Active bone material containing modified recombinant human bone morphogenetic protein 2 induces bone regeneration in the alveolar process cleft in rabbits.

The clinical application of most materials used to fill severe bone defects is limited owing to the insufficient ability of such materials to induce bone regeneration over a long repair period. The purpose of this study was to establish a model for the alveolar process cleft in rabbits to evaluate the effect of active bone material in bone defect repair. The active bone material used in this study is a new bone repair material composed of a heterogeneous collagen membrane implanted with modified recombinant human bone morphogenetic protein 2. This proposed active bone material can specifically bind to collagen. Twenty-four young Japanese white rabbits (JWRs) were selected and randomly divided into four groups (normal, control, material, and bone morphogenetic protein groups). The alveolar process cleft model was established by removing an equal volume bone at the left maxillary position. Blood samples were collected from the JWRs 3 and 6 months after the surgery to evaluate the biocompatibility of the active bone materials. Subsequently, the skull model was established, and the appearance was observed. Imaging methods (including X-ray examination and micro-computerized tomography scanning), tissue staining, and immunohistochemistry were employed for the evaluation. The bone collagen material and active bone material exhibited high biocompatibility. In addition, the ability of the active bone material to induce bone repair and regeneration was higher than that of the bone collagen material. The active bone material exhibited satisfactory bone regeneration performance in rabbits, indicating its potential as an active material for repairing congenital alveolar process clefts in humans.

Repair of alveolar cleft bone defects by bone collagen particles combined with human umbilical cord mesenchymal stem cells in rabbit.

BACKGROUND: Alveolar cleft is a type of cleft lip and palate that seriously affects the physical and mental health of patients. In this study, a model of the alveolar cleft phenotype was established in rabbits to evaluate the effect of bone collagen particles combined with human umbilical cord mesenchymal stem cells (HUC-MSCs) on the repair of alveolar cleft bone defects. METHODS: A model of alveolar clefts in rabbits was established by removing the incisors on the left side of the upper jaw bone collagen particles combined with HUC-MSCs that were then implanted in the defect area. Blood biochemical analysis was performed 3 months after surgery. Skull tissues were harvested for gross observation, and micro-focus computerised tomography (micro-CT) analysis. Tissues were harvested for histological and immunohistochemical staining. The experiments were repeated 6 months after surgery. RESULTS: Bone collagen particles and HUC-MSCs showed good biocompatibility. Bone collagen particles combined with HUC-MSCs were markedly better at inducing bone repair and regeneration than bone collagen particles alone. CONCLUSIONS: Combining HUC-MSCs with bone collagen particles provides a simple, rapid and suitable method to fill a bone defect site and treat of alveolar cleft bone defects.

[Computer-assisted implant restoration of free-end partially edentulous mandible with severe vertical bone deficiency].

OBJECTIVE: To evaluate the applicability, accuracy and clinical outcome of the computer assisted design and computer assisted manufacture (CAD & CAM) tooth-supported implant surgical guide in the mandibular free-end partially edentulous patients with insufficient vertical bone height. METHODS: According to the inclusion criteria, 3 patients (2 women, and 1 man) with the mean age of 45 years (from 44 to 46 years) with 10 implant sites were involved in this study. With the help of Computer-assisted-design software to plan and simulate the surgical strategies, the implant surgical guides were fabricated via the rapid prototyping technique, then the guided implant placement was implemented, finally the post-surgical evaluations were accomplished by the clinical and radiographic examinations. RESULTS: Ten implants were placed in 3 mandibles via the surgical guides, and the implant supported non-split restorations were in place. All the implant restorations revealed good clinical function until the last review. No inferior alveolar nerve injury was detected by the clinical neurosensory test. The immediate post surgical CBCT was performed to confirm a safe distance of 1.5 to 3.0 mm between the implant apical and the nerve canal. The deviations between the planed and the actually placed implant were: coronal deviation (0.84±0.30) mm (0.31-1.24 mm); apical deviation (1.42±0.52) mm (0.52-2.36 mm); angular deviation 7.65°±1.84° (4.43°-9.81°). CONCLUSION: In case of distal free-end partially edentulous with insufficient vertical bone height in the posterior mandibular region, computer assisted surgical design and guided surgery can offer a treatment option with minimal invasiveness and a shorter treatment period, and avoid the complicated bone augmentation procedure and the high risk of nerve transposition. This technique is clinically and technically feasible, but the cases using this technique should be strictly selected according to the indication.

[Implanting the edentulous jaws with "All-on-4" immediate reconstruction: a preliminary clinical observation].

OBJECTIVE: To evaluate the treatment outcome of the "All-on-4" immediate loading protocol via survival rate of the implants,survival rate of the prosthesis,marginal bone, postoperative complications and patient satisfaction. METHODS: In our study, 40 patients with 49 edentulous jaws (31 mandibles and 18 maxillae) were enrolled. Each jaw was restored by the shortened dental arch prosthesis supported by only 4 implants according to the All-on-4 protocol (All-on-4, Nobel Biocare AB, Goteborg, Sweden). For all the patients enrolled in the study, the loading was applied within 12 hours of surgery. The provisional prosthesis could be replaced by the final restorations within 6 to 12 months. In the present study, the survival rate of the both implants and restorations were calculated and analyzed. The radiographic evaluation of marginal bone level changes was measured. The values of the marginal bone level changes of the angled and axial implants were analyzed by the statistic software. RESULTS: In the present study, totally 196 implants were inserted, of which 13 implants failed during the whole following up periods, with 11 implants of the maxillae and 2 of the mandibles. The survival rate of the prosthesis was 95.9% (47/49). The implant survival rate of the maxillae was 85.5% (65/76)while that for the mandibles was 98.3%(118/120). The implant survival rate of the angled implants was 91.8% (90/98), while that for the straight implants was 95.0% (93/98). No significant difference in marginal bone loss was found between angled and axial implants in the 12-month evaluation according to the Wilcoxon rank sum test (P>0.05). During the follow-up period,mechanical complications as fracture of the provisional prostheses, loose of the retain screw, or crack of the artificial teeth were found in 20 prostheses. CONCLUSION: The present preliminary data of the short term observation suggest that the "All-on-4" immediate loading protocol is a viable treatment modality for the edentulous jaws. However, long term clinical random controlled trials with large samples are still needed to confirm the validity of the technique.

Mussel inspired sequential protein delivery based on self-healing injectable nanocomposite hydrogel.

Polysaccharide based self-healing and injectable hydrogels with reversible characteristics have widespread potential in protein drug delivery. However, it is a challenge to design the dynamic hydrogel for sequential release of protein drugs. Herein, we developed a novel mussel inspired sequential protein delivery dynamic polysaccharide hydrogel. The nanocomposite hydrogel can be fabricated through doping polydopamine nanoparticles (PDA NPs) into reversible covalent bond (imine bonds) crosslinked polymer networks of oxidized hyaluronic acid (OHA) and carboxymethyl chitosan (CEC), named PDA NPs@OHA-l-CEC. Besides multiple capabilities (i.e., injection, self-healing, and biodegradability), the nanocomposite hydrogel can achieve sustained and sequential protein delivery of vascular endothelial growth factor (VEGF) and bovine serum albumin (BSA). PDA NPs doped in hydrogel matrix serve dual roles, acting as secondary protein release structures and form dynamic non-covalent interactions (i.e., hydrogen bonds) with polysaccharides. Moreover, by adjusting the oxidation degree of OHA, the hydrogels with different crosslinking density could control overall protein release rate. Analysis of different release kinetic models revealed that Fickian diffusion drove rapid VEGF release, while the slower BSA release followed a Super Case II transport mechanism. The novel biocompatible system achieved sequential release of protein drugs has potentials in multi-stage synergistic drug deliver based on dynamic hydrogel.

Construction of photo-responsive lignin as a broad-spectrum sunscreen agent.

Lignin has potential to serve as promising sunscreen agents as it has good ultraviolet (UV) absorption and antioxidant properties. However, the weak absorption capacity of lignin in the long-wave UV region (UVA, 320-400 nm) limits its further development. In this work, a spiropyran-modified lignin (DLSP) with photo-responsive property was prepared by in-situ construction of spiropyran (SP) structure in the demethylated lignin (DL). Due to the presence of SP moiety, the absorption of DLSP in the UVA region was significantly improved. Under UV irradiation, its absorption peak was redshifted as unconjugated SP form isomerized to conjugated merocyanine (MC) form, and the UVA/UVB ratio increased from 0.62 to 0.74. The free-radical scavenging ability of lignin could protect SP from photodegradation, which provided DLSP excellent fatigue resistance. DLSP were blended into creams to investigate its sunscreen performance. Results indicated that DLSP exhibited radiation-enhanced sunscreen performance, the sun protection factor (SPF) of cream containing 10 wt% of DLSP improved from 20 to 67 after 8 h of UV irradiation. Moreover, DLSP showed low skin penetration and good biocompatibility. These results provide a useful guideline for the rational design of sunscreens with special functionalities.

Combining Bone Collagen Matrix with hUC-MSCs for Application to Alveolar Process Cleft in a Rabbit Model.

BACKGROUND: Most materials used clinically for filling severe bone defects either cannot induce bone re-generation or exhibit low bone conversion, therefore, their therapeutic effects are limited. Human umbilical cord mesenchymal stem cells (hUC-MSCs) exhibit good osteoinduction. However, the mechanism by which combining a heterogeneous bone collagen matrix with hUC-MSCs to repair the bone defects of alveolar process clefts remains unclear. METHODS: A rabbit alveolar process cleft model was established by removing the bone tissue from the left maxillary bone. Forty-eight young Japanese white rabbits (JWRs) were divided into normal, control, material and MSCs groups. An equal volume of a bone collagen matrix alone or combined with hUC-MSCs was implanted in the defect. X-ray, micro-focus computerized tomography (micro-CT), blood analysis, histochemical staining and TUNEL were used to detect the newly formed bone in the defect area at 3 and 6 months after the surgery. RESULTS: The bone formation rate obtained from the skull tissue in MSCs group was significantly higher than that in control group at 3 months (P < 0.01) and 6 months (P < 0.05) after the surgery. The apoptosis rate in the MSCs group was significantly higher at 3 months after the surgery (P < 0.05) and lower at 6 months after the surgery (P < 0.01) than those in the normal group. CONCLUSIONS: Combining bone collagen matrix with hUC-MSCs promoted the new bone regeneration in the rabbit alveolar process cleft model through promoting osteoblasts formations and chondrocyte growth, and inducing type I collagen formation and BMP-2 generation.

Nonsuture anastomosis of arteries and veins using the magnetic pinned-ring device: a histologic and scanning electron microscopic study.

BACKGROUND: The goal of this study was to evaluate the performance of the magnetic pinned-ring device for nonsuture vascular anastomosis. METHODS: The magnetic pinned-ring device consists of paired magnetic rings that are coated with titanium nitride and embedded in a polypropylene shell; the rings are equipped with alternately spaced holes and titanium pins. The vascular anastomosis procedure using the novel magnetic pinned-ring device was performed on 14 mongrel dogs, and the traditional hand-sewing technique was used on 14 additional dogs. In situ end-to-end anastomoses were performed in the femoral artery and the inferior vena cava. Patency was confirmed through ultrasonographic scans at different time points as late as 24 weeks after surgery. Gross observation, histological staining, and scanning electron microscopy were used to evaluate the results at 24 weeks postoperatively. RESULTS: The time required to perform the vascular anastomosis was significantly shorter for the magnetic device than for hand sewing. A continuity of re-endothelialization was confirmed in all anastomotic stomas after 24 weeks, and neither formation of aneurysms nor thickening of the vascular wall was noted. The re-endothelialization was smooth at the anastomotic site of the magnetic device, whereas hand sewing resulted in rough and uneven re-endothelialization and the presence of visible sutures. Moreover, the endothelial cells were regularly arranged at the anastomotic site of the magnetic device, whereas different-sized and irregularly aligned endothelial cells were present at the hand-sewn anastomotic site. Use of the magnetic device was associated with significantly decreased deposition of fibrotic collagen and depressed infiltration of inflammatory cells compared with use of the hand-sewing technique. CONCLUSIONS: The magnetic pinned-ring device offers a simple, fast, reliable, and efficacious technique for nonsuture vascular anastomosis. Use of this device shortens operation time, maintains a high patency rate, and improves the healing of vascular tissue.

[Influence of the placing depth of implants with platform switching on the marginal bone level in the posterior mandible: a clinical study].

OBJECTIVE: The purpose of this study was to evaluate the influence of the placing depth of the implants with platform switching (Ankylos) on the marginal bone remodeling, by means of radiological observation. METHODS: 111 Ankylos implants in the posterior mandible from 46 patients (20 male and 27 female) were enrolled in this study. Followed up by 58.1 months on average (from 36 to 85), 222 mesial and distal sites of these implants were evaluated by means of measuring the level of the marginal bone (LMB) on the panoramic radiograph. RESULTS: Among these 111 successfully functional loaded implants, there were no significant differences with the marginal bone absorption values, no matter the implants were placed below, at, or above the bone level (P>0.05). Concerning the stabilization of the marginal bone, when placed below the bone level, 67.7% of the implant sites had their LMBs stabilized at or above the implant platform, and 23.3% absorbed vertically, respectively 19.7% and 80.3% when placed at the bone level, with significant difference (P<0.001). CONCLUSION: Based on a long-term (over 3 years) observation, the implants placed below, as compared to at or above, the alveolar crest level, might have more chance to keep the marginal bone stabilized at or above the implant platform.

[Implant restoration for patients with congenital missing teeth].

OBJECTIVE: To evaluate the treatment plan, clinical outcome and related problems in patients with congenital missing teeth. METHODS: From November 2000 to February 2009, thirty seven patients with congenital missing teeth underwent thorough diagnostic workup, treatment planning and an interdisciplinary approach to ensure optimal treatment in Department of Implant Dentistry, Peking University, School and Hospital of Stomatology. A standard follow-up protocol was conducted for all the patients. RESULTS: The enrolled cases in this study were classified in to 3 types: single tooth missing, multiple teeth missing and edentulous. Among them single tooth missing was found in 21 cases, multiple teeth missing was found in 12 cases and 4 cases were edentulous. 120 implants were placed and restored in 37 patients with the mean follow-up 39.3 months (10-109 months) after prosthetic functioning. Two implants lost after function about 6 months and the remaining implants functioned well until the last review. No adverse complications such as pain and nerve trauma was observed and the mean bone resorption was 1.91 mm. CONCLUSION: An interdisciplinary approach ensures optimal treatment for patients with congenital missing teeth. Implant restorations provide an alternative way with predictable clinical results.

Paper-Based Enzymatic Colorimetric Assay for Rapid Malathion Detection.

Due to their unique properties, paper-based biosensors have attracted attention as inexpensive devices for on-site analysis. To achieve fast and sensitive detection of analytes, immobilization of enzymes with high apparent activities on paper is highly desirable; however, this is challenging. Herein, we report an improved approach to attach a malathion degrading enzyme, PoOPHM9, on paper via an interlocking network of Pluronic F127 (PF127)-poly(acrylic acid)-enzyme conjugates. The addition of PF127 improved retention of enzymatic activity as the apparent kinetic constant Vmax of the immobilized enzyme increased two-fold compared with the paper prepared without PF127. The PF127-poly(acrylic acid)-PoOPHM9 papers provided rapid colorimetric detection of malathion at 0.1-50 mM. The detection was completed within 5 min using a smartphone and image analysis software. As a proof-of-concept, malathion-contaminated water, plant, and apple samples were analyzed with the papers successfully. This material is promising for on-site rapid analysis of malathion-contaminated samples.

[Clinical study of the application of non-invasive porcelain veneer to improve the aesthetic effects in maxillary anterior area].

OBJECTIVE: To evaluate the clinical results of application of non-invasive porcelain veneer to reduce the black triangle of implant and adjacent teeth and to improve the aesthetic effect in the maxillary anterior area. METHODS: The study included 10 patients (Male: 4, Female: 6; average age: 41.5) accessioned during May 2007 to August 2009 in Peking University School of Stomatology. The provisional restorations were delivery on implant after 3-6 months healing period of the implant. The non-invasive porcelain veneers were used in the round tip adjacent teeth with gingival recession in the indicated patients. Main measured parameters on the model included horizontal distance and vertical distance. The Horizontal distance refers to the black triangle bottom which is from adjacent surface of the natural teeth to the implant restoration at the gingival level. The vertical distance is from mid-point of the triangle bottom to the contact point. Clinical observed items included bleeding index (BI), integrity of porcelain veneer and degree of satisfaction of the patients. RESULTS: A total of 14 adjacent natural teeth in 10 patients were cemented with porcelain veneer. No porcelain veneer was lost or fracture during follow-up period (range 6 to 27 months, mean of 10.4 months). Mean bleeding index 0-1. The horizontal distance was reduced from (3.1 + or - 0.8) mm before restoration to (1.1 + or - 0.5) mm after restoration. Vertical distance from (5.3 + or - 1.1) mm to (2.9 + or - 0.7) mm. All patients were satisfied with the clinical result. CONCLUSION: The data and the experience described in this study indicate that improvement of aesthetic effects by using no-invasive porcelain veneer techniques can be a predictable technique for patients with periodontal disease. Further study is needed to determine the long-term result of the technique.

Comparison of three surgical models of bone tissue defects in cleft palate in rabbits.

OBJECTIVE: Cleft palate is one of the most common craniofacial birth defects in the maxillofacial region. There is an urgent need in tissue regeneration research to establish animal models that faithfully mimic human diseases. Here, we compared three surgical models of bone tissue defects in cleft palate in rabbits in order to screen for the biomaterials that induced optimal bone regeneration. DESIGN: Rabbits were used to establish the models of hard palate cleft, alveolar cleft, and alveolar process cleft. Eight weeks following surgery, bone tissue self-healing capacity was estimated by macroscopic appearance and calculating the area of defective bone tissue. The dimensions of the upper jaw in left and right sides were measured at zero and eight weeks. RESULTS: Bone defects in three types of cleft palate models were made at the positions of the hard palate, alveoli and alveolar process. After 8 weeks, when the hard palate was partially excised, it underwent self-healing. When the hard palate was completely excised, it underwent partial self-healing. However, in the models of alveolar cleft and alveolar process cleft, there was no significant self-healing in the bone tissues. The dimensions of the upper jaw in left and right sides were no significant differences in three types of cleft palate models. CONCLUSIONS: Bone defects in the alveolar and alveolar process clefts exhibit a diminished capability for self-healing. This study may provide valuable information for the screening of materials that induce bone regeneration.

[Clinical study on utilizing free palatal mucosa flap in reconstructing peri-implant attached soft tissue].

OBJECTIVE: To evaluate the results and clinical characteristics of free palatal mucosa flap in reconstructing peri-implant attached soft tissue. METHODS: 126 cases with partial edentulous or edentulous were undergone soft tissue reconstruction and implant treatment from July 1997 to June 2005. A total of 388 implants were placed. The mean follow-up period was over 13 months. Mucosa flaps were measured at the operation and compared the size changes one year after operation. RESULTS: Necrosis occurred in 3 mucosa flaps out of 126 cases 10 days postoperatively. Mean shrinkage of mucosa flap was 56%(37%-70%). No loss of implant was found in the last follow-up and attached soft tissue width was over 3 mm in 371 implants. Eight implants were diagnosed as peri-implantitis (2.06%). CONCLUSION: It is effective and predictable to reconstruct peri-implant attached soft tissue with free palatal mucosa flap.

Minimally Invasive Crestal Sinus Lift Technique and Simultaneous Implant Placement.

OBJECTIVE: To evaluate the effectiveness and clinical results of a new crestal sinus lift technique used to elevate the sinus floor simultaneously with bone grafts and implant placement. METHODS: Eleven patients underwent this crestal sinus lift technique performed using an SCA KIT. The mean residual bone height was 6.4 mm (range: 4.1 mm to 8.6 mm). Bio-Oss collagen was used as the graft material, and 12 implants were simultaneously placed after sinus augmentation. Radiographic and clinical examinations were conducted during follow-up. RESULTS: All procedures were successfully performed with no obvious Schneiderian membrane perforation. The sinus floor was augmented with a mean height of 4.8 mm (range: 2.8 to 7.4 mm). Twelve implants healed uneventfully with healing abutments. Peri-implant marginal bone was stable, with a mean follow-up of 49.4 months (range: 33 to 71 months). No complications were observed during follow-up. CONCLUSION: According to the limited data collected in this study, the novel crestal sinus lift approach could effectively lift the sinus floor and reduce the incidence of postoperative complications. Additional cases with long-term follow-up are needed to confirm and improve this crestal sinus lift technique.

[A minimally invasive extraction technique using Benex Extraction System in flapless immediate implant placement in anterior teeth].

PURPOSE: To evaluate the feasibility and clinical outcomes of an atraumatic extraction technique using Benex Extraction System in flapless immediate implant placement in anterior teeth. METHODS: Twenty-five patients with single hopeless anterior maxillary teeth were enrolled in the study. The involved teeth were extracted using Benex Extraction System and implants were immediately placed in a flapless way. Healing abutments were connected immediately. After 4-6 months of healing, screw-retained implant temporary crowns were used to reshape the peri-implant gingiva. Permanent restorations were delivered 3 months later. Extraction time was recorded and the technique feasibility was evaluated using visual analogue scale (VAS). Peri-implant marginal bone resorption was measured in X- ray films after loading for 1 year later. Pink esthetic score (PES) was checked to evaluate the gingival esthetics. Questionnaire was delivered and collected to assess patients' satisfaction on surgical experience and esthetic outcomes. SPSS 13.0 software package was used for statistical analysis. RESULTS: Twenty-five implants osseointegrated successfully. The marginal bone resorption was (0.21±0.23) mm and PES was 8.8±1.19 after loading for 1 year. The mean extraction time was 6.87 minutes and the VAS was 3.32. All patients were satisfied with the final esthetic outcomes and felt comfort during surgery. CONCLUSIONS: According to the limited data in the study, Benex extraction System is a convenient, atraumatic and predictable technique during flapless immediate implant placement in anterior teeth.

[Three-cuff method for establishing an allogeneic testis transplantation model in the rat].

OBJECTIVE: To establish a model of testis transplantation in the rat using cuff techniques. METHODS: Sixty healthy inbred Wistar rats were included as donors and recipients. The testicular artery with the aortic segment with two cuffs was anastomosed to the recipient's aorta and the testicular vein with a cuff was anastomosed to the left common iliac vein of the recipient. The vas deferens was end-to-end anastomosed. RESULTS: Of the 30 rats undergoing transplantation, 27 survived, 2 died from paralytic intestinal obstruction and 1 died from hemorrhage. Of the 27 survivals, 4, 4 and 5 were vivisected on the 14th, 28th and 56th day after operation, respectively, showing a good blood supply to the graft. Another 14 rats were used in another experiment, which revealed no obvious congestion, necrosis and edema in the left lower limb of the recipients. CONCLUSION: The model of allogeneic rat testis transplantation established with cuff techniques, simple, stable and reliable, can be used as a tool for the study of testis transplantation.

A New Technique for Minimally Invasive Maxillary Lateral Sinus Augmentation: a Case Report.

Numerous techniques are described for lateral sinus augmentation, in order to expand bone volume, either by a crestal or lateral approach. A successful surgical procedure is determined by a number of factors. It is reported that different techniques for sinus augmentation have a high percentage of success, but presents a number of intraoperative and postoperative complications such as the Schneiderian membrane perforation and a long operating time. To manage the problem of the insufficient bone height in the posterior maxilla, various bonegrafting materials were applied using different techniques and instruments to elevate the sinus membrane and fill the subsinus cavity thereafter. The article aimed to describe a minimally invasive technique, using a special design bur to wear out the lateral bone safely and elevate the sinus membrane with sophisticated separators. Platelet-rich fibrin (PRF) and decalcified bone allograft was used as grafting material to enhance bone healing. This new technique for the sinus lateral wall osteotomy minimised the incidence of intraoperative and postoperative complications and the mixed use of PRF with decalcified bone allograft showing a satisficatory efficacy.

[Clinical study of immediate post-extraction implant and immediate function in edentulous patients].

OBJECTIVE: To evaluate the outcomes of immediate post-extraction implant and immediate function according to All-on-4 immediate concept in edentulous patients. METHODS: The study included 46 patients with hopeless teeth. A total of 254 implants were immediately inserted after extraction and 56 fixed complete-arch all-acrylic prostheses finished and functioned on the day of extraction from June 2008 to March 2012 in Peking University School of Stomatology. At time of abutments connection, a panoramic radiograph was taken, and radiographic assessment of the marginal bone level was performed in every 6 months. Marginal bone level, integrity of the restoration, survival of the implants and degree of satisfaction of the patients were evaluated. RESULTS: A total of 254 implants were immediate loading. Thirteen implants were lost 6 - 8 weeks after immediate loading and the survival rate of 94.9% (241/254). The marginal bone absorption was (0.7 ± 0.3) mm on average. All patients were satisfied with the clinical results. CONCLUSIONS: Immediate post-extraction implant and immediate function technique can be a predictable technique. Further study is needed to determine the long-term results of the technology.

[Normal occlusion study: using T-Scan III occlusal analysis system].

OBJECTIVE: To investigate the normal occlusal force distribution and the characteristics of the occlusion time at different occlusion position using T-Scan III occlusal analysis system. METHODS: Fifty-three volunteers with normal occlusion, including 29 males and 24 females, were included in this study. The average age was (25.9 ± 2.1) years old. T-Scan III occlusal analysis system was used to measure the occlusal force distribution and the time character of normal occlusion at intercuspal position, protrusive position, and lateral excursive position. RESULTS: At intercuspal position the left and right side molar teeth took the most part of force percentage, followed by (13.3 ± 4.3)%, (13.6 ± 5.4)%, (15.7 ± 7.1)%, (18.7 ± 7.5)% (6, 6, 7, 7); and 7654, 4567 took (61.3 ± 12.4)% force percentage; and the left and right sides took the respective percentages of (46.4 ± 7.0)%, (53.6 ± 7.0)%, the left side was significantly less than the right side(P < 0.05). At the protrusion position the region ( 21, 12) commitment to take the percentage of (85.1 ± 25.5)%. At left and right lateral position, 28% (13/46) and 30%(14/46) were cuspid-protected occlusion, and 33%(15/46) and 44%(20/46) were group functional occlusion, and 39%(18/46) and 26%(12/46) were multiple-protected occlusion. The average occlusion time was (0.34 ± 0.11) s, and disclusion time was (1.00 ± 0.39) s. CONCLUSIONS: At intercuspal position the region from first premolar to second molar teeth were the occlusal force centers, and the second molar is the most;.the force concentrated in the area ( 21, 12) at the protrusion position. The lateral occlusal pattern is multiformity.