• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.3
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• pp.276-281
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• 2010

The maxillary posterior area is the most challenging site for the dental implant. After missing of teeth on maxillary posterior area due to periodontal problems, the remaining alveolar ridge is usually very thin because of not only pneumatization of maxillary sinus but also destruction of alveolar bone. The maxillary sinus bone graft procedure is one of the most predictable and successful treatments for the rehabilitation of atrophic and pneumatized endentulous posterior maxilla. But, in case of severe destruction of alveolar bone due to periodontal problems, very long crown length is still remaining problem after successful sinus graft procedures. We performed vertical augmentation of maxillary posterior alveolar ridge using mandibular ramal block bone graft with simultaneous sinus graft. After this procedures, we could get more favorable crown-implant ratio of final prosthodontic appliance and more satisfactory results on biomechanics. This is a preliminary report of the vertical augmentation of maxillary posterior alveolar ridge using mandibular ramal block bone graft with simultaneous sinus graft, so requires more long-term follow up and further studies.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.4
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• pp.337-343
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• 2010

Purpose: By reviewing literature on the subject, we compared the survival rate of implants placed in various graft materials used for maxillary sinus augmentation. Materials and Methods: The search protocol used the Pubmed electronic database, with a time limit from 1998 to 2009. Keywords such as 'sinus lift,' 'sinus augmentation,' 'sinus floor elevation,' 'sinus graft,' 'bone graft,' 'implants,' 'oral implants,' and 'dental implants' were used, alone and in combination, to search the database. We selected articles and divided them into three groups by type of graft materials: Group 1. Autogenous bone group: autogenous bone alone; Group 2. Combined bone group: autogenous bone in combination with bone substitutes; and Group 3. Substitute group: bone substitutes alone or bone substitute combinations. Results: We selected 37 articles concerning a total of 2,257 patients and 7,282 implants; 417 implants failed. The total implant survival rate (ISR, %) was 94.3%. In Group 1, 761 patients and 2,644 implants were studied; 179 implants failed and the ISR was 93.2%. In Group 2, 583 patients and 1,931 implants were studied; 126 implants failed and the ISR was 93.5%. In Group 3, 823 patients and 2,707 implants were studied; 112 implants failed and the ISR was 95.9%. Conclusion: Implants inserted in grafts composed of bone substitutes alone or in grafts composed of autogenous bone in combination with bone substitutes may achieve survival rates better than those for implants using autogenous bone alone (P<0.05).

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.4
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• pp.278-288
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• 2014

Purpose: The aim of the study was to evaluate preprosthetic initial survival rate and factors associated with survival of osseointegrated implants placed in edentulous area of maxilla and mandible and to suspect the possible causes leading to failure. Materials and Methods: A total of 2158 endosseous implants that had been inserted between 2004 through 2013 were placed in 770 patients. The clinical comparisons were performed to evaluate implant loss in relation to age and gender of patients, position, system, length and diameter of implant, and bone graft technique. Results: According to position, the survival rates were 98.23% in maxillary anterior site, 96.98% in maxillary posterior site, 97.85% in mandibular anterior site and 98.76% in mandibular posterior site (P < 0.05). According to diameter of implant, the survival rates were 100% under 3.0 mm, 97.09% between 3.0 to 3.5 mm, 98.19% between 3.5 to 4.0 mm and 98.29% between 4.0 to 4.5 mm but relatively lower survival rate was 75% in 5.0 mm-over (P < 0.05). The survival rates of implants were 89.51%, 98.28%, 98.34% and 99.27% in the group with isolated sinus graft, with isolated GBR, with sinus graft and GBR simultaneously and without bone graft, especially (P < 0.05). Conclusion: This study establishes a relationship between survival rate of implant and position, diameter of implant system and bone graft technique. In conclusion, there were low survival rates in maxillary posterior site, in dental implants with wide diameter of 5 mm-over, and in the group with isolated sinus graft.

• The Journal of Advanced Prosthodontics
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• v.16 no.4
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• pp.231-243
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• 2024

PURPOSE. The objective of the study was to analyze the impact of cement, bonding pretreatment, and ceramic abutment material on the overall color results of CAD-CAM ceramic crowns bonded to titanium-based hybrid abutments. MATERIALS AND METHODS. For single implant restoration of a maxillary lateral incisor a total of 51 CAD-CAM-fabricated monolithic lithium disilicate crowns were fabricated and subsequently bonded onto 24 lithium disilicate Ti-base abutments, 24 zirconia Ti-base abutments and 3 resin abutment replicas as a control group. The 48 copings were cemented with three definitive and one provisional cement on both grit-blasted and non-blasted Ti-bases. The color of each restoration and surrounding artificial gingiva was measured spectrophotometrically at predefined measuring points and the CIELAB (ΔE_ab) color scale values were recorded. RESULTS. The color outcome of ceramic crowns bonded to hybrid abutments and soft tissues was affected differently by cements of different brands. Grit-blasting of Ti-bases prior to cementing CAD-CAM copings affected the color results of allceramic crowns. There was a significant difference (P = .038) for the median ΔE value between blasted and non-blasted reconstructions at the cervical aspect of the crown. Full-ceramic crowns on zirconia Ti-base abutments exhibited significantly lower ΔE values below the threshold of visibility (ΔE 1.8). In all subcategories tested, the use of a highly opaque temporary cement demonstrated the lowest median ΔE for both the crown and the artificial gingiva. CONCLUSION. Various cements, core ceramic materials and airborne particle abrasion prior to bonding can adversely affect the color of Ti-base supported ceramic crowns and peri-implant soft tissue. However, zirconia CAD-CAM copings and an opaque cement can effectively mask this darkening.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.2
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• pp.157-164
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• 2024

A variety of digital technologies are being used throughout the entire implant treatment process of diagnosis, surgery, impression, design, and fabrication of prostheses. In this case, using a digital surgical guide, sinus floor elevation was performed without complications, and the implants were placed in the planned position. After the healing period for osseointegration, CAD-CAM (Computer-aided design-Computer-aided manufacturing) customized abutments and provisional prostheses were delivered. While using the provisional prosthesis, occlusal change was observed. To transfer the intermaxillary relationship and abutment position that reflect occlusal change and axial displacement, double scanning and abutment-level digital impressions were taken. Abutment superimposition was used to capture the subgingival margin without gingival retraction. Then, the definitive prosthesis was designed and fabricated with digital system. We report a case applying digital system, to achieve the predictable result as well as the efficient treatment process from implant surgery to fabricating prosthesis in the posterior area.

• Journal of Periodontal and Implant Science
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• v.54 no.4
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• pp.265-279
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• 2024

Purpose: The aim of current study was to evaluate percentage root coverage (RC%) in isolated Miller class III/RT2 labial gingival recession (GR) associated with malaligned mandibular anteriors, using interdisciplinary periodontal-orthodontic treatment as compared to mucogingival surgery alone. Methods: Thirty-six systemically healthy patients having isolated Miller class III/RT2 GR with respect to malaligned mandibular anteriors, were randomly divided into test group: mucogingival surgery using subepithelial connective tissue graft followed by orthodontic treatment and control group: mucogingival surgery alone. Primary clinical parameters included (RC%), recession depth, keratinized tissue width, mid-labial clinical attachment level, interdental clinical attachment level (iCAL), periodontal phenotype (PP), gingival thickness (GT), root coverage esthetics score (RES) and hypersensitivity. Total duration of follow up was 12 months. Results: Mean RC% was significantly more achieved in test group (66.67%±40.82%) in comparison to control group (39.93%±31.41%) at the end of study (P=0.049). Further, complete root coverage was attained in 5/8 cases of test group versus 1/2 cases of control group after 3/12 months respectively. RES and hypersensitivity, showed statistically significant improvement after complete follow up period in both the groups. An ideal RES score of 10 was achieved in 4/7 cases of test group while in 1/2 cases of control group after 3/12 months respectively. Correlation analysis revealed significant negative correlation between RC% and iCAL. Correlation of RC% with GT and PP was non-significant. Conclusions: Interdisciplinary periodontal-orthodontic approach may be more beneficial in terms of achieving improved RC%, esthetic and resolution of hypersensitivity in the management of Miller class III/RT2 GR in malaligned mandibular anteriors.

• Journal of Periodontal and Implant Science
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• v.44 no.5
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• pp.216-221
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• 2014

Purpose: This retrospective study compares the amount of bone resorption around implants between an autogenous tooth bone graft (AutoBT) and a synthetic bone graft after a bone-added crestally approached sinus lift with simultaneous implant placements. Methods: In all, 37 patients participated in this study. Seventeen patients were grouped as group I and underwent an AutoBT-added sinus lift using the crestal approach. The remaining 20 patients were grouped as group II and underwent synthetic bone grafting. Both groups received the implant placements simultaneously. Of the 37 participating patients, only 22 patients were included in the final results: Eleven patients of group I and 11 patients of group II. Before the surgery, the distance from the alveolar crest to the sinus floor was measured using panoramic radiography. After the surgery, the distance was measured again from the neck of the implant thread to the most superior border of the added graft materials. Then, the amount of sinus lift was calculated by comparing the two panoramic radiographs. After a year, a panoramic radiograph was taken to calculate the resorption of the bone graft material from the radiograph that was taken after the surgery. The significance of the resorption amount between the two types of graft materials was statistically analyzed. Results: The bone height was increased to an average of 4.89 mm in group I and 6.22 mm in group II. The analysis of panoramic radiographs 1 year after the surgery showed an average bone resorption of 0.76 mm and 0.53 mm, respectively. However, the degree of lifting (P=0.460) and the amount of bone-grafted material resorption (P=0.570) showed no statistically significant difference. Conclusions: Based on this limited study, AutoBT can be considered a good alternative bone graft to a synthetic bone graft in a bone-added sinus lift, when extraction is necessary prior to the surgery.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.3
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• pp.314-324
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• 2006

Statement of problem. Osseointegration is important mechanism of dental implant but it is not easy to evaluate. Indirect measurement is non-invasive and clinically applicable but they need more study about correlation between indirect values and degree of osseointegration. Purpose. The aims of this study were to evaluate the coefficient of correlation between indirect measurement and direct measurement under different healing time, and assessment of effect of initial insertion torque to the implant stability. Material and Methods. 20 rabbits received 3 implants on each side of tibia. Three kinds of implants (machined surface implant, Sandblasted with Large grit and Acid etched implant, Resorbable Blast Media treated implant) were used. During the surgery implant insertion torque were measured with $Osseocare^{TM}$. After the 1, 4, 8, 12 weeks of healing time, animals were sacrificed and stability values (Implant Stability Quotient with $Osstell^{TM}$, removal torque with torque gauge) were measured. Results. The Bone quality of rabbit tibia was classified into 2 groups according to the insertion torque. Resonance frequency analysis (ISQ) and removal torque showed positive correlation until $4^{th}$ week (r=0.555, p=0.040). After $8^{th}$ week (r=0.011, p=0.970) the correlation became weak and it turned negative at $12^{th}$ week (r=-0.074, p=0.801). Insertion torque and ISQ showed changing correlation upon the healing time ($1^{st}$ week: r=0.301, p=0.033, $4^{th}$ week: r=-0.429, p=0.018, $8^{th}$ week: r=0.032, p=0.865, $12^{th}$ week: r=-0.398, p=0.029). Insertion torque and removal torque has positive correlation but it was not statistically significant ($1^{st}$ week: r=0.410, p=0.129, $4^{th}$ week: r=0.156, p=0.578, $8^{th}$ week: r=0.236, p=0.398, $12^{th}$ week: r=0.260, p=0.350). Conclusion. In this study, bone quality may affect the degree of osseointegration positively during healing time and correlation between ISQ and degree of osseointegration can be different according to the healing time and bone quality.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.505-511
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• 2014

PURPOSE. The purpose of this study was to assess the effect of systemically administered oxytocin (OT) on the implant-bone interface by using histomorphometric analysis and the removal torque test. MATERIALS AND METHODS. A total of 10 adult, New Zealand white, female rabbits were used in this experiment. We placed 2 implants (CSM; CSM Implant, Daegu, South Korea) in each distal femoral metaphysis on both the right and left sides; the implants on both sides were placed 10 mm apart. In each rabbit, 1 implant was prepared for histomorphometric analysis and the other 3 were prepared for the removal torque test (RT). The animals received intramuscular injections of either saline (control group; 0.15 M NaCl) or OT (experimental group; $200{\mu}g/rabbit$). The injections were initiated on Day 3 following the implant surgery and were continued for 4 subsequent weeks; the injections were administered twice per day (at a 12-h interval), for 2 days per week. RESULTS. While no statistically significant difference was observed between the two groups (P=.787), the control group had stronger removal torque values. The serum OT concentration (ELISA value) was higher in the OT-treated group, although no statistically significant difference was found. Further, the histomorphometric parameter (bone-to-implant contact [BIC], inter-thread bone, and peri-implant bone) values were higher in the experimental group, but the differences were not significant. CONCLUSION. We postulate that OT supplementation via intramuscular injection weakly contributes to the bone response at the implant-bone interface in rabbits. Therefore, higher concentrations or more frequent administration of OT may be required for a greater bone response to the implant. Further studies analyzing these aspects are needed.

• Journal of Periodontal and Implant Science
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• v.54 no.3
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• pp.161-176
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• 2024

Purpose: Peri-implant mucositis (PIM) and peri-implantitis (PI) are multicausal conditions with several risk factors contributing to their pathogenesis. In this study, we retrospectively investigated risk variables potentially associated with these peri-implant diseases (PIDs) over a follow-up period of 1 to 18 years. Methods: The study sample consisted of 379 implants placed in 155 patients. Single-visit clinical and radiographic evaluations were employed to determine the presence or absence of PIDs. Parameters related to the patient, site, surgery, implant, and prosthetic restoration were documented. The relationships between risk variables and the occurrence of PIDs were individually examined and adjusted for confounders using multivariate binary logistic regression models. Results: The prevalence rates of PIM and PI were 28.4% and 36.8% at the patient level and 33.5% and 24.5% at the implant level, respectively. Poor oral hygiene, active gingivitis/periodontitis, preoperative alveolar ridge deficiency, early or delayed implant placement, implant length of 11.0 mm or less, and poor restoration quality were strong and independent risk indicators for both PIDs. Furthermore, a follow-up period of more than 5 years and a loading time of more than 4 years were important indicators for PI. Simultaneously, age and smoking status acted as modifiers of the effect of mesiodistal (MD) and buccolingual (BL) widths of restoration on PI. Conclusions: In this study population, oral hygiene, periodontal status, preoperative alveolar ridge status, implant placement protocol, implant length, and the quality of coronal restoration appear to be robust risk indicators for both PIM and PI. Additionally, the length of follow-up and functional loading time are robust indicators of PI. Furthermore, the potential modifying relationships of age and smoking status with the MD and BL widths of restoration may be crucial for the development of PI.