, and the oligopeptide-coated bone may be a choice for ridge-preservation procedures while assuring new bone formation. J Periodontol 2011;82: 471-480. [ABSTRACT FROM AUTHOR]

Background: 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. Methods: 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 sealer 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. Results: The mean VAS and VRS when EMLA cream was applied (18.39 ± 14.47 mm and 0.95 ± 0.69) were significantly lower (P<0.001 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 sealer 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. Conclusion: Although most patients experienced limited pain during scaling, a significant reduction of pain is achieved by using EMLA cream and ultrasonic sealer. [ABSTRACT FROM AUTHOR]

Background: The present study was undertaken to evaluate the potential of periodontal ligament stem cells (PDLSCs) and bone marrow SCs (BMSCs) on alveolar bone regeneration in a canine peri-implant defect model. Methods: Four adult, male beagle dogs were used in this study. Au: tologous BMSCs from the lilac crests and PDLSCs from extracted teeth were cultured. Three months after extraction, BMSC- and PDLSC-loaded hydroxyapatite/13-tricalcium phosphate (HA/TCP) (test groups) and cell-free HA/TCP (control group) were implanted in three rectangular, saddle-like peri-implant defects, respectively. The left side of the mandible Was initially prepared, and after 8 weeks, the right side was also prepared. The animals were sacrificed after an 8-week healing period. Undecalcified ground sections were prepared. New bone formation and bone-to-implant contact (BIC) were measured histomorphometrically. BMSCs and PDLSCs were fluorescently labeled and traced. Results: Alveolar bone regeneration in surgically created periimplant saddle-like defects was more effective in test groups than the control group. The BMSC group had the highest new bone formation (34.99% and 40.17% at healing times of 8 and 16 weeks, respectively) followed by the PDLSC group (31.90% and 36.51%) and control group (23.13% and 28.36%), respectively. Test groups exhibited a significantly higher new bone formation than the control group at 8 weeks, but the same was true for only the BMSC group at 16 weeks (P<0.05). Fluorescently labeled cells were identified adjacent to HA/ TCP carriers and, partly, near connective tissues and osteoids. Conclusion: This study demonstrated the feasibility of using stem cell-mediated bone regeneration to treat peri-implant defects. [ABSTRACT FROM AUTHOR]