This clinical report presents a simplified surgical procedure for accessing the maxillary sinus antrum via lateral and crestal approaches, which reduces the potential for sinus membrane perforation and subsequent complications when graft materials and dental implants are placed into the sinus. Due to visual limitations, perforations and associated complications can jeopardize the success rate of the graft and the implants. While there is a lack of clinical data, clinical observations suggest that the procedure, described by the authors as lateral/crestal bone planing antrostomy, can reduce the possibility of perforation of the maxillary sinus membrane during the lateral and crestal approaches to the grafting of the maxillary sinus floor. The technique involves the use of specially designed rotary instruments that plane away the bone in thinner layers, with less chance of excess bone removal and membrane perforation.

Objective: The objectives of this study were to analyze retrospectively the long-term survival and success rates of Narrow implants (NIs) placed with various implant systems, and the association with biological and technical complications.

Material and methods: In total, 338 patients (men = 45.6%, women = 54.4%) who received 541 NIs (≤3.5 mm in diameter) for fixed prostheses were enrolled in this retrospective study. The mean marginal bone level (MMBL) change was calculated. Life table analysis with the cumulative survival rate and success rate was calculated, and biological and technical complications were evaluated.

Results: The annual MMBL change was 0.07 ± 0.20 mm. The 12-year cumulative survival (success) rates of NIs were 98.1% (91.8%) and 98.5% (93.8%) for the implant- and subject-based analysis, respectively. During the observation period up to 12 years (mean 4.9 years), six implants were lost in the maxilla, whereas three implants were lost in the mandible. Technical complications were more frequent than biological complications. Infection was the most common underlying cause of biological complications and the most frequent technical complication was decementation.

Conclusion: In conclusion, the findings of this study suggest that NIs could be used safely for narrow alveolar ridges or narrow mesiodistal spaces on the basis of their high survival rate.

Objectives: The purpose of this study was to elucidate the healing pattern of sand-blasted, large grid, acid-etched (SLA)-surfaced implants at two healing periods in a model that represents loosened implants (LIs) installed without mechanical engagement.

Material and methods: Five mongrel dogs were used, in which 20 dental implants were prepared. The implants were divided into two groups according to the absence or presence of initial mechanical engagement: LIs) and control, respectively. An oversized drill was used to prepare the implant area for the LI group. The implants were allowed to heal for 4 or 8 weeks. After the healing period, the experimental animals were sacrificed and block sections were obtained for histological analysis and histometric measurements.

Results: All implants were in intimate contact with the host bone and were without any inflammation after both 4 and 8 weeks of healing. While the mean amount of bone-to-implant contact (BIC) was constant in the control group, it tended to increase in the LI group with increasing healing period. However, neither BIC nor bone density differed significantly between the groups or with the healing period.

Conclusion: From the results of the study, it can be conjectured that the submerged and unloaded SLA-surfaced implants could result in successful osseointegration, even if the mechanical engagement was not obtained at placement of the implants.

Barrier membranes are essential biomaterials for guided bone regeneration. Due to different origin and structure of barrier membranes, singular mechanical properties and clinical behaviors can be expected. It is important to understand the physic and chemical properties of barrier membranes to select the needed biomaterial for each clinical situation. To date, no study has evaluated and compared the physicochemical properties of various families of barrier membranes. The aim of this study is to evaluate the physicochemical properties of various barrier membranes. Fifteen membranes of different origin were tested in this study. Membranes were divided into biological or synthetic origin and grouped in natural allogenic collagen, natural xenogenic collagen, cross-linked collagen and synthetic membranes. Physicochemical properties were evaluated in terms of tension, stiffness, absorption ability, pH and wettability. For the tension tests, all membranes showed similar low tension and low stiffness, especially after a 4-min hydration, except for bone laminas that showed a greater stiffness particularly in a dry status. Regarding wettability and hydration of the barrier membranes, porcine origin membranes had greater hydration; wettability was also superior in porcine derived barrier membranes and showed a faster absorption of the drop on the rough surfaces. All membranes had a stable pH, having the synthetic membranes the most stable pH when compared to physiologic. The wide variety of barrier membranes opens a debate in which the practitioner should select the adequate barrier membrane for each clinical situation. Different materials show singular potentials depending on their tissue origin making them suitable for specific clinical indications. More studies regarding adsorption, integration and degradation of barrier membranes are needed to understand their behavior.

Objectives: This study aims to determine differences in primary stability between implants placed in cortical bone following Piezoelectric or conventional site preparation, as assessed by resonance frequency analysis (RFA) and reverse torque testing (RTT).

Material and methods: Four fresh bovine ribs were acquired and surgical guides fabricated with five sites per rib (n = 20), for proper site preparation. Implant sites were prepared via conventional drilling technique as per manufacturer's instruction (Implantium) or via Piezoelectric (Mectron) implant site preparation using the Implant Prep kit. Twenty 10 mm long, 3.6 mm diameter Implantium implants were placed with 35 Ncm torque; 10 implants per preparation method. RFA was assessed via the Osstell Mentor. Five values were taken per implant. All implants where subjected to a reverse torque in increasing increments of 5 until 50 Ncm force was reached.

Results: The five RFA values per site were averaged and plotted by placement technique. A paired t-test statistical analysis was run. The average RFA values showed no statistical significance between the 10 test (RFA = 69.04 ± 5.11) and 10 control (RFA = 70.94 ± 6.41) sites (P > 0.05). All implants in both groups withstood RTT up to 50 Ncm force without movement and thus showed no statistical differences.

Conclusion: Results of this ex vivo study imply that the Piezoelectric implant site preparation affords similar primary implant stability in comparison to conventional rotary instrumentation in cortical bone.

Statement of problem: Since the introduction of the concept of osseointegration in dental implants, high longterm success rates have been achieved. Though the use of dental implants have increased dramatically, there are few studies on domestic implants with clinical and objective longterm data.

Purpose: The aim of this retrospective study was to provide longterm data on the Implantium® implant, which features a sandblasted and acid-etched surface and internal connection with microthreads.

Material and methods: 106 Implantium® implants placed in 38 patients at Yonsei University Hospital were examined to determine the effect of various factors on implant success and marginal bone loss, through clinical and radiographic results during a 6 to 30 month period.

Results: 1. Out of a total of 106 implants placed in 38 patients, one fixture was lost, resulting in a 99.1% cumulative survival rate. 2. Among the 96 implants which were observed throughout the study period, the survival rates were 97.0% in the maxilla and 100% in the mandible. The survival rate in the posterior regions was 98.9% and 100% in the anterior regions. 3. The mean bone loss during the first year after prosthesis placement was 0.17 mm, while the mean annual bone loss after the first year was 0.04 mm, which was statistically less than during the first year (P < .05). 4. There was no significant difference in marginal bone loss according to age during the first year (P> .05), but after the first year, the mean annual bone loss in patients above 50 years was significantly greater (P < .05) compared with patients under 50 years. 5. No significant difference in marginal bone loss was found according to the following factors: gender, jaw, location in the arch, type of implant (submerged or non-submerged), presence of bone grafts, type of prostheses, and type of opposing dentition (P < .05).

Conclusion: Based on these results, the sole factor influencing marginal bone loss was age, while factors such as gender, jaw, location in the arch, type of implant, presence of bone grafts, type of prostheses and type of opposing dentition had no significant effect on bone loss. In the present study, the success rate of the Implantium® implant with a SLA surface and internal connection with microthreads was satisfactory up to a maximum 30 month period, and the marginal bone loss was in accord with the success criteria of dental implants.

The purpose of this study was to determine the clinical and histologic efficacy of the combination of alloplastic biphasic calcium phosphate composed of 30% hydroxyapatite and 70% Β-tricalcium phosphate (Osteon II) and a cross-linked collagen membrane used to reconstruct an extraction socket with new bone formation. Twelve patients, from two private dental practices, requiring extraction of maxillary and mandibular nonmolar teeth (n = 30) received both Osteon II (0.5- to 1.0-mm particle size) and the collagen membrane. The primary healing intention group (group A, n = 12) received primary flap closure over the membrane, while in the secondary healing intention group (group B, n = 18), the membrane was left exposed. Early wound healing seemed to be slower in group B when compared to group A, but the difference was not noticeable after 4 weeks. Clinical reentry revealed that the dimensions of the ridge appeared to be maintained in both groups, and internal socket bone fill was evident. The grafted area appeared to be well vascularized, but clinically visible graft particles were noted in some cases. Light microscopic analysis revealed the formation of new bone directly apposing the surfaces of graft particles and bridging the space between them, indicating that the graft material behaved as an osteoconductive scaffold. The mean amount of vital bone in group A was 40.3% ± 7.8%, while the remaining graft was 6.0% ± 4.0%. The mean amount of vital bone in group B was 47.3% ± 11.3%, while the remaining graft was 18.0% ± 20.0%. The absence of primary flap closure did not affect the percentage of vital bone formation or residual graft.

Purpose: This experimental study was designed to analyze the effect of different compressive forces on the bone regeneration around a particulate bone graft material.

Material and methods: Eighty 6-mm-diameter defects were created in the calvaria of 20 New Zealand rabbits (4 defects per rabbit calvaria). All the defects were filled with particles of synthetic bone. Two standardized compressive forces were then applied, 4.1 g to half the defects (Test A) and 8.2 g to the other half (Test B), all for 1 min. The graft sites were allowed to heal for 6 weeks, after which the rabbits were euthanized. The calvarium vault of each animal was extracted, radiographed, and prepared for histomorphometric analysis. The percentage of defect fill, bone density, new bone formation, and residual bone graft material were recorded, and the results were subjected to statistical analysis.

Results: Histological evaluation found that defect closure among the Test A (lower compression) group ranged from 38.34 (95% lower CI) to 55.8 (95% upper CI) (mean 47 ± 8.5%), while among the Test B group (higher compression), it ranged from 81.26 (95% lower CI) to 95.32 (mean 88 ± 7.3%). Significantly more closure was achieved for the Test B group (P < 0.05). Histomorphometric comparison of the two groups found significantly more new bone formation, higher bone density, and a higher percentage of defect fill in the defects subjected to the higher compression level (P < 0.05).

Conclusions: Increasing the compressive force applied to bone graft particulate used to fill small defects created in rabbit calvaria appears to be beneficial.

Purpose: If less than 4 mm of residual bone is remained in posterior maxilla, two-stage operation is recommended for implant installation. However, if primary stability could be obtained using tapered designed implants, one-stage surgery could be performed with reliable success rate in severely resorbed maxilla. The purpose of this prospective study was to evaluate survival and success rates of the implants simultaneously placed into grafted sinus using rough-surfaced implant.

Materials and methods: A total of two hundred seventeen consecutive sinus lifting through lateral approach and four hundred sixty-two simultaneous implants were installed from November 2003 for 5.5 years. Xenogenic bone was used solely for bone graft materials. Second surgery was performed around 6 months after operation and porcelain fused metal or gold crown was used for definitive restorations. Cumulative survival and success rates were evaluated according to residual alveolar bone height (RABH), smoking status, and Schneiderian membrane perforation.

Results: The mean follow-up was 57.1 ± 15.6 (36-98) months. Of the four hundred sixty-two implants, two hundred sixty-two implants (56.7%: group 1) were installed in posterior maxilla less than 4-mm RABH and two hundred implants (43.3%: group 2) were placed in over 5-mm RABH. The cumulative survival and success rates were 98.91% and 96.54%. There was no statistically significant difference in success rate between group 1 and group 2 (p = .3135). Perforation of the membrane was not related to success (p = .7162), but smoking status is significantly related with implant failure (p = .0003).

Conclusions: Sinus lifting with simultaneous implant placement could be used to treat atrophic maxilla in patients with minimal RABH when initial stability could be obtained by using taper designed implants with surgical techniques. Smoking is a possible factor for implant failure. Membrane perforation did not have an adverse effect on implant success if the membrane was repaired with absorbable membrane and fibrin glue.

Objectives: The objective of this study was to clinically evaluate the use of Osteon as a sinus bone graft material and to measure the loss of sinus bone graft volume and marginal bone loss around the implants.

Study design: Thirty-two implants were placed in 16 patients after maxillary sinus bone grafting. In 7 patients, maxillary sinus bone graft was performed first and 15 implants were placed after 4 months; in 9 patients, 17 implants were placed simultaneously with maxillary sinus bone grafting. Based on medical records and radiographs, intraoperative and postoperative complications were examined, and at 1 year after the placement of the upper fixture, the success rate of implants, peri-implant soft tissue condition, and the marginal bone loss were evaluated. Additionally, the sinus bone graft volume loss was evaluated by comparing the residual alveolar bone height of the preoperative maxillary sinus floor with that immediately after the operation and after 1 year.

Results: Regarding intraoperative complications, perforation of the maxillary sinus membrane occurred in 6 cases (37.5%), and after surgery maxillary sinusitis developed in 2 cases. During the healing period, 1 implant failed in osseointegration. At the last follow-up observation, none of cases showed marginal bone loss of >1 mm and a 96.9% success rate was seen. The follow-up observation period after placement of the superstructure was 12-30 months (average 15). Between the simultaneous placement group and the delayed placement group, marginal bone loss showed no statistically significant difference (P = .455). In the entire patient group, the volume of sinus bone graft loss did not correlate with marginal bone loss (P = .568). Preoperative alveolar bone height was 0.8-8.8 mm (mean 4.64), postoperative alveolar bone height was 12-21.8 mm (mean 17.67), and the alveolar bone height 1 year after the operation was 11.2-20.8 mm (mean 16.78). Between the group with perforation of the maxillary sinus membrane and the group without, no difference in marginal bone loss was observed (P = .628). Additionally, no difference in the volume of sinus bone graft resorption between the two groups was observed (P = .970).

Conclusion: It was concluded that Osteon is suitable for use in sinus graft application.

The titanium implant surface was sandblasted with large grits and acid etched (SLA) to increase the implant surface for osseointegration. The topography of the titanium surface was investigated with scanning electron microscopy (SEM) and a profilometer. The SLA implant demonstrated uniform small micro pits (1-2 microm in diameter). The values of average roughness (R(a)) and maximum height (R(t)) were 1.19 microm and 10.53 microm respectively after sandblasting and the acid-etching treatment. In the cell-surface interaction study, the human osteoblast cells grew well in vitro. The in vivo evaluation of the SLA implant placed in rabbit tibia showed good bone-to-implant contact (BIC) with a mean value of 29% in total length of the implant. In the short-term clinical study, SLA implants demonstrated good clinical performance, maintaining good crestal bone height.

A basic tenet of successful osseointegration is that the implant resides in a sufficient quality and quantity of bone to ensure bone contact and thus stabilization. A prospective, randomized controlled preclinical trial was conducted to evaluate the bone-to-implant contact (BIC) when placing implants in bone regenerated by 3 different combinations of biphasic calcium phosphate (BCP). Dental implants were placed into the regenerated ridges of 6 female foxhounds; the ridges were reconstructed with different formulations of BCP in combination with an hydroxyapatite collagen membrane. They were retrieved after 3 months to perform light microscopic and histomorphometric analyses. Implants in each group appeared to be stable and osseointegrated. Light microscopic evaluation revealed tight contacts between the implant threads with the surrounding bone for all 4 groups. The mean BIC ranged from 64.7% to 73.7%. This preclinical trial provided clinical and histologic evidence to support the efficacy of all 3 formulations of BCP to treat large alveolar ridge defects to receive osseointegrated dental implants.

This case series aimed to investigate the initial-phase bone remodeling during implant wound healing and to discuss the possible contributing factors. A total of 11 implants with polished collars were placed in premaxillary regions via flapless approach with the aid of computer technology. After 15 months of follow-up, the results suggested that the presence of polished collars triggered bone resorption via a bone remodeling mechanism. The overall vertical crestal resorption was 0.78 ± 0.46 mm on average. This initial-phase bone remodeling primarily occurred within the first 3 months postoperatively. The slightly exposed polished collar may not worsen crestal bone level.

Transcrestal sinus membrane elevation is a surgical procedure performed to increase the bone volume in the maxillary sinus cavity. Because of visual limitations, the potential for maxillary sinus membrane perforations may be greater than with the lateral approach technique. The aim of this study was to macroscopically investigate ex vivo the occurrence of sinus membrane perforation during surgery using 3 transcrestal sinus floor elevation methods. Twenty fresh human cadaver heads, with 40 intact sinuses, were used for simultaneous sinus membrane elevation, placement of graft material, and dental implants. Real-time sinus endoscopy, periapical digital radiographs, and cone-beam computerized tomography (CBCT) images were subsequently used to evaluate the outcome of each surgical procedure. Perforation rates for each of the 3 techniques were then compared using a significance level of P < .05. No statistically significant differences in the perforation rate (P = .79) were found among the 3 surgical techniques. Although the sinus endoscope noted a higher frequency of perforations at the time of implant placement as compared with instrumentation or graft insertion, the difference was not statistically significant (P = .04). The CBCT readings were judged to be more accurate for identifying evidence of sinus perforations than the periapical radiographs when compared with the direct visualization with the endoscope. This pilot study demonstrated that a sinus membrane perforation can occur at any time during the sinus lift procedure, independent of the surgical method used.

Statement of problem: Implant drivers are getting popular in clinical dentistry. Unlike to implant systems with external hex connection, implant drivers directly engage the implant/abutment interface. The deformation of the implant/abutment interface can be introduced while placing an implant with its implant driver in clinical situations.

Purpose: This study evaluated the change of rotational freedom between an implant and its abutment after application of different insertion torques.

Material and methods: Three kinds of internal connection implants were utilized for the current study (4.5 × 12 mm Xive, 4.3 × 11.5 mm Inplant Magicgrip, 4.3 × 12 mm Implantium MF). An EstheticBase, a 2-piece top, a Dual abutment was used for its corresponding implant system. The rotational freedom between an implant and its abutment were measured before and after applying 45, 100 Ncm insertion torque. Repeated measures ANOVA was used for statistical analysis.

Results: Under 45 Ncm insertion torque, the rotational freedom between an implant and its abutment was significantly increased in Xive (P = .003). However, no significant change was noted in Inplant Magicgrip and Implantium MF. Under 100 Ncm torque, both in Xive (P = .0005) and Implatium MF (P = .03) resulted in significantly increased rotational freedom between the implant and its abutment.

Discussion: The design of the implant/implant driver interface effectively prevented the deformation of implant/abutment interface. Little change was noted in the rotational freedom between an implant and its abutment, even though the insertion torque was far beyond clinical application.

Conclusions: The implant/abutment joint of internally connecting implants were quite stable under insertion torque in clinical situation.