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ABSTRACT: Dental implants have proven to be a reliable modality for the rehabilitation of missing teeth. However, there are limited reports on managing anodontia related to ectodermal dysplasia in the scientific literature. The severely reduced bone quantity due to the congenital absence of multiple natural teeth is the biggest challenge for the surgeon. There are a variety of bone augmentation procedures to establish adequate bone quantity, and the surgical planning should be used on an individual case basis. This is a report of a 19-year-old male patient affected by hypohidrotic ectodermal dysplasia. Oligodontia associated with severe atrophy of jaws was the chief complaint for seeking treatment. Based on clinical and radiographic examinations, 2 bone augmentation procedures were used to obtain sufficient width of alveolus for implant placement by performing an onlay bone graft in the maxilla and vertical distraction osteogenesis in the mandible. The treatment planning was discussed and informed consent was obtained.
Implant dentistry 08/2011; 20(5):328-30. · 1.51 Impact Factor
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ABSTRACT: This study investigated the hypothesis that a mesenchymal stem cells (MSC)-implant complex could be used in type 2 diabetic rats. Diabetes was modeled with type 2 diabetic rats induced by high fat diet with low dose streptozotocin (STZ) injected intraperitoneally. MSC sheets were harvested from culture flasks, wrapped around implants to construct the complexes, and then cultured in an osteogenic medium. The layered cell sheets integrated well with the implants and remained viable, with small mineralized nodules visible on the implant surfaces after culturing. The MSC-implant complexes were inserted into the right tibiae of the diabetic rats. Titanium implants served as controls. After four and eight weeks of healing, the tibiae were observed via MicroCT and harvested for histological examination. For the MSC-implant complexes, MicroCT analysis showed that bone volume ratio and trabecular thickness increased significantly (p<0.05), and trabecular separation decreased significantly (p<0.05) compared to the titanium implants in diabetic rats. Histological examination revealed a greater amount of new bone tissue forming around the MSC-implant complexes and a higher bone implant contact (BIC) rate than the titanium implants. These findings demonstrate that MSC-implant complexes possess osteogenic abilities and can be used in diabetic rats to improve the BIC rate. Thus, MSC-implant complexes provide a novel tissue engineering approach that promotes osseous healing and may potentially be useful in the treatment of diabetic patients.
Bone 06/2011; 49(3):387-94. · 4.02 Impact Factor
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ABSTRACT: In patients with type 2 diabetes mellitus (DM) there is poorer quality osseointegration than in other patients, and the success of oral implants is less. The aim of the present study was to investigate the influence of local infiltration of insulin at the implant-bone interface after implantation in diabetic rats. We used GK rats (8-week-old Goto-Kakizaki Wistar rats, n=20) in a newly established model of type 2 DM, and Sprague-Dawley rats were used as controls (n=10). GK rats were divided into two groups: those with DM alone and those with DM given insulin (INS) (n=10 in each group). The INS group was given controlled-release insulin at the implant-bone interface. Rats were killed at 2 and 6 weeks after implantation. We evaluated bone-implant contact and bony volume in all rats. Implant-bone contact, osteoid and osteogenic volume, and the amount of newly formed bone in the DM group were significantly less than in the control (p<0.05) and INS (p<0.01) groups. Implant-bone contact in the INS group was less than that in the control group, but the amount of newly formed bone was greater. In conclusion, we suggest that although the implant-bone contact in the INS group did not reach the control level, direct infiltration of insulin could improve implant-bone contact. Local infiltration of insulin at the implant-bone interface may have important clinical implications by naturally improving the success of oral implantation in diabetic rats.
British Journal of Oral and Maxillofacial Surgery 04/2011; 49(3):225-9. · 1.95 Impact Factor
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ABSTRACT: To evaluate the effect of the local delivery of basic fibroblast growth factor 2 (bFGF-2) on the osseointegration around titanium implant of diabetic rats.
The bFGF-2-loaded poly (lactic-co-glycolic acid) microspheres were prepared by water/oil/water (W/O/W) double-emulsion solvent evaporation method. Thirty-five male SPF level Sprague Dawley rats, weighing 220-250 g and aged 9 weeks, were selected as experimental animals. Ten rats were fed with the routine diet as normal control group. The other 25 rats were made the diabetic animal model by giving high fat-sugar diet and a low dose streptozotocin (30 mg/kg) intravenously; 20 rats were made the diabetic animal model successfully. Then 20 rats were randomly divided into diabetic control group (n = 10) and bFGF-2 intervention group (n = 10). A hole was drilled in the right tibia bone of all rats, and the titanium implant treated by micro-arc oxidation surface was planted into the hole. Simultaneously, the previously prepared microspheres and blood were mixed and were loaded on the surface of the implant before it was implanted into the rats of the bFGF-2 intervention group. At 4 and 8 weeks, the tibia containing implants was harvested, embedded with resin and made undecalcified tissue slices to compare the osseointegration.
At 4 weeks, the implants of the normal control group were surrounded by new lamellar bone with continuity; whereas the tissue around the implants of the diabetic control group contained little woven bone and some fibrous tissue; and obvious new formed bone with continuity was observed in bFGF-2 intervention group. At 8 weeks, the results of 3 groups were similar to those at 4 weeks. At 4 weeks, the percentage of bone-implant contact (BIC) in diabetic control group was significantly less than those in normal control group (P < 0.05) and in bFGF-2 intervention group (P < 0.05); the BIC in bFGF-2 intervention group was less than in normal control group, but showing no significant difference (P > 0.05). After 8 weeks, the BIC in normal control group and in bFGF-2 intervention group were significantly greater than that in diabetic control group (P < 0.05), but there was no significant difference between bFGF-2 intervention group and normal control group (P > 0.05).
Local delivery of bFGF-2 around titanium implants may improve the osseointegration in diabetic rats.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 03/2011; 25(3):349-53.
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Wei Zhou,
Chun Han, Yingliang Song,
Xingrong Yan,
Dehua Li,
Zhiguo Chai,
Zhihong Feng,
Yan Dong,
Liwen Li,
Xing Xie,
Fulin Chen,
Yimin Zhao
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ABSTRACT: This study investigated the hypothesis that cell sheets composed of multilayered rabbit bone marrow derived mesenchymal stem cells (MSC) could be assembled with two kinds of implants (surface-modified titanium and zirconia) for the construction of a MSC-implant. The MSC sheets were harvested from culture flasks, wrapped around implants to construct the complexes, and then cultured in osteogenic medium. The layered cell sheets integrated well with implants and remained viable, with small mineralized nodules visible on the implant surfaces for up to four weeks after culture. Cells on the implants underwent classical in vitro osteogenic differentiation with an associated elevation of alkaline phosphatase activity and bone- and vascular-related protein expression. In vivo, two kinds of cell sheet-implant complexes were transplanted under the skin of SCID mice and cultured for eight weeks. For the MSC sheet titanium implant complex, histological examination revealed that new bone tissue that formed around implants followed a predominantly endochondral pathway, exhibiting histological markers of native bone; for the MSC sheet zirconia implant complex, however, intramembranous ossification appeared to occur on the surface of the zirconia implant, as observed with typical osteocytes embedded in dense matrix and accompanied by both microvessels and marrow cavities. These findings demonstrate that MSC-implants possessing osteogenic and vascularization abilities can be produced using cell sheet engineering techniques in conjunction with routine implant materials, which provide a novel technology to modify the implant surface.
Biomaterials 04/2010; 31(12):3212-21. · 7.40 Impact Factor
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Chun Han,
Zhenhua Yang,
Wei Zhou,
Fang Jin, Yingliang Song,
Yinxiong Wang,
Na Huo,
Lei Chen,
Hong Qian,
Rui Hou,
Yinzhong Duan,
Yan Jin
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ABSTRACT: Mesenchymal stem cell (MSC)-mediated tissue regeneration offers opportunities to regenerate a bio-root and its associated periodontal tissues to restore tooth loss. Previously, we proved that the apical end of developing root was acting as a promising candidate cell source for root/periodontal tissue (R/PT) regeneration. In the present study, we investigated the properties of periapical follicle stem cells (PAFSCs) isolated from the apical end of developing root of human third molars at the root-developing stage and evaluated the potential application of these cells for cementum/periodontal ligament (PDL) regeneration and bio-root engineering. Putative PAFSCs were isolated and subcultured until 20th passage. Cell characteristics of PAFSCs at early or late passage were evaluated and compared with periodontal ligament stem cells (PDLSCs) via a series of histological, cellular, and molecular analyses. PAFSCs at early passage presented crucial stem cell properties and showed a higher proliferation rate than PDLSCs in vitro. Meanwhile, PAFSCs also showed the tissue-regenerative capacity to produce a typical cementum/PDL-like complex in vivo. During long-term passage, both cell populations changed in morphology and gradually lost their stem cell properties. The alkaline phosphatase (ALP) activity and expression of mineralization-related genes markedly declined as more passages were carried out, which might lead to the loss of tissue-regenerative capacity of these 2 groups of cells in vivo. Our findings suggest that developing tissue-derived PAFSCs are a distinctive cell population from PDLSCs and might be a promising candidate for bio-root engineering.
Stem cells and development 12/2009; 19(9):1405-15. · 4.15 Impact Factor
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ABSTRACT: Some cases of retrograde peri-implantitis arise from adjacent natural teeth that have peri-radicular infection. The present study was designed to investigate the incidence of retrograde peri-implantitis from adjacent teeth with endodontic treatment.
One hundred and twenty-eight patients of ages ranging from of 24-61 years were recruited for this study. A total of 128 ITI SLA implants with adjacent teeth that had received endodontic treatment at least 1 week before were placed in 128 patients. The date of endodontic therapy and the pulp status of the adjacent tooth before endodontic therapy were recorded. The distance between the implant and the adjacent tooth was determined using a radiograph. The stability of all implants was tested by OSSTELL and recorded at implant placement, after 4 and 12 weeks.
The incidence of retrograde peri-implantitis was 7.8%. The duration from endodontic-treated adjacent teeth to implant placement was 12.15+/-10.1 weeks, and the distance between the implant and the adjacent teeth was 2.99+/-1.4 mm. Distance and time were found to be related to retrograde peri-implantitis (P<0.05). The stability of implants with retrograde peri-implantitis was less than that of the normal implants, but the difference was not significant (P>0.05).
The incidence of retrograde peri-implantitis may reduce by increasing the distance between the implant and adjacent tooth, and/or the duration from endodontically treated adjacent tooth-to-implant placement. Although preliminary, these data might orient the practitioner to avoid retrograde peri-implantitis.
Clinical Oral Implants Research 09/2009; 20(12):1326-32. · 2.51 Impact Factor
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ABSTRACT: The objectives of the present study were (1) to compare the stability of delayed loaded (DL) and immediately loaded (IL) ITI SLA implants during the first 3 months of the healing period using resonance frequency analysis (RFA) and (2) to determine the factors that affect implant stability during the healing period.
To compare implant stability, RFA was performed on two groups of patients (12 patients received 25 IL implants and 47 patients received 79 DL implants) with a total 104 ITI SLA implants. Implant stability was measured directly by RFA at implant placement and consecutively once a week for 12 weeks. Statistical analyses were carried out to study implant stability differences between IL and DL groups.
One of the 25 implants in the IL group failed, and no implant was lost in the DL group. Implant stability between the IL and DL groups showed a statistically significant difference (P<0.05). The mean implant stability quotient of all measured implants from implant insertion to 12 weeks was 72.88 +/- 5.39 for the DL and 75.86 +/- 3.60 for the IL types. The lowest stability was at 4 weeks for DL implants (mean: 71.58 +/- 5.11) and 2 weeks for IL implants (mean: 71.33 +/- 2.97). In both groups, bone types I and II showed higher implant stability than bone type III (P<0.05).
The findings of this study indicate that differences in osseointegration between IL and DL implants may be predicted according to differential implant stability.
Clinical Oral Implants Research 09/2009; 20(12):1360-6. · 2.51 Impact Factor
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ABSTRACT: It was recognized that periodontal progenitor cells penetrate disintegrated Hertwig's epithelial root sheath, and contact with root dentin give rise to periodontium formation. Clinically, direct contact of the conditioned or denuded root surfaces with periodontal cells seems to be a prerequisite for periodontal regeneration. In this study, we investigated the biological effect of dentin noncollagenous proteins (DNCPs) on the human periodontal ligament stem cells (HPDLSCs) in vitro and in vivo. Chemical-conditioned root dentin (CCRD) was prepared by process of partly demineralization and deproteinization. Treated HPDLSCs with DNCPs showed increased proliferation and adhesion ability. Induced HPDLSCs presented several features of cementoblast differentiation, as indicated by morphologic changes, enhanced alkaline phosphatase (ALP) activity, increased matrix mineralization, and upregulated expression of mineralization-associated genes. Incubation of treated HPDLSC aggregate in vivo revealed that cementum-like tissues formed along the CCRD surface with fibrous tissue adjacent to or inserted into it, but untreated HPDLSCs cannot form similar structure. To our knowledge, this is the first study to apply active proteins derived from dentin with periodontal stem cells to construct periodontal structure, which may shed light on human periodontal tissue regeneration.
Tissue Engineering Part A 11/2008; 14(12):2059-68. · 4.64 Impact Factor
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ABSTRACT: The objective of this study was to investigate the tarnish induced by Streptococcus sobrinus serotype g on Co-Cr, Ni-Cr and casting titanium alloys.
Co-Cr, Ni-Co and casting titanium alloys were respectively machined into a size of 10 mm x 10 mm x 1 mm in tablets, and totally 90 specimens with 30 of each were prepared for the test. The 30 specimens of each alloy were randomly and equally divided into three subgroups, including the blank control group, the media control group and the inoculated media group. Under the aerobic condition, the surfaces of the sucrose agar media were inoculated with Streptococcus sobrinus serotype g. The labeled sterile specimens were placed on the surface of the media for 10 weeks. The specimens were changed to a new sucrose media with bacteria each week. The specimens were removed after 10 weeks of incubation, immersed in 0.05% glutaraldehyde solution to eliminate AaY4, rinsed with distilled water. After 2 weeks, the specimens were removed and observed visually or examined by MINOLTA CR-100 color apparatus.
Compared with the blank control, the control media without bacteria did not influence the alloy specimens (P > 0.05). Streptococcus sobrinus serotype g caused tarnish on specimens. There was significant difference between the control media group and the blank control group with inoculated media group on all the specimens (P < 0.05).
Streptococcus sobrinus serotype g affects the color of Co-Cr, Ni-Cr and casting titanium alloys, but the color does not change from yellow-green range to red-yellow range.
Hua xi kou qiang yi xue za zhi = Huaxi kouqiang yixue zazhi = West China journal of stomatology 02/2002; 20(1):14-7.
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ABSTRACT: To evaluate continuous and simultaneous variations of thread height and width for an experimental screw-type implant.
A finite element model of an implant with a V-shaped thread was created. The range of thread height was set at 0.20 to 0.60 mm, and the range of thread width was set at 0.10 to 0.40 mm. Forces of 100 N and 50 N were applied along the implant axis (AX) and an angle of 45 degrees in a buccolingual direction (45-degree BL), respectively. The maximum von Mises stresses in jawbone were evaluated, and the sensitivity of the stress in jawbone to the variables was also evaluated.
Under AX load, the maximum von Mises stresses in cortical and cancellous bones increased by 4.3% and 63.0%, respectively, as thread parameters changed. Under 45-degree BL load, maximum von Mises stresses in cortical and cancellous bones increased by 19.3% and 118.0%, respectively. When thread height was from 0.34 to 0.50 mm and thread width was 0.18 to 0.30 mm, the tangent slope of the maximum von Mises stress response curve ranged from -1 to 1. The variation of the maximum von Mises stresses in jawbone was more sensitive to thread height than to thread width.
Stress in cancellous bone is more likely to be influenced by thread parameters than stress in cortical bone. A 45-degree BL force is more likely to be influenced by thread parameters than an axial force. A thread height of 0.34 to 0.50 mm and a thread width of 0.18 to 0.30 mm is optimal from a biomechanical point of view. In the design of a screw-type implant, thread height is more important than thread width for the reduction of stress within the bone.
The International journal of oral & maxillofacial implants 23(1):65-74. · 1.78 Impact Factor
