Journal of long-term effects of medical implants最新文献

Dental implants have gained popularity in recent years. The most important variable in determining the effectiveness of the implant's primary stability is bone density. The success of the implant depends on proper procedure and implant stability. With this background, the aim of the present study was to study the correlation between primary stability and bone density. The present retrospective study was conducted among 2,440 patients who had undergone implant treatment in the Department of Implantology, Saveetha Dental College and Hospitals, Chennai, from June 2021 to February 2022. Data regarding patient's age, gender, implant location, bone density, and primary stability were taken into consideration. Association between primary stability and bone density was assessed using the Chi-square test. Of the subjects, 33.42% had D2 bone density in the lower posterior region; 13.98% had D3 density in the lower posterior region. Primary stability of 30-40 Ncm was seen in the majority of the subjects; 32.64% who had primary stability of 30-40 Ncm had D2 bone density. There was a statistically significant association between implant site and bone density (p = 0.04) and primary stability and bone density (p = 0.03). Within the limitations of the study, it can be concluded that there is a strong association between implant primary stability and bone density.

We present the design and stability analysis of an adaptive neuro-fuzzy inference system (ANFIS)-based controller of a pacemaker in MATLAB Simulink. ANFIS uses learning and speed properties of fuzzy and neural networks. Based on body states and preprogrammed situations of patients (age and sex, etc.), heart rate and amplitude of pacing pulse are changed. Output signal that is fed backed from heart is compared to the reference fuzzy bases ANFIS signals. After designing ANFIS based controller, the stability of the proposed system has been tested in both the time (step response) and trequency (Bode diagram and Nichols chart) domains. In our previous study, the step response analyzed and compared with other works. For frequency domain, all the possible frequency analysis methods have been tested but because of nonlinear properties of ANFIS, after linearization, just the Bode diagram achieved good results. The step response results in time domain is compared with previous work's results including optimum heart pulse rate for each particular patient. In the frequency domain, the Bode diagram stability analysis showed gain and phase margin as follows: GM (dB) = 42.1 and PM (deg) = 100.

This virtual study was designed to evaluate the stress-deformation of a metal fixed partial dentures (FPDs) pontic under different loads using two different connectors. The STL file was generated for a RPD of two implant-supported restorations. The Co-Cr metal substructure was designed with two types of connector design. The pontic is connected to implant-supported crowns with square and round shape connectors. This study was designed for a cementless-retained implant-supported FPD. Finite element modeling (FEM) is used to assess the stress and deformation of the pontic within a metal substructure as the FEM might provide virtual values that could have laboratory and clinical relevance. The Co-Cr alloy mechanical properties like the Poisson ratio and modulus of elasticity were based on the parameters of the three-dimensional structure additive method. Nonparametric analyses (Mann-Whitney U test) was used. The use of square or round connectors often resulted in non-significant changes in stress, and deformation under either three or each loaded point on the occlusal surface of a pontic (P > 0.05). However, the deformation revealed distinct variations between loads of the three points compared to each loaded point (P ≤ 0.05). According to this study data, the pontic occlusal surface appears to be the same in stress and deformation under different loads depending on whether square or round connectors are used. While at the same connector designs, the pontic occlusal surface deformed significantly at three loaded points than it did at each point.

An alternative approach to the major problem of osteoarthritis that has begun to pique the interest of researchers focuses on the pathology of the subchondral bone, its constant cross-talk with the articular cartilage, and its interaction with the joint. The presence of bone marrow lesions, detectable on MRI scans, has proven to be a cause of pain as well as a predictor of the progression of degenerative changes. Subchondroplasty is a relatively new surgical procedure for the treatment of these lesions, in which injectable calcium phosphate bone cement is infused into the affected area percutaneously, under fluoroscopic guidance. In its use as a synthetic scaffold, calcium phosphate bone cement exhibits considerable osteoconductivity, bioabsorbability, and low toxicity, thus showing great potential for restoring subchondral biomechanical properties through structural remodeling. Although published results appear quite promising, there are certain complications that the surgeon should be aware of. We reviewed the published data regarding complications of the procedure, highlighting possible causes according to these data, and suggesting safety measures. Avascular necrosis of the talus is the most reported concern. Postsurgical pain, infection, and continuous wound drainage due to bone substitute material extravasation to the joint or soft tissue are also mentioned, necessitating further standardization of the procedure. There are no reports of permanent postoperative disability or fatal outcomes.

Mechanical plaque control is the first line of management of peri-implant diseases. Povidone iodine is one of the broad spectrum and potent antiseptics available at various concentrations. The aim of the study was to assess and compare the efficacy of various concentrations of povidone iodine in the management of peri-implant mucositis. In the present double blinded, parallel designed, randomized clinical trial, a total of 60 patients with peri-implant mucositis (20 participants in each group [Group 1 (povidone iodine 0.1%), Group 2 (povidone iodine 2%) and Group 3 (povidone iodine 010%)] were enrolled. Scaling and root planing was done and then the peri-implant sulcus was irrigated with respective irrigant and repeated once in a week for 4 weeks. Loe and Silness Gingival Index (GI) and Mombelli Modified sulcular bleeding index (BI) were recorded at baseline and after a month and compared. Statistical analysis was done using One-way ANOVA and Tukey's HSD post hoc test. A statistically significant difference (P = 0.000) observed between the three concentrations when compared after 1 month. Also, a statistically significant difference between Group 1 and Group 3 and Group 2 and Group 3 was observed in terms of post GI (P = 0.000) and post BI (P = 0.000) but statistically no significant difference was observed between Group 1 and Group 2 in terms of post GI (P = 0.171) and post BI (P = 0.338). The 2% and 10% povidone iodine showed significant improvement in gingival index and bleeding index and hence it could be an effective adjunct to scaling and root planing in the management of peri-implant mucositis.

Tooth loss is an undesirable condition that leads to functional, esthetic and social damage, having an impact on an individual's quality of life. Dental implants are man-made tooth root replacements that are increasingly used to replace a missing tooth. It is important to gather demographic data in order to take precautions before the possible failures. Hence the objective of this study was to retrospectively determine the association between age, gender, and site of implant placement in patients reporting to a private dental institution. This study was carried out from the data obtained from the case records of 1281 patients who had undergone implant therapy. Chi-square test was applied to see associations of gender, age and implant site. The results show that a maximum number of 348 implants (27.7%) were placed in patients aged between 41-50 years. The patient pool consisted of 705 (55%) females and 576 (45%) males. A maximum of 228 implants (17.80%) were placed in region 46 and 224 implants (17.49%) in region 36. Only 2 implants (0.2%) were placed in region 41. There was a positive association between age, gender and site of implant. In those aged 20-30 years, 20.53% of implants were placed, 26.23% in 31-40 years, 27.1% in 41-50 years, 17.95% in 51-60 years and 8.11% in 61-70 years of age. In male, a maximum of 124 implants (54.4%) were placed in region 46 and only 1 implant (50%) in region 41. In females, region 36 had a maximum of 110 implants (49.1%), and the least number of implants were placed in regions 31 and 41. In this study, it can be concluded that general factors such as age and gender had a significant effect on the site of implant placement.

Obesity is a well-recognized global epidemic that can lead to longer operative times as well as a greater technical demand. Despite this, the available literature evaluating the impact of obesity on hip hemiarthroplasty (HA) and total hip arthroplasty (THA) when treating fractures about the femoral neck is scarce. Between 2015 and 2018, we retrospectively reviewed all patients that had a HA or THA performed as treatment for an isolated fracture of the femoral neck. Patients were classified as obese and nonobese depending on current body mass index (BMI) when the index procedure was performed. Preoperative and postoperative variable were obtained from the electronic medical record. A total of 157 patients underwent hip HA or THA for an isolated fracture of the femoral neck. In those patients undergoing HA, obesity was associated with an increase in operative times (P = 0.021) and was associated with a nonsignificant increase in total operating room time (P = 0.088) and duration of anesthesia (P = 0.14). In those patients undergoing THA, obesity was associated with longer operative times (P = 0.043), total operating room time (P = 0.032), and duration of anesthesia (P = 0.045). There were no significant differences in complication rates postoperatively between obese and non-obese patients undergoing either procedure. The treatment of isolated fractures of the femoral neck with HA or THA leads to an increase in operative time without an increase in postoperative complications in obese patients.

Due to the high rate of rotator cuff re-tear there is an extensive research on augmentation of rotator cuff repairs. The purpose of this single center, prospective study was to evaluate the results of augmentation of the rotator cuff repair with an umbilical cord allograft. The graft group in which the rotator cuff repair was augmented with the graft as an on-lay patch was consisted of 14 patients, while the control group was consisted of 10 patients. The primary outcome of the study was incidence of rotator cuff retears, while secondary outcomes included functional and pain scores. At 6 mo there was a significantly higher incidence of retears in the control group (30%) compared to the graft group (0%; P = 0.028), while at 12 mo the retear rates were statistically similar for the two groups (P = 0.46). The Constant-Murley scores, the ASES scores and the VAS score were similar (P > 0.05) for the two groups at all study times. The results of the study indicated that augmentation of the cuff repair with human umbilical cord graft can result in similar patient reported outcomes compared to a cuff repair without augmentation, but with a lower re-tear rate at 6 mo.

The two presented cases of socket shield technique were done following a split mouth protocol in two patients, each received an immediate implant inserted conventionally on maxillary one side and another implant inserted applying the socket shield technique on the contralateral side. The outcomes including soft and hard tissue changes were compared clinically and radiographically. The four implants were followed for 5 years, and the outcomes were successful.

Persistent pain is one of the most frequent complications following total knee arthroplasty (TKA) and can be devastating for the patient's quality of life. The use of genicular nerve radiofrequency ablation (GNRFA) is prevalent regarding non-surgical treatment of knee osteoarthritis. However, it is controversial when employed for the management of residual pain after TKA. This study aims to evaluate the efficacy of GNRFA for the treatment of post-TKA chronic pain and to assess the potential benefits of its use. Twelve patients sustaining chronic pain after TKA underwent GNRFA treatment. The intervention included the superior medial genicular nerve, the superior lateral genicular nerve and the inferior medial genicular nerve. Visual analog scale (VAS) system was utilized for pain assessment at 1-week, 6-month, and 1-year follow-ups. Patients experiencing chronic knee pain derived from other or unspecified causes were excluded. Mean VAS score before the treatment was 8.3, while it ended up 2.3, 5.7, and 7.9 at the 1-week, 6-month, and 1-year follow-up, respectively. Some patients reported residual pain that they regarded more bearable than before the procedure at the 1-week evaluation, with no significant alterations in the 6-month reassessment. In 2 cases results at the 1-week follow-up were dissatisfying, however, this aided us in distinguishing the cause of the persistent pain. We were not able to conclude that GNRFA used for the treatment of chronic pain after TKA is as efficacious as in knee osteoarthritis pain. However, in some cases, it proved to be beneficial regarding discerning the etiology of the pain.