A retrospective radiographic study was conducted from five private dental offices on patients requesting dental implant therapy to replace their missing teeth. All implants were placed and restored by early 2000, and patients were encouraged to continue their dental care at the same office. The records were reviewed and analyzed by the clinicians, who had more than 15 years of dental experience at the time of the initial patient treatment. A total of 74 patients with 242 implants were recalled up to 10 years (mean follow-up: 9.21 ± 1.7 years) after loading. There were five implant failures from this radiographic observation period, resulting in a 97.9% dental implant survival rate. The mean crestal bone level change on the mesial aspect was -0.36 ± 1.05 mm, while the mean crestal bone level change on the distal aspect was -0.18 ± 0.96 mm. Thus, the overall mean bone loss was -0.28 ± 0.05 mm. The dental implants, which had a sandblasted, large-grit, acid-etched surface, appeared to achieve successful osseointegration in this long-term observation period, and the implant system's unique design and surface features resulted in a stable osseous crest without bone loss to the first thread.

Purpose: The aim of this retrospective study was to evaluate cumulative survival rate (CSR) of Implantium implants followed for 5 years and association between risk factors and the CSR.

Materials and Methods: A total of two hundred forty-nine Implantium Implants System (Dentium, Seoul, Korea) placed in ninety-five patients from 2004 to 2009 were investigated with several identified risk factors (sex, systemic disease, smoking, alchohol, reason of tooth loss, length, arch (maxilla or mandible), replace tooth type (incisor, canine, premolar or molar) Kennedy classification, prosthodontic type, prosthodontic design, opposite dentition, abutment type, occlusal material, occlusal unit, splint to tooth, cantilever, other surgery). Clinical examination (mobility, percussion, screw loosening, discomfort, etc.) and radiographic examination data were collected from patient records including all problems during follow-up period according to protocols described earlier. Life table analysis was undertaken to examine the CSR. Cox regression method was conducted to assess the association between potential risk factors and overall CSR.

Results: Five of 249 implants were failed. Four of these were lost before loading. The 5-year implant cumulative survival rate was 97.37%. Cox regression analysis demonstrated a significant predictive association between overall CSR and systemic disease, smoking, reason of tooth loss, arch, Kennedy classification and prosthodontic design (P<.05). The screw related complication was rare. Two abutment screw fractures were found. Another complications of prosthetic components were porcelain fracture, resin facing fracture and denture fracture (n=19).

Conclusion: The 5-year CSR of Implantium implants was 97.37%. Implant survival may be dependent upon systemic disease, smoking reason of tooth loss, arch, Kennedy classification and prosthodontic design (P<.05). The presence of systemic diseases and combination of other surgical procedures may be associated with increased implant failure.

Statement of problem: Unlike conventional loading protocols, the immediate loading of single implants has not been fully investigated.

Purpose: The purpose of this study was to assess the prosthetic and esthetic periimplant mucosal outcomes of immediately restored dental implants during a 1-year follow-up.

Material and methods: Twenty participants meeting the established inclusion criteria received double-threaded, tapered body dental implants (SuperLine; Dentium). Implants were placed and stabilized at a minimum of 35 Ncm of torque and restored immediately after the surgery with interim restorations. These were replaced with definitive restorations 6 months after implant placement. Clinical measurements at each visit included resonance frequency analysis, the evaluation of the participants' oral health (gingival and plaque indices), and the esthetic outcome of the interim or definitive restoration.

Results: Implants placed in this clinical study had a 100% success rate. The oral health and esthetic outcomes were favorable for all participants.

Conclusions: Double-threaded, tapered body dental implants that were placed and immediately restored with fixed interim prostheses and with definitive prostheses after 6 months remained stable and functional after 1 year.

Many patients and clinicians would prefer a synthetic particulate bone replacement graft, but most available alloplastic biomaterials have limited osteogenic potential. An alloplast with increased regenerative capacity would be advantageous for the treatment of localized alveolar ridge defects. This prospective, randomized controlled preclinical trial utilized 6 female foxhounds to analyze the osteogenic impact of different formulations of biphasic calcium phosphate (BCP) in combination with an hydroxyapatite-collagen membrane and their ability to reconstruct deficient alveolar ridges for future implant placement. The grafted sites were allowed to heal 3 months, and then trephine biopsies were obtained to perform light microscopic and histomorphometric analyses. All treated sites healed well with no early membrane exposure or adverse soft tissue responses during the healing period. The grafted sites exhibited greater radiopacity than the surrounding native bone with BCP particles seen as radiopaque granules. The graft particles appeared to be well-integrated and no areas of loose particles were observed. Histologic evaluation demonstrated BCP particles embedded in woven bone with dense connective tissue/marrow space. New bone growth was observed around the graft particles as well as within the structure of the graft particulate. There was intimate contact between the graft particles and newly formed bone, and graft particles were bridged by the newly formed bone in all biopsies from the tested groups. The present study results support the potential of these BCP graft particulates to stimulate new bone formation. Clinical studies are recommended to confirm these preclinical findings.

Patients with insufficient residual alveolar bone height are often treated using short implants. Historically, short implants are associated with higher failure rates. However, recent research has shown short implants with modified surfaces to have success rates similar to those of longer implants. This retrospective report aimed to evaluate clinical outcomes of 8-mm-wide diameter, moderately rough threaded implants in the posterior maxilla. From June 2008 through May 2010, 16 patients were identified who had been treated with short implants. The mean age of the patients was 50.4 years, the mean primary stability of the implants was 66 ISQ, the mean secondary stability was 75.6, and the mean loading time was 16.2 months. There were no failed implants. The mean marginal bone loss at final follow-up was 0.04 mm. This study exhibited excellent short-term clinical outcomes.

Background: Accurate recording of implant location is required so that definitive restorations are properly supported and do not place additional stresses on the implants. Movement of impression copings inside the impression material using an open-tray or close-tray impression technique during clinical and laboratory phases may cause inaccuracy in transferring the three-dimensional spatial orientation of implants intraorally to the definitive cast. Consequently, the restoration may require corrective procedures.

Aim: This in vitro study compared the accuracy of two different impression techniques with two different impression coping shapes using polyether impression material to obtain precise definitive casts.

Materials and methods: Two reference acrylic resin models (Technovits 4000, Heraeus Kulzer GmbH & Co., Wehrheim, Germany) with five internal connection implants having different shapes of impression copings (Implantium [Dentium, Seoul, South Korea] and Replace Select [Nobel Biocare AB, Göteborg, Sweden]) were fabricated. Twenty medium-consistency polyether impressions of these models were made with square and conical impression copings of each system using open-tray and close-tray techniques. Matching implant replicas were screwed into the impression copings in the impressions. Impressions were poured with type IV stone, and the positional accuracy of the implant replica heads in x-, y-, and z-axes (represented in [Δr]) and also rotational displacement (ΔΘ) were evaluated using a coordinate measuring machine (Mistral, DEA Brown&Sharpe, Grugliasco, Italy). These measurements (linear and rotational displacements) were compared with the measurements calculated on the reference resin models that served as control, and data were analyzed with a two-way analysis of variance at α = 0.05.

Results: Less inaccuracy occurred in less retentive shape impression copings (Replace Select) compared with the more retentive one (Implantium) (p(r) < .001 and p(Θ) < .001), but there was no significant difference between direct and indirect impression techniques (p(r) and p(Θ) > .05).

Conclusion: The impression coping shape had more impact on impression inaccuracy than impression technique did. Understanding of the magnitude and variability of distortion when employing certain impression-making methods and impression coping shapes helps the clinician to select a better implant component and impression technique.

The purpose of this case report was to analyze the outcome of alveolar ridge reconstruction procedures with composite alloplastic biomaterial (biphasic calcium phosphate composed of 30% hydroxyapatite and 70% Β-tricalcium phosphate) for the treatment of large alveolar ridge defects. The clinical and histologic findings demonstrated that this alloplastic biomaterial can be used to potentially regenerate large alveolar ridge defects. This composite biomaterial appears to be safe, biocompatible, and osteoconductive.

Objectives: The purpose of this study was to compare differences in the healing process in the sinus bone grafting using various grafting materials.

Study design: Maxillary sinus bone grafts were divided into 4 groups according to the graft material used: group I, a mixture of autogenous bone and BioOss (Osteohealth Co., Shirley, NY); group II, a mixture of BioOss and Orthoblast II (Greencross; Isotis); group III, BioOss only; and group IV, synthetic bone, Osteon (Genoss, Korea), only. To evaluate the healing status of the graft surgery, bone specimens were collected from the lateral sinus using a 2.0-mm trephine bur at 4 and 6 months after surgery. Histology of the bone specimens was prepared, and the percentage of newly formed bone fraction, lamellar bone/woven bone ratio (LB/WB), and newly formed bone/graft material ratio (NB/GM) were measured to indicate the suitability of the materials and the healing of the grafts.

Results: The LB/WB ratio and NB/GM ratio were markedly increased at 6 months compared with the values at 4 months. It was observed that good bone healing was achieved even for grafts of xenogeneic bone only or synthetic bone only. Cases grafted with a mixture of allogeneic and xenogeneic bone showed no great advantage regarding bone healing.

Conclusion: The results indicated that grafts of xenogeneic or synthetic bone can be effective for sinus bone grafting.

Purpose: This article attempted to determine the factors affecting the preload and screw loosening.

Methods: Available clinical studies from 1981 to 2008 from the PUBMED that presented screw loosening data and review articles regarding screw joint stability were evaluated. Eleven studies dealing the biomechanical principles of the screw mechanics were reviewed. Moreover, the results of our data were included.

Results: The frequency of screw loosening was consequently reduced due to the advancement in torque tightening with torque wrench, screw material, coating technique for reducing the frictional force, and thread design, etc. If preload in the screw falls below a critical level, joint stability may be compromised, and the screw joint may fail clinically. The types of fatigue failure of screw were divided to adhesive wear, plastic deformation, and screw fracture.

Conclusion: An optimum preload is essential to the success of the implant-abutment complex. To maintain optimum preload, using a torque wrench and re-tightening at recall time were needed.

Aim: The aim of this experimental in vivo investigation was to assess the anti-resorptive effect of low concentration pamidronate on the buccal plate in fresh extraction sockets.

Materials and methods: The distal roots of the third premolars were extracted bilaterally in six dogs. A collagen matrix loaded with either pamidronate (test group) or saline (control group) was positioned on the outer surface of buccal bone immediately after tooth extraction and subsequently covered with a coronally advanced flap. Histological and histomorphometric outcomes were evaluated 12 weeks later.

Results: The mean vertical distance between the buccal and lingual bone crest differed significantly between the test and control groups (0.52 ± 0.43 and 2.21 ± 1.15 mm, respectively; p = .037). The width of the buccal bone 1 mm below the crest was significantly wider in the test group than the control group (4.68 ± 0.68 vs. 3.44 ± 0.60 mm, p < .001).

Conclusions: Local application of pamidronate onto a collagen matrix may reduce the dimensional changes of the buccal bone plate both vertically and horizontally.

Purpose: This article attempted to determine the factors affecting the preload and screw loosening.

Methods: Available clinical studies from 1981 to 2008 from the PUBMED that presented screw loosening data and review articles regarding screw joint stability were evaluated. Eleven studies dealing the biomechanical principles of the screw mechanics were reviewed. Moreover, the results of our data were included.

Results: The frequency of screw loosening was consequently reduced due to the advancement in torque tightening with torque wrench, screw material, coating technique for reducing the frictional force, and thread design, etc. If preload in the screw falls below a critical level, joint stability may be compromised, and the screw joint may fail clinically. The types of fatigue failure of screw were divided to adhesive wear, plastic deformation, and screw fracture.

Conclusion: An optimum preload is essential to the success of the implant-abutment complex. To maintain optimum preload, using a torque wrench and re-tightening at recall time were needed.

Objectives: The aim of this study was to evaluate and compare the morphometric components and the histological properties of pristine bone and bone grafted with a biphasic ß-tricalcium phosphate in humans using the maxillary sinus model. Reparative mesenchymal stem cells in the pristine bone and graft were also evaluated.

Materials and methods: For this prospective case series, sinus augmentation was performed using a biphasic ß-tricalcium phosphate. After 6 months of healing, a core of remnant native alveolar bone and grafted bone was collected with a trephine. Histological, histomorphometrical, and immunohistochemical techniques were performed. Radiological analysis through cone beam computerized tomography was also conducted.

Results: A total of 10 patients were enrolled in this study. Radiologically, patients showed an average increase of crestal bone of 8.03 ± 1.72 mm. Morphologically, the grafted area was composed by 34.93 ± 14.68% of new mineralized tissue, 9.82 ± 11.42% of remnant biomaterial particles, and 55.23 ± 11.03% non-mineralized tissue. Histologically, we found no differences in the number of osteocytes per mm2 (p = 0.674), osteoblasts (p = 0.893), and blood vessels (p = 0.894) in the grafted area compared to the pristine bone. Differences were found on the number of osteoclasts (15.57 ± 27.50 vs. 5.37 ± 16.12, p = 0.027). The number of Musashi-1 positive mesenchymal cells (239.61 ± 177.4 vs. 42.11 ± 52.82, p = 0.027) was also significantly higher in the grafted area than in the pristine bone.

Conclusion: Biphasic ß-tricalcium phosphate is a suitable biomaterial to be used in the formation of new bone in sinus floor elevation procedures in humans, not only from the histomorphometrical point of view, but also regarding the cellular and vascular quality of the regenerated bone.

Calcium sulfate hemihydrate (CSH) powders were synthesized for use as bone cement by heat treating calcium sulfate dihydrate (CSD) powders in boiling CaCl2 solutions with various CaCl2 concentrations, ranging from 23.5 to 35.5 wt%, in order to control their morphology. All of the prepared CSH powders showed X-ray diffraction peaks corresponding to the CSH structure without any secondary phases, implying complete conversion from the CSD phase to the CSH phase. It was also observed that the concentration of CaCl2 significantly affected the morphology of the CSH powder that was synthesized. In other words, as the CaCl2 concentration was decreased from 35.5 to 23.5 wt%, the morphology notably changed from long-and-slim hexagonal rods with an aspect ratio of 5.5 to fat-and-short hexagonal columns with an aspect ratio of 1.4. This reduction in the aspect ratio led to a significant improvement in the compressive strength of the CSD cement prepared by mixing the CSH powders with water.

Purpose: The aim of this study was to evaluate 3.5 years-cumulative survival rate of implants placed on augmented sinus using Osteon, a bone graft material, and to assess the height of the grafted material through radiographic evaluation.

Methods: Twenty patients were treated with maxillary sinus augmentation and 45 implant fixtures were installed simultaneously or after 6 months healing period. The height of the augmented sinus and the loss of marginal bone were measured by panoramic and intraoral radiographs immediately after augmentation and up to 42 months (mean, 19.4 months) subsequently. Changes in the height of the sinus graft material were calculated radiographically.

Results: The cumulative survival rate was 95.56% in all 45 implants. Additionally, normal healing process without any complication was observed in all patients. The original sinus height was mean 4.3 mm and the augmented sinus height was mean 13.4 mm after the surgery. The mean marginal bone loss till 42 months was 0.52±0.56 mm. The reduced height of Osteon was 0.83±0.38 mm and it did not show significant correlation with the follow up periods (P=0.102). There were no statistically significant differences in reduced height of Osteon according to the simultaneous/delayed implantation (P=0.299) and particle size of Osteon (P=0.644).

Conclusions: It can be suggested that Osteon may have predictable result when it was used as a grafting material for sinus floor augmentation.

Purpose: The objective of this study was to clinically evaluate the use of OSTEON as a sinus graft material and to measure the effect of healing at 4 and 6 months after surgery.

Materials and methods: After sinus graft using OSTEON in 17 patients, bone specimens were collected from lateral sinus using 2.0-mm trephine bur at the time of 4 or 6 months after surgery. Histology of the bone specimens was prepared and the percentage of newly formed bone fraction, lamellar bone/woven bone ratio (LB/WB), and newly formed bone/graft material ratio (NB/GM) were measured to indicate the suitability of the materials and the successful healing of the graft.

Results: The morphology of OSTEON was observed to be interconnected, with 77% porosity and a pore size of 300-500 microm. After implantation, the mean percentage of newly formed bone fraction after 4 months and 6 months surgery was 40.6 and 51.9%, respectively. Statistical analysis indicated no significant difference (p = 0.135) in the newly formed bone fraction between the two postoperative periods. The mean LB/WB ratio after 4 months and 6 months surgery was 0.14 and 0.45, respectively, with significant difference observed between the two postoperative periods (p = 0.027). Additionally, the mean NB/GM ratio after 4 months and 6 months surgery was 1.95 and 7.72, respectively, with significant difference observed between the two postoperative periods (p = 0.046).

Conclusion: It was concluded that OSTEON is suitable for use in sinus graft application since desirable time-dependent healing was demonstrated.