UV-Mediated Photofunctionalization of Dental Implant: A Seven-Year Results of a Prospective Study.

Our objective was to evaluate the seven-year results of photofunctionalized implants placed in regular, complex, and cancer-related cases. This study was a prospective, single-center study. Photofunctionalization was performed immediately prior to implantation with Ultraviolet (UV) light for 15 minutes. The success rate of each patient group and the influential factors on implant failure were analyzed. Seventy implants in 16 patients were included. Four implants were left submerged (sleep). The seven-year success rate of 30 implants in regular cases and 21 implants in complex cases was 100%. The success rate of 15 implants in cancer-related cases was 22.2%, in which implants were placed in resection or reconstructed sites with or without pre- or postoperative radiation history. Implant stability quotient (ISQ) values increased at second-stage surgery by 3.2 in regular cases and by 21.9 in complex cases, while it decreased by -3.5 in cancer cases. Multivariate analysis indicated that bone quality, location, and cancer resection significantly influenced implant failure. A very reliable seven-year success rate was obtained by UV-photofunctionalized implants in regular and complex cases, even with significant site-development procedures. However, the success rate in cancer cases was significantly and remarkably lower, suggesting remaining challenges of pathophysiologically compromised conditions, such as bone resection, segmental defect, and radiation.

Combination with allogenic bone reduces early absorption of beta-tricalcium phosphate (beta-TCP) and enhances the role as a bone regeneration scaffold. Experimental animal study in rat mandibular bone defects.

Beta-tricalcium phosphate (beta-TCP) was grafted into rat mandibular bone defects to assess its potential as a scaffold material for bone regeneration. For this purpose, beta-TCP (TCP), allogenic bone (Allograft), and allogenic bone combined with beta-TCP (Combined) were employed as graft materials. To the left side of the graft materials in the bone defects, platelet-rich plasma (PRP) was added. The rats were sacrificed at one, three, and five weeks. Bone formation rate (BFR), remaining beta-TCP rate (RTR), beta-TCP absorption rate (TAR), whole amount of beta-TCP (WTCP), and total rate of BFR and RTR (TBR) were measured. Combined showed equivalent BFR to Allograft at five weeks, and showed higher RTR at one week and higher BFR at five weeks than TCP. Combined with PRP showed higher TAR than that without PRP at three weeks. Therefore, combination with allogenic bone showed reduced beta-TCP absorption, hence enhancing the role of beta-TCP in bone regeneration. These findings suggested that beta-TCP is a better scaffold for bone regeneration if its early absorption is reduced when used in combination with an osteogenic material.

Complications of minimally invasive tibial bone harvesting: Risk factors and treatment.

PURPOSE: The aim of this retrospective study was to analyze complications, risk factors, and corresponding treatment regarding the medial approach to harvesting tibial bone. MATERIALS AND METHODS: Consecutive cases at Yokohama City University Hospital were analyzed for complications of tibial particulated bone and marrow harvesting with the medial approach. The condition of bone marrow, duration of harvesting, and complications were evaluated. The complication rate and correlations between bone marrow conditions and duration of bone harvesting were assessed. The corresponding treatments for the complication were also observed. RESULTS: Thirty cases of tibial particulated bone and marrow harvesting for alveolar ridge or sinus floor augmentation before implant therapy from 2005 to 2014 were analyzed. Twenty-one patients had healthy bone marrow, whereas nine patients had fatty bone marrow. The duration of operation in patients who had both spontaneous pain and gait disturbance was approximately 56 minutes, which was significantly longer than that (approximately 40 minutes) in patients who had only gait disturbance (P < .05). A strong correlation between fatty bone marrow condition and bone harvesting time was seen. The correlation between bone marrow condition and bone harvesting time for fatty marrow was stronger than that for healthy marrow with a trend to significant difference (P = .082). The minor and major complication rate was 96.7% and 6.6%, respectively. Two patients showed postoperative infection on the tibia harvesting site. One of them, who had fatty bone marrow, showed methicillin-resistant Staphylococcus aureus-caused osteomyelitis of the tibia, which needed to be debrided and reconstructed with vancomycin containing bone cement. CONCLUSION: A duration of less than 40 minutes for harvesting time may decrease the risk of minor complications. Bone marrow condition influenced tibial bone harvesting duration, which may result in increasing the risk of complications. Regarding major complications, it was considered that wound protection was more important even if the marrow condition was healthy.

Prognostic factors and treatment outcomes of advanced maxillary gingival squamous cell carcinoma treated by intra-arterial infusion chemotherapy concurrent with radiotherapy.

BACKGROUND: The aim of this study was to evaluate the prognostic factors and treatment outcomes of advanced maxillary gingival squamous cell carcinoma (SCC) treated with intra-arterial infusion chemotherapy concurrent with radiotherapy. METHODS: A total of 46 patients were reviewed retrospectively in this study. The treatment schedule comprised intra-arterial chemotherapy (total, 60 mg/m2 docetaxel and 150 mg/m2 cisplatin) and three-dimensional computed tomography based, daily conventional radiotherapy (total, 60 Gy/30 fr) for 6 weeks. RESULTS: The median follow-up period was 40 months (range, 3-110 months). The 3-year overall survival and locoregional control rates for all patients were 64.3% and 84.3%, respectively. The OS rate of the patients with N0-1 was significantly higher than that of the patients with N ≥ 2 (P < .05). No grade 5 toxicities were observed. CONCLUSIONS: Intra-arterial infusion chemotherapy concurrent with radiotherapy was effective for advanced maxillary gingival SCC.

Effect of Photofunctionalization on Early Implant Failure.

PURPOSE: This study retrospectively evaluated the effects of bone density, staging strategy, implant stability, healing process, implant length, surface type, and photofunctionalization on early implant failure. MATERIALS AND METHODS: Consecutive study samples at Yokohama City University Hospital were analyzed for their early implant failure potentially influenced by patient-, surgical protocol-, and implant-related factors. Through the screening process using univariate analysis for those factors, candidate influential factors such as bone density, staging strategy, the level of initial implant stability, postoperative wound breakdown, the length of implants, the surface type of implants, and use or nonuse of photofunctionalization were selected as independent variables in forward multivariate logistic regression analysis. The odds ratio (OR) for candidate factors was calculated. RESULTS: A total of 563 implants placed in 219 patients from 2005 to 2017 were analyzed for their early implant failure. Stepwise logistic regression analysis finally identified postoperative wound breakdown (OR = 0.21) and the use of photofunctionalization (OR = 0.30) that significantly reduced the risk of early implant failure (P < .01 and P < .05, respectively). The implant failure rate was 10.0% with postoperative wound breakdown and 1.0% without it, whereas it was 4.3% without photofunctionalization and 1.3% with it. CONCLUSION: Among various patient-, surgical protocol-, and implant-related factors, the absence of postoperative wound breakdown and use of photofunctionalization significantly reduced the risk of early implant failure. It was notable that photofunctionalization, a unique, chairside measure to improve implant surfaces, was effective exclusively among implant-related factors.

Effects of Ultraviolet Photofunctionalization on Bone Augmentation and Integration Capabilities of Titanium Mesh and Implants.

PURPOSE: Ultraviolet (UV)-mediated photofunctionalization has earned considerable attention for the enhancement of the biologic capabilities of titanium. The effects of photofunctionalization on bone augmentation and gap closure were examined using titanium implants and mesh in a rat femur model. MATERIALS AND METHODS: An acid-etched titanium implant (4-mm length, 1-mm diameter) was placed in the gluteal tuberosity that resembles a knife-edge-like edentulous ridge. The lower half of the implant was located in a 2-mm-diameter defect created in the bone without cortical bone support; the upper half was exposed and covered with a titanium mesh to provide augmentation space. After 12 and 24 days of healing, specimens were subjected to microcomputed tomography (micro-CT)- and histology-based bone morphometry in three zones of analysis: augmentation, cortical bone-implant gap, and bone marrow. A biomechanical push-in test was performed to examine the strength of bone-implant integration. Photofunctionalization was performed by treating titanium implants and mesh with UV light for 12 minutes. RESULTS: Photofunctionalized titanium mesh and implants were hydrophilic, whereas untreated controls were hydrophobic. Bone volume was significantly greater in photofunctionalized implants and mesh than in untreated implants in all zones on days 12 and 24. Bone-to-implant contact of photofunctionalized implants was greater than that of untreated implants, not just in the bone marrow but also in the gap and augmented zones. The strength of osseointegration was three times greater for photofunctionalized implants than for untreated implants. CONCLUSION: Use of photofunctionalized titanium mesh and implants effectively enhanced vertical bone augmentation, cortical bone-implant gap closure, and osseointegration without innate bone support.

Implant Stability Development of Photofunctionalized Implants Placed in Regular and Complex Cases: A Case-Control Study.

PURPOSE: The objective of this study was to compare the rate of implant stability development of as-received and photofunctionalized dental implants in regular and complex cases. MATERIALS AND METHODS: Forty-nine implants (24 as-received and 25 photofunctionalized) placed in regular or complex cases (simultaneous guided bone regeneration, sinus elevation, or fresh extraction sockets) were studied. Photofunctionalization was performed by ultraviolet (UV) treatment of implants for 15 minutes using a photo device immediately prior to placement, and the generation of superhydrophilicity was confirmed. Implant stability was evaluated by measuring the implant stability quotient (ISQ) at placement (ISQ1) and at stage-two surgery (ISQ2). The rate of implant stability development was evaluated by calculating the osseointegration speed index (OSI), defined as the ISQ increase per month ([ISQ2-ISQ1]/healing time in months). The percentage of innate bone support at placement was evaluated clinically and radiographically. RESULTS: The average OSI was considerably greater for photofunctionalized implants (3.7 ± 2.9) than for as-received implants (0.0 ± 1.0). The OSI in complex cases was 4.2 ± 3.2 for photofunctionalized implants and 0.2 ± 0.9 for as-received implants. The OSI in cases with simultaneous sinus elevation was 5.5 ± 3.5 for photofunctionalized implants and 0.2 ± 1.1 for as-received implants. Photofunctionalized implants showed significantly higher ISQ2 values than as-received implants. Photofunctionalized implant ISQ2 values were greater than 60, regardless of primary stability and innate bone support at placement. In multivariate analysis including the effects of photofunctionalization, age and sex of patients, and diameter and length of implants, photofunctionalization showed the strongest influence on the OSI for both regular and complex cases, while other factors influenced the OSI only in certain conditions. CONCLUSION: Photofunctionalization accelerated the rate and enhanced the final level of implant stability development compared with as-received implants, particularly for implants placed into poor-quality bone and other complex cases. Photofunctionalization was a stronger determinant of implant stability than all the other tested implant- and host-related factors.

Development of a biointegrated mandibular reconstruction device consisting of bone compatible titanium fiber mesh scaffold.

Coating biomaterials with a thin hydroxyapatite (HA) was proven effective in enhancing bone compatibility. Segmental bone defects are considered as the most difficult defect to repair in bone regeneration therapy. We developed submicron-thin HA-coated titanium fiber mesh scaffolds to reconstruct immediately loaded segmental mandibular defects and evaluated their bone compatibility in vitro and in vivo. Human osteoblasts attachment, proliferation, and osteocalcin expression in non- and HA-coated scaffolds were evaluated. A 10-mm long segmental bone defect in a rabbit mandibular bone was reconstructed with non- or HA-coated scaffolds, which were removed at 9 and 21 weeks, to evaluate the mechanical strength of the bone-scaffold connection and the bone formation around the scaffold. Expression of osteocalcin was greater in HA-coated scaffolds. In vivo bone formation in HA-coated scaffolds was greater than that in non-coated scaffolds at 21 weeks. Newly formed bone in HA-coated scaffolds mostly restored bone continuity. Scanning electron microscopy identified strong integration of the bone and HA-coated scaffolds. The mechanical strength of the bone-scaffold connection was 3-fold greater in HA-coated scaffolds than that in non-coated scaffolds. These results suggest that a thin HA-coated titanium fiber mesh scaffold is a bone-compatible mandibular reconstruction device in immediately loaded segmental defects.

Hydroxyapatite coating for titanium fibre mesh scaffold enhances osteoblast activity and bone tissue formation.

This study investigated the bone regeneration properties of titanium fibre mesh as a tissue engineering material. A thin hydroxyapatite (HA) coating on the titanium fibre web was created using the developed molecular precursor method without losing the complex interior structure. HA-coated titanium fibre mesh showed apatite crystal formation in vitro in a human osteoblast culture. Titanium fibre mesh discs with or without a thin HA coating were implanted into rat cranial bone defects, and the animals were killed at 2 and 4 weeks. The in vivo experience revealed that the amount of newly formed bone was significantly higher in the HA-coated titanium fibre mesh than in the non-coated titanium fibre mesh 2 weeks after implantation. These results suggest that thin HA coating enhances osteoblast activity and bone regeneration in the titanium fibre mesh scaffold. Thin HA-coating improved the ability of titanium fibre mesh to act as a bone regeneration scaffold.

Osteosynthesis and simultaneous irregular trifocal distraction osteogenesis for segmental mandibular defect after tumor ablative surgery: a case report.

OBJECTIVE: This paper describes a case of secondary mandibular bone reconstruction performed to place dental implants. Osteosynthesis and simultaneous irregular trifocal distraction osteogenesis were documented. PATIENT: The patient was a 51-year-old man with recurrent ameloblastoma of the mandible. Segmental mandibulectomy for tumor ablation and immediate mandibular reconstruction were performed. Because the volume of reconstructed bone was insufficient to place dental implants, trifocal distraction osteogenesis (vertical and horizontal distraction osteogenesis) was performed. Because the mandible had lost its continuity, osteosynthesis was performed simultaneously. RESULTS: Through this procedure, the bone was well augmented. Absorption of the distracted bone was not seen. Adequate-length implants were placed. CONCLUSION: Irregular trifocal distraction osteogenesis synchronized with osteosynthesis shortened the treatment period and produced stable bone augmentation for placement of dental implants. Therefore, this procedure could be indicated for complicated segmental mandibular bone defects.

Factors influencing secondary alveolar bone grafting in cleft lip and palate patients: prospective analysis using CT image analyzer.

OBJECTIVE: To examine the effect of migration of the germ of the lateral incisor into the bone for eruption factors on bone bridge resorption. METHODS: Twenty-five subjects who underwent secondary alveolar bone graft were enrolled. The volume of the alveolar bone grafts immediately after the operation (V1), bone bridge formation 6 months postoperatively (V2), and tooth (teeth) migration into the bone bridge (Vt) were measured using a computed tomography (CT) image analyzer. Based upon these measurements, the following points were examined: (1) the correlation between the tooth-occupied ratio (Rt = Vt/V2 x 100) and the ratio of bone bridge resorption (Rv = (V1 - V2)/ V1 x 100); and (2) comparison of the tooth-occupied ratio (Rt) and the ratio of bone bridge resorption (Rv) between the groups with and without the germ of the lateral incisor. RESULTS: A significant negative correlation was found between Rv and Rt (p < .001). Comparison of Rv and Rt between the groups with and without a germ of the lateral incisor revealed that both indices were significantly higher in the former group than the latter one (p < .05). CONCLUSION: In cleft lip and palate patients with a germ of the lateral incisor, it is beneficial to carry out secondary bone grafting to the alveolar cleft at the age of 5 to 7 years, preceding eruption of the canine, in order to form a good bone bridge that will facilitate eruption of the lateral incisor and subsequent normal dentition and occlusion.