Objective:To investigate the effects of repeated high acceleration(+Gz)on implant osseointegration in SD rats.Methods:18 SD rats were divided into+Gz and control groups randomly(n=9),and 1 implant was placed in each femur of the rat's lower limb.24 hours postoperatively,the experimental rats were exposed to+Gz of 4 to 9 G with 1 G/s environment 3 times a week,while the con-trol rats were fed normally.3 rats from each of the 2 groups were sacrificed at 2,4 and 8 weeks after implantation.Micro-CT,sequential fluorescence double labeling,and histological examination were perfomed for the analysis of implant osseointegration.Results:The bone volume fraction(BV/TV),trabecular number(Tb.N),mineral apposition rate(MAR),implant-bone contact rate(BIC)and bone area in implant thread(BA)of the+Gz group were significantly lower than those of the control group at 2 weeks(P＜0.05),and so as to MAR,BA at 4 weeks(P＜0.05),while there was no significant difference of the parameters at 8 weeks after implantation.Conclusion:In SD rats early exposure to+Gz environment postoperatively may have a negative effect on initial osseointegration by slowing bone forma-tion.However,it will not lead to poorer bone mass when sustained over a long period.

Objective:To study the effects of metformin on marginal bone resorption of implants in patients with type 2 diabetes melli-tus(T2DM)and exercise habit.Methods:63 cases with 73 implants were included.Among them,there were 41 cases(47 implants)without T2DM in group N,10 cases(13 implants)with T2DM and without exercise habit in group M,12 cases(12 implants)with T2DM and exercise habit in the MR group.The patients were followed up at 6 months,1 and 2 years after implantation.The marginal bone loss(MBL).Implantation success rate and peri-implantitis incidence rate were compared among the groups.Results:The bone resorption of the proximal and median margins of the long-term bone level of the implants in the N and MR groups were significantly lower than that in the M group(P=0.001 and P=0.000 5,respectively).The implant success rates of group N,MR and M were 95.74％,100％and 76.92％,respectively.The incidence of peri-implantitis of the three groups was 2.13％,0 and 15.38％,respec-tively.Conclusion:Metformin is more effective in the improvement of the long-term marginal bone resorption of implants,increase the success rate of implants,and reduce the incidence of peri-implantitis in patients with T2DM and exercise habit in the mandibular first molar area.

Alveolar bone is an important anatomic basis for implant-supported denture restoration, and its different degrees of defects determine the choices of bone augmentation surgeries. Therefore, the reconstruction of alveolar bone defects is an important technology in the clinical practice of implant restoration. However, the final reconstructive effect of bone quality, bone quantity and bone morphology is affected by many factors. Clinicians need to master the standardized diagnosis and treatment principles and methods to improve the treatment effect and achieve the goal of both aesthetic and functional reconstruction of both jaws. Based on the current clinical experience of domestic experts and the relevant academic guidelines of foreign counterparts, this expert consensus systematically and comprehensively summarized the augmentation strategies of alveolar bone defects from two aspects: the classification of alveolar bone defects and the appropriate selection of bone augmentation surgeries. The following consensus are reached: alveolar bone defects can be divided into five types (Ⅰ-0, Ⅰ-Ⅰ, Ⅱ-0, Ⅱ-Ⅰ and Ⅱ-Ⅱ) according to the relationship between alveolar bone defects and the expected position of dental implants. A typeⅠ-0 bone defect is a bone defect on one side of the alveolar bone that does not exceed 50% of the expected implant length, and there is no obvious defect on the other side; guided bone regeneration with simultaneous implant implantation is preferred. Type Ⅰ-Ⅰ bone defects refer to bone defects on both sides of alveolar bone those do not exceed 50% of the expected implant length; the first choice is autologous bone block onlay grafting for bone increments with staged implant placement or transcrestal sinus floor elevation with simultaneous implant implantation. Type Ⅱ-0 bone defects show that the bone defect on one side of alveolar bone exceeds 50% of the expected implant length, and there’s no obvious defect on the other side; autologous bone block onlay grafting (thickness ≤ 4 mm) or alveolar ridge splitting (thickness > 4 mm) is preferred for bone augmentation with staged implant placement. Type Ⅱ-Ⅰ bone defects indicate that the bone plate defect on one side exceeds 50% of the expected implant length and the bone defect on the other side does not exceed 50% of the expected implant length; autologous bone block onlay grafting or tenting techniques is preferred for bone increments with staged implant implantation. Type Ⅱ-Ⅱ bone defects are bone plates on both sides of alveolar bone those exceed 50% of the expected implant length; guided bone regeneration with rigid mesh or maxillary sinus floor elevation or cortical autologous bone tenting is preferred for bone increments with staged implant implantation. This consensus will provide clinical physicians with appropriate augmentation strategies for alveolar bone defects.

Patients with type 2 diabetes mellitus (T2DM) have a large demand for dental implants, but the pathologic state of T2DM patients could compromise the efficacy of implant treatment. Glycemic control can improve the success rate of implants in the T2DM population, but the early osseointegration of individuals still needs to be improved. Strengthening early osseointegration in patients with T2DM is one of the urgent problems for clinicians. The pharmacological mechanisms of hypoglycemic drugs on the market for bone metabolism are different and may require different interventions on the bone around the implant, but there is a lack of direct clinical evidence of the protective effect of hypoglycemic drugs. This review integrated the bone metabolic effect of drugs in clinical medical research and dental implant research. The aim was to provide medication guidance for T2DM patients who require implant surgery, and it is recommended to avoid the use of drugs with negative effects on bone as far as possible without violating the clinical medication guidelines, including SGLT-2 inhibitors and thiazolidinediones. Instead, they should choose glucose-lowering drugs that are beneficial to bone metabolism, such as insulin, metformin and GLP-1 receptor agonists. However, the comparative clinical effects of these drugs on periimplant bone need to be further elucidated. The researcher should select appropriate drugs (incretin drugs) to enhance the early osseointegration of implants in patients with T2DM.

Diabetes mellitus is a relative contraindication of dental implant therapy, that limits the application of implant therapy severely. Diabetic status often leads to secondary vascular and bone lesions, which affect treatment adversely and lead to an increased failure rate. Therefore, how to implement implant therapy for diabetic patients has become a difficult question for dentists. According to the research and experience over the years on diabetic patients, and referring to the current research progress on this topic, the authors will discuss the clinical characteristics of diabetic patients and the details of treatment process, for reference.

Objective:To investigate the effect of guided bone regeneration (GBR) on marginal bone loss (MBL) in the region of the mandibular posterior tooth by using a retrospective cohort study, in order to provide reference for clinical practice.Methods:The research subjects were patients who received dental implants from October 2008 to June 2011 in the region of the mandibular posterior tooth at the Department of Oral Implantology, School of Stomatology, The Fourth Military Medical University. According to whether GBR was performed or not and the time of implant insertion, the patients were divided into the controls group (patients without bone grafting), simultaneous GBR implantation group, and delayed GBR implantation group. On this basis, the MBL was measured according to radiographs by comparing the marginal bone level from that of immediate postoperation 10 years ago. General data was collected and compared among groups, including modified plaque index (mPI), modified sulcus bleeding index (mSBI), probing depth (PD), and gingival papilla height.Results:The controls group (patients without bone grafting), implantation group, and delayed GBR implantation group followed 58, 76, 26 implants in 26, 32, 13 patients aging at (46.5±9.9), (45.5±10.7), (58.3±6.4) respectively. The duration of the follow-up was (11.2±0.7), (11.1±0.8), (11.1±0.9) years respectively. The 10-year implant survival rate was 100% (58/58), 100% (76/76), 100% (26/26). The MBL was (0.91±0.28), (0.84±0.27), (1.01±0.27) mm respectively. The MBL difference of patients with simultaneous GBR implantation and delayed GBR implantation showed statistical significance ( P<0.05), but these two groups showed no statistical significance compared with the controls group ( P>0.05). The mPI, mSBI, PD, and gingival papilla height of the three groups all had no significance on statistics ( P>0.05). Conclusions:It can be concluded that there is no difference in long-term marginal bone resorption between simultaneous and delayed implantation with or without GBR (using autologous blood mixed with granular bone meal) in the posterior mandibular area.

Through a review of the literature on surface treatment of superhydrophilic implants and its clinical application, this paper discusses the shortening of load time, the improvement of the planting success rate and its long-term effect. Additionally, attention should be paid to the nonindication of superhydrophilic implants and issues requiring attention. The literature review showed that healthy patients could carry out an early load 21 days after implantation of superhydrophilic implants, and the load could be completed as soon as 6 weeks after implantation with superhydrophilic short implants when the residual alveolar bone height of the posterior dental area was repaired. Even if the residual alveolar bone density of the patient is low, the application of superhydrophilic implants can shorten the healing period to 8 weeks. Notably, some studies have reported that superhydrophilic implants have no significant effect on patients with a history of radiotherapy and the use of anticoagulants. Because the adhesion of the superhydrophilic implant to the bacteria is also improved to some extent, it is very important to prevent the use of antibiotics when using the superhydrophilic implant. Finally, this paper discusses and anticipates the future research direction of superhydrophilic implants: longer periodic follow-up and more in-depth molecular mechanism studies.

With the development of dental implant prosthodontic technique, many new concepts and methods have emerged. In the light of present situation, implant prosthodontic technique is developing towards precision, comfortability, immediacy and digitization. Meanwhile, the research area is focusing on expanding immediate restoration indications, clinical selection strategies of different prosthodontic materials and the accuracy of digitalized prosthodontics. The paper aims to discuss the developing trend in prosthodontics of dental implantology for clinical reference.

In 2017, there were 451 million people (ages 18 to 99) with diabetes worldwide, and this number is expected to grow to 592 million by 2035. A series of complications in diabetic patients often leads to oral vascular and bone lesions. Therefore, dental implant doctors urgently need to understand the clinical characteristics of diabetes mellitus patients to provide the best treatment. For dental implant doctors, the following problems still exist in the treatment of diabetic patients with poor blood sugar control: ① alveolar fossa healing in diabetic patients is slow after extraction, and bone regeneration is often needed, which prolongs the treatment cycle and increases the pain of patients; ② the rate of new bone formation in diabetic patients after alveolar bone grafting is slow; ③ it takes a long time for the body to achieve effective bone bonding after dental implantation in diabetic patients, and the outcomes are poor; ④ the health of the tissue around dental implants is affected by blood sugar level, which is difficult to maintain in diabetic patients. Current studies suggest that the long-term success rate of implants is predictable in diabetic patients when blood sugar levels are well controlled (HbA1c < 6%). This article will review the current research status of dental implantation therapy for diabetic patients to provide a reference for clinical practice.

OBJECTIVETo compare the difference of the diameters of superior mesenteric vein (SMV) and gastrocolic trunk (GCT) between patients with cecum-ascending colon cancer and normal individuals, and to assess the diagnostic value of the diameters of SMV and GCT in cecum-ascending colon cancer.

METHODSPreoperative imaging data of 60 patients with primary cecum-ascending colon cancer confirmed by postoperative pathology at the First Affiliated Hospital of Sun Yat-sen University from June 2014 to December 2016 were retrospectively analyzed. The diameters of SMV and GCT were measured on preoperative CT images. SMV was measured at about 2 cm below the junction of SMV and splenic vein. GCT was measured at 1 cm near the proximal junction of right colon vein, right gastroepiploic vein and anterior pancreaticoduodenal vein. Another 60 people receiving pelvic CT examination without organ illness were collected as control. The diameter differences of SMV and GCT between cancer group and control group were compared. The diagnostic value of the diameters of SMV and GCT in cecum-ascending colon cancer was evaluated by receiver operating characteristic (ROC) curves.

RESULTSAmong 60 cases of cecum-ascending colon cancer, 36 were males and 24 were females with median age of 48 years (range 28-84); 13 were cecum cancer, 47 were ascending colon cancer; 11 had no lymph node and liver metastasis, 40 had lymph node metastasis, 9 had liver metastasis (all with lymph node metastasis). Compared to control group, the diameters of SMV and GCT in cancer group were significantly longer [SMV:(11.2±1.3) mm vs. (9.5±1.7) mm, t=6.04, P<0.001; GCT:(5.5±0.9) mm vs. (3.5±1.0) mm, t=11.51, P<0.001]. However, there were no statistically significant differences in diameters of SMV and GCT among hepatic metastasis, lymph node metastasis and no metastasis cancer groups (all P>0.05). The ROC curve analysis showed that the area under the curve of SMV diameter was 0.777, and the optimal cut-off point was 10.5 mm in the diagnosis of cecum-ascending colon cancer, with the sensitivity and specificity of 95.0%(57/60) and 46.7%(28/60) respectively. The area under the curve of GCT diameter was 0.923, and the optimal cut-off point was 4.5 mm in the diagnosis of cecum-ascending colon cancer, with sensitivity and specificity of 88.3%(53/60) and 85.0%(51/60) respectively.

CONCLUSIONThe dilation of the SMV and GCT may be used as warning factors for cecum-ascending colon cancer, especially the diameter of GCT.

Adult ; Aged ; Aged, 80 and over ; Cecum ; Colon, Ascending ; pathology ; Colonic Neoplasms ; pathology ; Female ; Humans ; Male ; Mesenteric Veins ; anatomy & histology ; Middle Aged ; Retrospective Studies