Occupational protection effect of two protective devices for manual cleaning and oiling of dental handpieces on operators / 中华劳动卫生职业病杂志

Objective: To explore the occupational protective effect of different protective devices on the operators during manual cleaning and oiling of dental handpieces, and to provide a basis for the selection of appropriate protective methods. Methods: From November 2020 to December 2021, 20 high-speed dental handpieces of the same brand were selected and randomly divided into disposable protective bag group and small aerosol safety cabinet group by drawing lots, with 10 in each group. After recording the model, they were distributed to the clinical fixed consulting room for use, and were collected by specially-assigned personnel every day for manual cleaning under the protection of the two devices. By measuring the number of airborne colonies, the concentrations of particulate matter and the satisfaction of operators, the occupational protection effect of the two protective devices on operators was evaluated. Results: Under the protection of the two devices, the average number of airborne colonies after operation was less than 1 CFU/ml. When no protective device was used, the number concentration of particulate matter produced during operation was (21595.70±8164.26) pieces/cm(3). The number concentrations of particles produced by disposable protective bag group [ (6800.24±515.05) pieces/cm(3)] and small aerosol safety cabinet group [ (5797.15±790.50) pieces/cm(3)] were significantly lower than those without any protective device (P<0.001). The number concentration of particle matter of small aerosol safety cabinet group was significantly lower than that of disposable protective bag group (P<0.001). In the satisfaction evaluation of operators, small aerosol safety cabinet group [ (3.53±0.82) points] was significantly better than disposable protective bag group [ (2.23±1.10) points] (P<0.001) . Conclusion: The use of small aerosol safety cabinet during manual cleaning and oiling of dental handpieces has good protective effect, superior safety performance and strong clinical applicability, and has advantages in occupational protection of clinical operators.

Clinical effect evaluation of immediate implant and immediate restoration with socket-shield technique in aesthetic area: a retrospective study with up to 5-year follow-up / 中华口腔医学杂志

Objective: To evaluate the clinical effect of socket-shield technique for 5 years after immediate implantation and immediate restoration in aesthetic area. Methods: The retrospective study was conducted between July, 2013 and July, 2020. A total of 29 patients, with 34 implants, who received immediate implantation and immediate restoration with socket-shield technique in the esthetic zone in Department of Fourth Clinical Division, Peking University School and Hospital of Stomatology were included in this study. The implants survival rate, complications and the pink esthetic score (PES) were evaluated (60.2±26.7) months (13-101 months) after operation. The digital models before treatment and at the final follow-up were obtained, to measure the changes of soft tissue. The labial alveolar bone recession was measured by cone-beam CT. Results: All 34 implants survived during follow-up. The PES was (12.80±1.05), there was no significant difference in PES scores between dental positions (F=1.77, P=0.150). The gingival margin recession was (0.12±0.09) mm, and labial contour change at 2 mm apical to the gingival zenith was (0.45±0.17) mm. The labial alveolar bone recession was (0.14±0.46) mm. Conclusions: Immediate implant with socket-shield technique could maintain the gingival margin and labial alveolar bone, and preserve the soft tissue contour well to achieve good esthetic outcome.

Application evaluation of prefabricated rigid connecting bar in implants immediate impression preparation of edentulous jaw / 北京大学学报(医学版)

OBJECTIVE@#To compare the operation complexity and accuracy of traditional splint impression technique and impression technique with prefabricated rigid connecting bar system for full-arch implants-supported fixed protheses in vitro.@*METHODS@#Standard mandibular edentulous model with six implant analogs was prepared. The implants were placed at the bone level and multiunit abutments screwed into the implants. Two impression techniques were performed: the traditional splint impression technique was used in the control group, and the rigid connecting bar system was used in the test group. In the control group, impression copings were screwed into the multiunit abutments and connected with autopolymerizing acrylic resin. Open tray impression was fabricated with custom tray and polyether. In the test group, cylinders were screwed into the multiunit abutments. Prefabricated rigid bars with suitable length were selected and connected to the cylinders with small amount of autopolymerizing acrylic resin, and open tray impression was obtained. Impression procedures were repeated 6 times in each group. The working time of the two impression methods were recorded and compared. Analogs were screws into the impressions and gypsum casts were poured. The gypsum casts and the standard model were transferred to stereolithography (STL) files with model scanner. Comparative analysis of the STL files of the gypsum casts and the standard model was carried out and the root mean square (RMS) error value of the gypsum casts of the control and test groups compared with the standard model was recorded. The trueness of the two impression techniques was compared.@*RESULTS@#The work time in the test group was significantly lower than that in the control group and the difference was statistically significant [(984.5±63.3) s vs. (1 478.3±156.2) s, P < 0.05]. Compared with the standard model, the RMS error value of the implant abutments in the test group was (16.9±5.5) μm. The RMS value in the control group was (20.2±8.0) μm. The difference between the two groups was not significant (P>0.05).@*CONCLUSION@#The prefabricated rigid connecting bar can save the chair-side work time in implants immediate loading of edentulous jaw and simplify the impression process. The impression accuracy is not significantly different from the traditional impression technology. The impression technique with prefabricated rigid connecting bar system is worthy of clinical application.

Clinical classification and treatment decision of implant fracture / 北京大学学报(医学版)

OBJECTIVE@#To propose a set of two-dimensional clinical classification of fractured implants based on the follow-up of fracturing pattern of implant body and peri-implant bone defect morphology of 32 fractrued implants, and summarize the treatment decisions of fractured implants according to this new set of classification, so as to provide guidance for clinical practice.@*METHODS@#During 25 years of clinical practice, clinical records of 27 patients of 32 fractured implants in 5 481 patients with 10 642 implants were made. The fracturing pattern of implant body, implant design, peri-implant bone defect morphology and treatment options were analyzed. A set of two-dimensional clinical classification based on the morphology and bone absorption of implant fracture was proposed. The treatment decision-making scheme based on the new classification of implant fracture was discussed.@*RESULTS@#In the new classification system, vertical fracture of implant neck (Type 1 of implant fracture morphology, F1) and horizontal fracture of implant neck (Type 2 of implant fracture morphology, F2) were common, accounting for 50% and 40.6% respectively, while deep horizontal fracture of implant body (Type 3 of implant fracture morphology, F3) (9.4%) were rare, while the three types of bone defects (D1, no bone defect or narrow infrabony defects; D2, wide 4-wall bone defects or cup-like defects, D3, wide 3-wall or 2-wall defects) around implants were evenly distributed. In the two-dimensional classification system of implant fracture, F1D1 (31.3%) and F2D2 (25%) were the most frequent. There was a significant positive correlation between F1 and D1 (r=0.592, P < 0.001), a significant positive correlation between F2 and D2 (r=0.352, P=0.048), and a significant negative correlation between F1 and D2 (r=-0.465, P=0.007). The most common treatment for implant fracture was implant removal + guided bone regeneration(GBR) + delayed implant (65.6%), followed by implant removal + simultaneous implant (18.8%). F1D1 type was significantly related to the treatment strategy of implant removal + simultaneous implantation (r=0.367, P=0.039). On this basis, the decision tree of implant fracture treatment was summarized.@*CONCLUSION@#The new two-dimensional classification of implant fracture is suitable for clinical application, and can provide guidance and reference for clinical treatment of implant fracture.

Effect of Porphyromonas gingivalis infection on atherosclerosis in apolipoprotein-E knockout mice / 北京大学学报(医学版)

OBJECTIVE@#Studies have indicated that periodontal pathogen Porphyromonas gingivalis (P. gingivalis) infection may contributed to accelerate the development of atherosclerosis. The aim of this study was to investigate the effect of inflammation, oxidative stress and the mechanism on atherosclerosis in apolipoprotein-E knockout (ApoE-/-) mice with P. gingivalis infection.@*METHODS@#Eight-week-old male ApoE-/- mice (C57BL/6) were maintained under specific pathogen-free conditions and fed regular chow and sterile water after 1 weeks of housing. The animals were randomly divided into two groups: (a) ApoE-/- + PBS (n=8); (b) ApoE-/- + P.gingivalis strain FDC381 (n=8). Both of the groups received intravenous injections 3 times per week for 4 weeks since 8 weeks of age. The sham control group received injections with phosphate buffered saline only, while the P. gingivalis-challenged group with P.gingivalis strain FDC381at the same time. After 4 weeks, oxidative stress mediators and inflammation cytokines were analyzed by oil red O in heart, Enzyme linked immunosorbent assay (ELISA) in serum, quantitative real-time PCR and Western blot in aorta.@*RESULTS@#In our study, we found accelerated development of atherosclerosis and plaque formation in aorta with oil red O staining, increased oxidative stress markers [8-hydroxy-2-deoxyguanosine (8-OHdG), NADPH oxidase (NOX)-2 and NOX-4], as well as increased inflammation cytokines [interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α)] in the serum and aorta of the P. gingivalis-infected ApoE-/- mice. Compared with the control group, there was a significant increase protein level of nuclear factor-kappa B (NF-κB) in aorta after P. gingivalis infection.@*CONCLUSIONS@#Our results suggest that chronic intravenous infection of P. gingivalis in ApoE-/- mice could accelerate the development of atherosclerosis by disturbing the lipid profile and inducing oxidative stress and inflammation. The NF-κB signaling pathway might play a potential role in the P. gingivalis-accelerated atherogenesis.

Clinical study of immediate post-extraction implant and immediate function in edentulous patients / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the outcomes of immediate post-extraction implant and immediate function according to All-on-4 immediate concept in edentulous patients.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>

Clinical study of prosthetic gingival reconstruction in vertical bone defect patients / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the preliminary clinical results of prosthetic gingival reconstruction in vertical bone defect patients.</p><p><b>METHODS</b>The study included 31 partial or edentulous patients (male 22, female 9) with 152 implants supporting fixed prostheses from February 2002 to January 2011 in Peking University School and Hospital of Stomatology. The implant-supported fixed prostheses with artificial gingival material to compensate for vertical defect were delivery after implant healing period. At time of prostheses delivery, a panoramic radiograph was taken. The results were evaluated according to California Dental Association by two prosthodontists. Clinical observation included survival of the implants, integrity of the restoration, complication of prosthesis and degree of satisfaction of the patients.</p><p><b>RESULTS</b>A total of 152 implants supported fixed prostheses with artificial gingival materials to compensate vertical bone defect were delivered. No implants lost, and the survival rate was 100% during the follow-up period. The sore of acceptance of prosthesis was 96.8%. All patients were satisfied with the clinical results.</p><p><b>CONCLUSIONS</b>The artificial gingival reconstruction technique is feasible for vertical bone defect patients.</p>

Clinical study of "All-on-4" implant immediate function in edentulous patients / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the preliminary clinical results of application of All-on-4 immediate function in edentulous patients.</p><p><b>METHODS</b>Twenty nine edentulous patients with 140 immediately loaded implants supporting fixed complete-arch all-acrylic prostheses from April 2008 to October 2009 in Peking University School of Stomatology were included. The implant-supported fixed complete-arch all-acrylic prostheses were delivery on the operation day. At time of abutments connection, a panoramic radiograph was taken. And radiographic assessment of the marginal bone level was performed in every 2 months. Clinical observe items included marginal bone level, integrity of the restoration, survival of the implants and degree of satisfaction of the patients.</p><p><b>RESULTS</b>A total of 140 implants were immediate loading. Eight implants were lost during 6 - 8 weeks after immediate loading, giving survival rate of 94.3%. The marginal bone level was (0.8 ± 0.4) mm. The All patients were satisfied with the clinical results.</p><p><b>CONCLUSIONS</b>The data and the experience described in this study indicate that All-on-four immediate function technique can be a predictable technique for edentulous patients. Further study is needed to determine the long-term result of the technology.</p>

A long-term retrospective clinical study of short dental implant restoration / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the long-term results of short implants and assess its clinical importance.</p><p><b>METHODS</b>A total of 77 short implants were consecutively placed in 43 patients from August 1998 to August 2004. The clinical data was reviewed and the crown-implant ratio (C/I) was measured. Twenty-nine short implants in 15 patients were loaded for more than 5 years and the marginal bone height around implant measured. The implant success and survival ratio were evaluzted according to Zarb's successful criteria and Wheeler's survival criteria.</p><p><b>RESULTS</b>The mean follow-up time was 5.4 years (36 ∼ 99 months). Among these 77 short implants, 74 implants were fixed restoration, which mean C/I was (1.08 ± 0.21), 3 implants were removable restoration. Of 29 short implants which were loaded for more than 5 years, the mesial bone height at the times immediately after inserting implant, before second stage surgery, loading for less than 3 years and loading for more than 5 years was (0.59 ± 0.66), (0.64 ± 0.59), (-0.05 ± 1.11), (-0.37 ± 1.29) mm; and the distal bone height was (0.62 ± 0.77), (0.60 ± 0.86), (-0.26 ± 1.12), (-0.23 ± 1.59) mm. The 5 year's survival rate and success rate were 97% and 93% respectively.</p><p><b>CONCLUSIONS</b>The success and survival rate of short dental implant under function were comparable to those reported for normal implants. By using the short implant, the patients can avoid the graft operation, alleviate sufferings, shorten the treatment period and reduce the cost. Therefore, it has a high value in clinical application.</p>

An animal study of peripheral neurophysiologic mechanism in osseoperception phenomena of dental implant / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the existence of functional neuroreceptors in peri-implant bone tissue and to test the peri-implant neural feedback pathway reconstruction and its influential factors.</p><p><b>METHODS</b>Three beagle dogs were involved in this study. After the extraction of 3 premolars and 1 molar of the bilateral mandible, 27 implants were placed immediately or delayed. The implants were loaded for 3 - 6 months, then sensory nerve action potential (SNAP) tests were performed. The stimulating electrode was connected to the implant or natural tooth. The recording electrode was fixed near the inferior alveolar nerve (IAN) to record the latency period and amplitude of SNAP. The specimens with peri-implant bone tissues were taken and examined by immunohistochemistry.</p><p><b>RESULTS</b>SNAP of IAN could be recorded following stimulations to natural teeth and implants. The differences in SNAP amplitudes between natural teeth [(44.04 +/- 6.23) microV] and all implant groups were statistically significant (P < 0.01). Free nerve endings and nerve tract were found in the peri-implant bone tissue, but much less than those in periodontal membrane. Some nerve fibers were directly connected with implant surface.</p><p><b>CONCLUSIONS</b>Functional neuroreceptors, though much less than that of natural tooth, exist in peri-implant bone tissue. Surgical methods and loading time do not have obvious influences on peri-implant neural feedback pathway reconstruction.</p>

Clinical study of tissue preservation of extraction socket with Bio-Oss collagen and acellular dermal matrix / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical and histological results of extraction socket preservation using Bio-Oss collagen and acellular dermal matrix (ADM).</p><p><b>METHODS</b>From November 2005 to June 2006, a total of 11 cases underwent extraction socket preservation with Bio-Oss collagen and ADM in 14 extraction sites. Ten cases with 10 teeth undergoing extraction without bone graft served as control group. Clinical and histological examinations were conducted. Pre-and postoperative alveolar ridge width and attached gingival width were measured and statistically analyzed.</p><p><b>RESULTS</b>All the grafted sockets healed uneventfully except one. Thirteen implants were placed 3 - 5 months after extraction. After 4 to 6 months permanent restorations were delivered. The mean follow-up time was 27.9 months (24 to 31 months). In the control group the sockets healed uneventfully, while hard and soft tissue collapsed obviously 3 months after extraction. No significant difference was found in the width of alveolar ridge and attached gingiva before and after extraction in the bone graft group (P > 0.05). The width of alveolar ridge before (7.69 + or - 0.48) mm and after extraction (7.68 + or - 0.48) mm and in the width of attached gingiva before (4.36 + or - 1.02) mm and after extraction (4.32 + or - 0.98) mm in the bone graft group (P > 0.05). Histological examination showed adequate new bone formation around Bio-Oss particles 3 months after operation. The specimen was free of inflammatory cells.</p><p><b>CONCLUSIONS</b>It's effective to preserve the extraction sockets with Bio-Oss collagen and ADM and the short-term results were predictable.</p>

A clinical study on orthodontic treatment after tooth autotransplantation / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the pulp vitality, the periodontal condition and the success rate of autotransplanted teeth after orthodontic treatment.</p><p><b>METHODS</b>A total of 20 permanent teeth (one of them had been treated by root canal therapy), 17 with completely developed roots and 3 with developing roots, were autotransplanted to the region of missing teeth in 16 admitted patients. Orthodontic treatment was carried out in all cases. Clinical and radiographic evaluation of the transplanted teeth was done.</p><p><b>RESULTS</b>The average time of postoperative orthodontic treatment was 1.9 months. In all, one autotransplanted tooth was lost because of periodontal disease during follow-up. Eight autotransplanted ones had positive electric pulp testing (EPT) response. Fifteen out of 20 autotransplanted teeth were surrounded by newly-formed periodontal space with normal size and lamina dura. The numbers of surviving and successful autotransplanted teeth were 19 and 15, respectively, after an average observation period of 24.5 months.</p><p><b>CONCLUSIONS</b>Orthodontic treatment of autotransplanted teeth was acceptable and the pulp vitality of the teeth might be preserved.</p>

Clinical study of application of platform switching to dental implant treatment in esthetic zone / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical results of dental implant treatment with platform switching technique in esthetic zone and to investigate its technical characteristics.</p><p><b>METHODS</b>Seventeen patients who were partially edentulous in esthetic zone were included and received a total of 26 Frialit-2 system implants in Center of Dental Implantation, Peking University School and Hospital of Stomatology from January to December 2001, and the platform switching technique was applied. The mean follow-up time was 56.3 months (24 to 74 months). Clinical examination and X-ray were conducted.</p><p><b>RESULTS</b>Clinical results of all implant restoration that used platform-switched abutments were satisfied. No implant loss or other severe complications occurred. The medians of marginal bone loss 1 year and 5 years after final restoration was 0.13 (-0.12 - 0.55) mm and 0.27 (-0.04 - 0.77) mm respectively. The medians of interimplant crestal bone resorption was 0.14 (0.00 - 0.30) mm and 0.21 (0.09 - 0.31) mm after 1 year and 5 years' functional loading respectively. According to Jemt classification of papilla, 23 sites reached II degree, and 10 sites reached III degree among 36 sites 5 years after prostheses. The mean value of pink esthetic score (PES) was 11.8 (10 - 14).</p><p><b>CONCLUSIONS</b>Platform switching is a simple and reliable technique for dental implant treatment, helping to control marginal bone loss and ensure an esthetic results in the esthetic zone.</p>

Mini-plate implant anchorage for maxillary protraction in Class III malocclusion / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects using mini-plate implant as anchorage for maxillary protraction in skeletal Class III malocclusion with retruded maxilla.</p><p><b>METHODS</b>Totally 8 skeletal Class III patients aged 11 - 14 years were included in this study. There were 4 males and 4 females. The mini-plate implants were placed between the upper lateral incisors and canines on both sides in each patient. The mask was used after 1 month healing following mini-plate implant surgery. Cephalography and panoramic radiographs were taken for each patient before and after protraction. Twenty-one cephalometric measurements were used for assessment. Statistically, paired t-test was used.</p><p><b>RESULTS</b>After protraction, SNA, ANB, Wits, NA-PA, Max-Lth, A-NP distances increased and the significant difference was founded (P < 0.01). ANS-Me, Is-FHp, Ms-FHp, A-FHp distances increased significantly, too (P < 0.05). L1-AP, OJ, AB-NP decreased and the significant difference was detected (P < 0.05). The changes of SNB, MP-SN, PP-SN, U1-PP, U1-SN, U1-AP, L1-MP and ANS-Me/N-Me ratio were not significant (P > 0.05).</p><p><b>CONCLUSIONS</b>Mini-plate implant was an effective and stable anchorage for promoting forward growth of maxilla following maxillary protraction.</p>

Minimally invasive extraction and immediate implant placement with single-stage surgical procedure: a clinical observation of 21 cases / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical results of minimally invasive extraction without flap reflection and immediate implant placement with single-stage surgical procedure.</p><p><b>METHODS</b>Twenty-one patients (23 single-tooth implants) were included in the study. Eight fractured teeth and 15 residual roots in the maxillary anterior region were extracted without flap reflection and implants placed immediately. Special gingival former was connected at the same time of implant placement with single-stage surgical procedure, final prostheses were restored after 6 months. The follow-up time was from 13 months to 51 months (mean: 27.6 months) after final restoration. Clinical and radiographic study were conducted, the interproximal papillae were analyzed according to Jemt's classification and the level of soft-tissue margin and buccal soft tissue color were evaluated according to Fürhauser's method.</p><p><b>RESULTS</b>All 23 implants acquired osseointegration, and the level of marginal bone at the mesial and distal aspects of all implants were stable. The mesial and distal papilla index score of 3 were observed in 18 implant sites, the papilla index score of 2 in 5 implant sites. Harmonious relationship of gingival margin between peri-implant restorations and adjacent natural teeth was observed in 15 implant sites. The color of buccal soft tissue matched that of the adjacent natural teeth in 18 implant sites, 5 sites showed minor discrepancies. All the patients were satisfied with the final restoration.</p><p><b>CONCLUSIONS</b>Minimally invasive extraction without flap reflection and immediate implant placement with single-stage surgical procedure is a sensitive technique. Many factors may affect the final results and the strict control of indication is the key factor.</p>

Clinical study of implant-retained facial prosthesis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate clinical results and technical characteristics of implant-retained facial prosthesis.</p><p><b>METHODS</b>Six patients with facial defects underwent implant retained prosthesis treatment, of which 3 orbita defects (including upper and lower eyelids, eyeball) in 3 cases, 2 ears defects in 2 cases, and a nose defect in one case. Under local anaesthesia 21 extra-oral implant were placed, facial prosthesis were individually made six month postoperatively. Follow up ranged from 6 month to 6 years.</p><p><b>RESULTS</b>All 21 implants osseointegrated well, implant lost and peri implantitis was not found. All 6 cases had individual facial prosthesis and were satisfied with the prosthesis.</p><p><b>CONCLUSIONS</b>Extra oral implants provided excellent retainment for facial prosthesis; result of current silicon with individual color shade is encouragable.</p>

A clinical retrospective study of 10 years implant results / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate ten years clinical results of dental implant treatment.</p><p><b>METHODS</b>A total of 5,590 endosseous implants were consecutively placed from Aug. 1994 to Aug 2004 in Center of Implantation, Peking University School and Hospital of Stomatology. Among them, 161 were Brånemark implants, 1,436 were Frialit-2 implants, 1,012 were IMZ implants, 767 were Ankylos implants, 2,189 were Camlog implants, and 25 were Komet implants. A total of 2,629 prostheses were delivered, including 2,314 fixed prostheses and 315 implant-supported removable dentures. The patient age range was between 17 and 82. The mean follow-up time was 77.2 months (7 to 121 months). Clinical examination and X-ray films were conducted. The results were evaluated with Wheeler's survival criteria.</p><p><b>RESULTS</b>With the final prostheses, 2,624 patients were satisfied. Five patients were unsatisfied with the prostheses. With refabricating the prostheses, 4 patients were satisfied and one expressed as acceptable. Peri-implantitis was observed in 178 implants of 105 cases. Prostheses loose was observed in 21 cases and fracture in 4 cases. Ceramic crack was observed in 51 cases. The documented implants lost were 68. The implant survival rate was 96.7% according to Wheeler's survival criteria.</p><p><b>CONCLUSIONS</b>Implant prostheses were with high satisfaction. The implant survival rate was as highly as 96.7%. Implant prostheses were indicated for almost all the partial and complete edentulous cases due to modern implant surgical technique.</p>

Evaluation of clinical results on osteotome sinus floor elevation and dental implant placement (122 cases report) / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical results of osteotome sinus floor elevation technique in the posterior maxillary region.</p><p><b>METHODS</b>A total of 122 patients underwent osteotome sinus floor elevation from July 1998 to July 2004. Forty-eight cases were male and 74 were female. The mean age was 46.5 years (between 20 and 69). A total of 157 implants were placed and restored. The mean follow-up time was 29.7 months (between 14 and 84 months). Clinical examination and radiographs were conducted. All the patients with 8 - 11 mm height of residual bone in the posterior maxilla underwent sinus floor elevation and implant placement using osteotome without any bone grafts simultaneously. The elevation height was 2 - 5 mm. Healing abutments were connected at the same time of implant placement with insertion torque over 0.25 N.m and the final prostheses were restored after 3 - 4 months. Implants were submerged if the insertion torque was less than 0.25 N.m. Second-stage operation was conducted 3 - 4 months later and the implants were restored afterwards.</p><p><b>RESULTS</b>Sinus membrane perforation was observed in 12 cases, no sinus complication was observed during the follow-up. All of the 157 implants gained osteointegration and were restored. No implant lost was observed during the follow-up. All the patients were satisfied with the final prostheses.</p><p><b>CONCLUSIONS</b>Osteotome sinus floor elevation without any bone graft was a predictable and safe technique. It could be used in the maxillary posterior area implant placement with residual bone volume of 8 - 11 mm.</p>

Clinical application of implant supported magnet-retained overdenture / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical effects of implants supported magnet-retained overdenture.</p><p><b>METHODS</b>From November 1999 to March 2005, 25 cases with edentulous jaws underwent implant-supported magnet-retained overdenture. Among them, 14 patients were male, 11 patients were female. The average age of the patients was 67.6 years. (Range 45 - 79 years). Ninety-five implants used included Komet (18), IMZ (11), Frialit-2 (12), Ankylos (10), Camlog (44). The fellow-up time was from 6 months to 70 months. Clinical examination and radiographs were conducted.</p><p><b>RESULTS</b>No infections, nerve or sinus damage or other sequelae occurred. The overdentures were stable and functioned effectively. From November 1999 to March 2005, One Komet abutment was fracture and 1 Frialit-2 implant was lost because of overloading during follow-up. The remaining implants achieved successful osseointegration. Patients were satisfied with the treatment.</p><p><b>CONCLUSIONS</b>Implant-supported magnet-retained overdenture was a predictable and reliable method, especially for old patients with edentulous jaws.</p>

Preliminary clinical study of microimplants in the restoration of edentulous jaws / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate if magnetic- attached overdenture supported by microimplants of 2.5 mm in diameter was able to function properly.</p><p><b>METHODS</b>Fourteen microimplants were placed in 4 patients. Implants were exposed 3 months later and magnetic abutments were connected directly. X-ray was taken during the 3 year follow-up to examine marginal bone level. Peri-implant soft tissue was also checked. Denture retention, chewing stability and overall satisfaction with the microimplants retained overdenture were evaluated.</p><p><b>RESULTS</b>All of the 14 microimplants achieved initial primary stability without infection or any other postoperative complications. No implant was lost during the follow-up period. Only one magnetic abutment fractured one year after restoration and was replaced. X-ray showed highly stable marginal bone level around the microimplants. The patients were satisfied with the restoration.</p><p><b>CONCLUSIONS</b>The microimplants retained overdenture leads to a significant improvement of function despite of the small dimensions of these implants. In particular for elder patients with severe residual ridge resorption, this treatment represents a less invasive alternative compared to conventional implant systems.</p>