• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.285-292
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• 2008

Purpose: The present study was performed to evaluate the effect of surface treatment of the cervical area of implant on bone regeneration in fresh extraction socket following implant installation. Materials and methods: The four minipigs, 18 months old and 30 kg weighted, were used. Four premolars of the left side of both the mandible and maxilla were extracted. ${\phi}$3.3 mm and 11.5 mm long US II plus implants (Osstem Implant co., Korea) with resorbable blasting media (RBM) treated surface and US II implants (Osstem Implant co., Korea) with machined surface at the top and RBM surface at lower portion were installed in the socket. Stability of the implant was measured with $Osstell^{TM}$ (Model 6 Resonance Frequency Analyser: Integration Diagnostics Ltd., Sweden). After 2 months of healing, the procedures and measurement of implant stability were repeated in the right side by same method of left side. At four months after first experiment, the animals were sacrificed after measurement of stability of all implants, and biopsies were obtained. Results: Well healed soft tissue and no mobility of the implants were observed in both groups. Histologically satisfactory osseointegration of implants was observed with RBM surface, and no foreign body reaction as well as inflammatory infiltration around implant were found. Furthermore, substantial bone formation and high degree of osseointegration were exhibited at the marginal defects around the cervical area of US II plus implants. However, healing of US II implants was characterized by the incomplete bone substitution and the presence of the connective tissue zone between the implant and newly formed bone. The distance between the implant platform (P) and the most coronal level of bone-to-implant contact (B) after 2 months of healing was $2.66{\pm}0.11$ mm at US II implants group and $1.80{\pm}0.13$mm at US II plus implant group. The P-B distance after 4 months of healing was $2.29{\pm}0.13$mm at US II implants group and $1.25{\pm}0.10$mm at US II plus implants group. The difference between both groups regarding the length of P-B distance was statistically significant(p<0.05). Concerning the resonance frequency analysis (RFA) value, the stability of US II plus implants group showed relatively higher RFA value than US II implants group. Conclusion: The current results suggest that implants with rough surface at the cervical area have an advantage in process of bone regeneration on defect around implant placed in a fresh extraction socket.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.6
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• pp.337-342
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• 2012

Objectives: Implants connect the internal body to its external structure, and is mainly supported by alveolar bone. Stable osseointegration is therefore required when implants are inserted into bone to retain structural integrity. In this paper, we present an implant with a "wing" design on its area. This type of implant improved stress distribution patterns and promoted changes in bone remodeling. Materials and Methods: Finite element analysis was performed on two types of implants. One implant was designed to have wings on its cervical area, and the other was a general root form type. On each implant, tensile and compressive forces ($30N/m^2$, $35N/m^2$, $40N/m^2$, and $45N/m^2$) were loaded in the vertical direction. Stress distribution and displacement were subsequently measured. Results: The maximum stresses measured for the compressive forces of the wing-type implant were $21.5979N/m^2$, $25.1974N/m^2$, $29.7971N/m^2$, and $32.3967N/m^2$ when $30N/m^2$, $35N/m^2$, $40N/m^2$, and $45N/m^2$ were loaded, respectively. The maximum stresses measured for the root form type were $23.0442N/m^2$, $26.9950N/m^2$, $30.7257N/m^2$, and $34.5584N/m^2$ when $30N/m^2$, $35N/m^2$, $40N/m^2$, and $45N/m^2$ were loaded, respectively. Thus, the maximum stresses measured for the tensile force of the root form implant were significantly higher (about three times greater) than the wing-type implant. The displacement of each implant showed no significant difference. Modifying the design of cervical implants improves the strength of bone structure surrounding these implants. In this study, we used the wing-type cervical design to reduce both compressive and tensile distribution forces loaded onto the surrounding structures. In future studies, we will optimize implant length and placement to improve results. Conclusion: 1. Changing the cervical design of implants improves stress distribution to the surrounding bone. 2. The wing-type implant yielded better results, in terms of stress distribution, than the former root-type implant.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.4
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• pp.291-299
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• 2005

Objectives : It is well known that cigarette smoking is harzardous to the osseointegration of dental implant, due to the impaired wound healing accompanied by reduced alveolar bone density. The aim of this study is to evaluate the influence of cigarette smoke on the implant osseointegration by the time factor consideration. Materials and methods : Twenty-four male Spraque-Dawley rats (8 weeks, weighting 200 to 250g) were used in this study. In the experimental group, 13 rats were exposed to cigarette smoke, 8 minutes per day during 6 weeks, and 12 rats in the control group were not exposed at any time. RBM (Resorbed blasting media) surfaced implant (diameter 3.3mm, length 5.0mm, AVANA Co., Korea) was placed in the right femur of each rat. Each implant with surrounding bone was prepared with microtome (cutting band 0.2mm$^{(R)}$, EXAKT Co., Germany) after 1 day, 2, 4, 8 and 12 weeks and stained with toluidine blue (1%). Another clinical investigation of each implant was also done at each evaluation time. Results : Clinical investigation around implant fixture showed that there were no significant differences between the control and experimental group. Microscopic observation around implant fixture showed that there were significant differences between the control and experimental group at the initial stage after implant fixture installation. Experimental group showed a decreased bone to implant contact within 4 weeks compared to control group, but showed similar characteristics after 4 weeks. Conclusion : Smoking inhalation effect on the dental implant showed the impaired wound healing by vasoconstriction and decreased intramedullary blood flow at initial stage of osseointegration. This experimental results can be clinically useful to the implant surgery of smoking patients.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.407-413
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• 2014

Background Implant malposition can produce unsatisfactory aesthetic results after breast augmentation. The goal of this article is to identify aspects of the preoperative surgical planning and intraoperative flap fixation that can prevent implant malposition. Methods This study examined 36 patients who underwent primary dual plane breast augmentation through an inframammary incision between September 1, 2012 and January 31, 2013. Before the surgery, preoperative evaluation and design using the Randquist formula were performed. Each patient was evaluated retrospectively for nipple position relative to the breast implant and breast contour, using standardized preoperative and postoperative photographs. The average follow-up period was 10 months. Results Seven of 72 breasts were identified as having implant malposition. These malpositions were divided into two groups. In relation to the new breast mound, six breasts had an inferiorly positioned and one breast had a superiorly positioned nipple-areolar complex. Two of these seven breasts were accompanied with an unsatisfactory breast contour. Conclusions We identified two main causes of implant malposition after inframammary augmentation mammaplasty. One cause was an incorrect preoperatively designed nipple to inframammary fold (N-IMF) distance. The breast skin and parenchyma quality, such as an extremely tight envelope, should be considered. If an extremely tight envelope is found, the preoperatively designed new N-IMF distance should be increased. The other main cause of malposition is failure of the fascial suture from Scarpa's fascia to the perichondrium through an inframammary incision. As well, when this fixation is performed, it should be performed directly downward to the perichondrium, rather than slanted in a cranial or caudal direction.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.2.1-2.6
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• 2017

Background: All clinicians are aware of the difficulty of installing a dental implant in posterior maxilla because of proximate position of maxillary sinus, insufficient bone width, and lower bone density. This study is to examine which factors will make the implantation in the posterior maxilla more difficult, and which factors will affect the postoperative implant stability in this region. Methods: Five hundred seventy-three fixtures on the maxilla posterior were included for this study from all the patients who underwent an installation of the dental implant fixture from January 2010 to December 2014 at the Department of Oral and Maxillofacial Surgery in Pusan National University Dental Hospital (Yangsan, Korea). The postoperative implant stability quotient (ISQ) value, fixture diameter and length, presence of either bone graft or sinus lift, and graft material were included in the reviewed factors. The width and height of the bone bed was assessed via preoperative cone beam CT image analysis. The postoperative ISQ value was taken just before loading by using the OsstellTM $mentor^{(R)}$ (Integration Diagnostics AB, Gothenburg, Sweden). The t test and ANOVA methods were used in the statistical analysis of the data. Results: Mean ISQ of all the included data was 79.22. Higher initial bone height, larger fixture diameter, and longer fixture length were factors that influence the implant stability on the posterior edentulous maxilla. On the other hand, the initial bone width, bone graft and sinus elevation procedure, graft material, and approach method for sinus elevation showed no significant impact associated with the implant stability on the posterior edentulous maxilla. Conclusions: It is recommended to install the fixtures accurately in a larger diameter and longer length by performing bone graft and sinus elevation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.6
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• pp.317-321
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• 2015

Objectives: The purpose of this study is to evaluate five-year radiographic follow-up results of the Korean sandblasting with large grit, and acid etching (SLA)-treated implant system. Materials and Methods: The subjects of the study are 54 patients who have been followed-up to date, of the patients who underwent implant surgery from May 1, 2009 to April 30, 2011. In all, 176 implant placements were performed. Radiographs were taken before the first surgery, immediately after the first and second surgeries, immediately and six months after the final prosthesis installation, and every year after that. Bone loss was evaluated by the method suggested by Romanos and Nentwig. Results: A total of 176 implant placements were performed - 122 in men and 54 in women. These patients have been followed-up for an average of 4.9 years. In terms of prosthetic appliances, there were 156 bridges and 20 single prostheses. Nine implants installed in the maxillary molar area, three in the mandibular molar area and two in the maxillary premolar area were included in group M, with bone loss less than 2 mm at the crestal aspect of the implant. Of these, eight implants were single prostheses. In all, six implants failed - four in the mandible and two in the maxilla. All of these failures occurred in single-implant cases. The implant survival rate was 98.1% on the maxilla and 94.3% on the mandible, with an overall survival of 96.6%. Conclusion: Within the limitations of this study, implants with the SLA surface have a very superior survival rate in relatively poor bone environments such as the maxilla.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.3
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• pp.135-140
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• 2019

Objectives: This study sought to investigate the association between the systemic intake of proton pump inhibitors (PPI) and the early failure of dental implants. Materials and Methods: A retrospective cohort study involving 1,918 dental implants in 592 patients (69 implants in 24 PPI users and 1,849 implants in 568 nonusers, respectively) was conducted. The effect of PPI intake on the osseointegration of dental implants was evaluated using patientand implant-level models. Results: Among 24 PPI users, two patients experienced implant failure, one of whom had three and the other of whom had one failed implant, respectively. Thus, the rate of failure for this population was 8.3%. Separately, 11 nonusers each experienced one implant failure, and the failure rate for these patients was 1.9%. Fisher's exact test revealed statistically significant differences between PPI users and nonusers at the implant level (P=0.002) but failed to show any significance at the patient level (P=0.094). The odds of implant failure were 4.60 times greater among PPI users versus nonusers. Dental implants that were placed in patients using PPIs were found to be 4.30 times more likely to fail prior to loading. Conclusion: The findings of this study suggest that PPI intake may be associated with an increased risk of early dental implant failure.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.4
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• pp.383-394
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• 1997

This study was done to examine adherence of oral bacteria to titanium dental implant and to know the effective prophylactic antibiotics using an in vivo model. Three samples each of the implant material were set in an acrylic resin flange and placed in the maxillary buccal sulcus of twenty volunteers. At 6- and 54-hour intervals, each sample was placed on blood agar plate (BAP) and chocolate agar, and then they were incubated and identified. Also antibiotic susceptibility test was performed. The results obtained mere as follows ; 1. The microorganisms were chain-like Gram positive cocci and staphyline Gram positive cocci, Gram positive bacilli in order of frequency were found at 6-hour and 54-hour samples by Gram staining. 2. Streptococci was found predominantly at both 6-hour and 54-hour samples, but number of streptococci was decreased as compared to 6-hour samples. 3. There was no difference in the bacterial species adherent to implant between 6-hour and 54-hour samples. 4. All the microbes were sensitive to AMC (amoxacillin clavulanic acid), chloramphenicol, quinolone and vancomycin in the antibiotic susceptibility test. Above results suggest that streptococcus are mainly adhered to titanium implant after implant was placed in the oral cavity and AMC is the most recommendable antibiotics to prevent the peri-implant inflammation.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.2
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• pp.145-155
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• 2007

The advent of osseointegration and advances in biomaterials and techniques have contributed to increased application of dental implants in the restoration of maxillary partial edentulous patients. Often, in these patients, soft and hard tissue defects result from a variety of causes, such as infection, trauma, and tooth loss. These create an anatomically less favorable foundation for ideal implant placement. Reconstruction of the atrophic maxillary alveolar bone through a variety of regenerative surgical procedures has become predictable; it may be necessary prior to implant placement or simultaneously at the time of implant surgery to provide a restoration with a good long-term prognosis. Regenerative procedures are used for horizontal and vertical ridge augmentation. Many different techniques exist for effective bone augmentation. The approach is largely dependent on the extent of the defect and specific procedures to be performed for the implant reconstruction. It is most appropriate to use an evidenced-based approach when a treatment plan is being developed for bone augmentation cases. The cases presented in this article clinically demonstrate the efficacy of using a autogenous block graft, guided bone regeneration, ridge split, immediated implant placement technique on the atrophic maxillary area.

• Archives of Plastic Surgery
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• v.36 no.6
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• pp.767-772
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• 2009

Purpose: Among reasons for reoperations in augmentation mammoplasty, palpable implant, due to thin skin is relatively common, but not easy to correct, especially if thin skin area is wide. The capsule around the implant is a physiologic response to foreign body, naturally formed, and suitable for use as a flap because of its high vascularity. Authors report that capsular flap is very effective and successful method for correction of implant palpability in secondary breast augmentation. Methods: From September 2007 to September 2008, the capular flaps were performed on 5 patients having palpable and wrinkling breast implants due to very thin skin among the cases on whom secondary augmentation mammaplasty had been performed. After the capsular flap was elevated according to thin skin area, the capsular flap was turned down or over to cover the thin skin area and made the thin skin area thick. Results: Post - implant palpable breast wrinkling had been successfully corrected by capsular flaps and breast implants were not palpable any more during the follow - up period(average 9.2 months). All patients who suffered from deformed breast were satisfied. Conclusion: Authors suggest that the capsular flap is a ideal, effective and useful method in management of implant palpability.