A retrospective evaluation of a treatment protocol for dental implant periapical lesions: long-term results of 39 implant apicoectomies

PURPOSE: The goal of this study was to evaluate retrospectively the efficacy of a treatment modality for a lesion at the apical portion of a nonmobile dental implant. MATERIALS AND METHODS: All patients were treated with an intraoral treatment approach. A flap was elevated facial to the effected implant site, exposing the bone. A carbide bur was used to open a window in the bone. The bur was then used to cut the implant and completely remove the affected portion of the implant. The surgical site was then closed with interrupted vicryl sutures, and patients were prescribed. RESULTS: Thirty-nine implants in 35 patients with a mean age of 58.3 years were identified clinically and radiographically with the presence of a periapical lesion. These 39 implants, which constituted 9.9% of implants (39 of 395) placed in these 35 patients, were consecutively treated using the intraoral apicoectomy procedure. Thirty-eight of the 39 implants (97.4%) treated with this technique remained stable and continued in function with no further complication. Follow-up time averaged 4.54 years; the longest follow-up time exceeded 15 years. CONCLUSION: Based upon the results of this retrospective study, lesions in the apical region of implants can be treated successfully using an intraoral apicoectomy procedure.     

即刻种植的临床探讨

目的：报告拔牙后即刻种植的临床结果并对即刻种植的处理方法进行探讨。方法：拔除患牙，清创拔牙窝后，采用Branemark种植系统的操作方法，在Ⅰ期手术，将Branemark种植体即刻植入患者颌骨，酌情植入自体骨或异体骨，必要时加盖生物膜；4～6个月后，进行Ⅱ期手术，再经1～2周后，用目定修复体修复。结果：138颗即刻种植的Branemark种植体中，上颌76颗，下颌62颗，有4颗种植体失败，观察最长60个月，最短36个月，种植体存留率为96．4％。结论：即刻种植初步临床结果是满意的，其长期效果有待进一步的观察。     

Preliminary evaluation of a new dental implant design in canine models

Problems with crestal bone resorption and bone adaptation to dental implants in compromised and weak bone present clinical challenges due to insufficient bone volume. Mathematical models have shown that a new, square-thread, dental implant design increases functional surface area and reduces shear loading at the implant interface. The aim of this investigation was to evaluate the ability of bone to grow between the threads of the new implant and its general biocompatibility in a canine model. Test implants were placed in the mandibles of four beagle dogs after posterior partial edentulism. Three months after implantation, the animals received independent fixed partial dentures, were followed for an additional 6 months, and then euthanized for histological analyses. Analyses revealed that bone grew between the threads and closely apposed the new implant design. Histological observations also revealed that the inferior aspect of the test implant threads were apposed by more bone than the coronal aspect, suggesting a biological advantage for the compressive load transfer mechanism of the new implant design. The results of this study revealed that the new implant design became osseointegrated with bone growing between the threads of the device.     

A novel dental implant abutment with micro-motion capability—Development and biomechanical evaluations

Objective

The aim of this study was to develop a novel dental implant abutment with a micro-motion mechanism that imitates the biomechanical behavior of the periodontal ligament, with the goal of increasing the long-term survival rate of dental implants.

Methods

Computer-aided design software was used to design a novel dental implant abutment with an internal resilient component with a micro-motion capability. The feasibility of the novel system was investigated via finite element analysis. Then, a prototype of the novel dental implant abutment was fabricated, and the mechanical behavior was evaluated.

Results

The results of the mechanical tests and finite element analysis confirmed that the novel dental implant abutment possessed the anticipated micro-motion capability. Furthermore, the nonlinear force–displacement behavior apparent in this micro-motion mechanism imitated the movement of a human tooth. The slope of the force–displacement curve of the novel abutment was approximately 38.5 N/mm before the 0.02-mm displacement and approximately 430 N/mm after the 0.03-mm displacement.

Significance

The novel dental implant abutment with a micro-motion mechanism actually imitated the biomechanical behavior of a natural tooth and provided resilient function, sealing, a non-separation mechanism, and ease-of-use.     

Critical evaluation of patient responses to dental implant therapy

Statement of problem. Successful rehabilitation of the edentulous condition requires functional and psychosocial adaptation by the patient. Quality of life is markedly affected by the amount of satisfaction or dissatisfaction with their dental therapy. Patient concerns are primarily related to comfort, function, and esthetics. When these do not meet the patients expectations, anxiety, insecurity, diminished self-esteem, and introversion are typical psychosocial responses.Purpose. The objectives of the study were to assess the patient's subjective feelings about: (a) comfort, (b) function, (c) esthetics, (d) speech, (e) self-image, and (f) overall dental health with their existing complete dentures, and after implant therapy and prosthodontic rehabilitation. Material and methods. Two health-related quality of life (HRQL) questionnaires were developed to evaluate the effectiveness of dental implant therapy; one dealing with their feelings about their conventional complete dentures, and the second dealing with implant therapy. The first questionnaire was administered with supervision before receiving implant treatment. The second questionnaire was administered within 1 year after completion of prosthetic rehabilitation. Twenty-six patients who received implants to support a mandibular prosthesis and a new maxillary denture formed the experimental population. Results. Discriminative and evaluative analysis of subjective patient responses provided reliable, accurate, and reproducible results. Assessment of subject feelings before and after implant therapy and prosthodontic rehabilitation demonstrated significant differences when before treatment responses were compared with the responses after therapy. Conclusions. Significant differences for comfort, function, speech, esthetics, self-image, and dental health were demonstrated when conventional complete dentures and dental implant therapy were compared. HRQL data provided scientific evidence of an improved quality of life after dental implant therapy (p < 0.000). (J Prosthet Dent 1997;78:574)     

A novel computational method for real-time preoperative assessment of primary dental implant stability

A novel methodology which allows for fast and fully automatic structural analysis during preoperative planning for dental implant surgery is presented. This method integrates a fully automatic fast finite element solver within the framework of new concepts in computer-assisted preoperative planning for implant surgery. The planning system including optimized structural planning was validated by experimental results. Nine implants were placed in pig mandibles and mechanically loaded using a testing rig. The resulting displacements were measured and compared with those predicted by numerical analysis during planning. The results show that there were no statistically significant differences (P = 0.65) between the results of the models and the experiments. The results show that fast structural analysis can be integrated with surgical planning software allowing the initial axial implant stability to be predicted in real time during planning. It is believed that such a system could be used to select patients for immediate implant loading and, when further developed, be useful in other areas of preoperative surgical planning.     

A novel bioactive glass/graphene oxide composite coating for a polyether ether ketone-based dental implant

Polyether ether ketone (PEEK) is a biocompatible material that lacks antimicrobial activity and bioactivity; therefore, is not appropriate for use as a dental implant. To overcome these deficiencies, a novel composite coating of bioactive glass and graphene oxide was prepared. PEEK discs were polished, cleaned, and the surface treated with sulfuric acid for 15 min. The composite coating consisted of bioactive glass produced by the sol-gel route and doped with 0.75 wt% graphene oxide. X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy-energy dispersive spectroscopy analyses were employed to characterize the composite coating, and the coating adhesion strength quantified using a pull-off test. Cytotoxicity was assessed using osteoblast-like cells and gingival fibroblasts. The wettability of the coated and non-coated samples was determined by optical contact angle assessment, and bioactivity was assessed by immersion in simulated body fluid. The results revealed that the bioactive glass/graphene oxide composite coating, approximately 7 μm thick, was transparent, homogenous with few microcracks and microporosities, but adhered strongly and was not cytotoxic to either osteoblast-like cells or gingival fibroblasts. The wettability of the PEEK sample was increased to <20° after coating with the composite, and apatite formation was detectable after 14 days of immersion in simulated body fluid.     

Choice of a dental implant system

Many dentists are bewildered by the intricacies and complexities of dental implants. They are constantly besieged by product advertisements and can find it difficult to choose which systems to work with. Some dentists are so intimidated by the subject that they choose to avoid getting involved with implants and instead stick to traditional tooth replacement systems. By breaking implants down into 4 main components, the body, collar, connection, and restorative post, it is easier to understand the structure and function of dental implants. Each portion should be designed to achieve certain objectives. Once these structural components are understood, it is easier to compare and contrast differing implant systems.     

A holder for dental implant screwdrives

This article describes an easy procedure for making a holder for the small, short screwdrivers used to tighten and loosen implant superstructures. It can aid significantly during manipulation of the intraoral attachments.     

Clinical evaluation of a novel dental whitening lamp and light-catalyzed peroxide gel

OBJECTIVE: This study examined whether an ultraviolet light enhanced the whitening efficacy of a peroxide gel containing a photo-Fenton activator. METHODOLOGY: Fifty subjects were enrolled into the trial at two geographically separate sites. As directed by the randomization keys, teeth of half of the study subjects were concurrently exposed to the whitening lamp, while the gel was on their teeth, for a total light exposure of 45 minutes. The other half of the subjects received no light treatment. At each examination, clinical data were collected on the gingival index, shade score, and self-assessed dentinal hypersensitivity. RESULTS: Changes in tooth shade were significantly better (approximately 26% improvement; p < 0.05) for subjects exposed to the gel and dental whitening lamp (average = 7.7 shade changes) compared to subjects exposed to the gel only (average 6.1 shades) immediately after treatment. No reports of erythema, desquamation, ulceration of soft tissues, gross changes in teeth, gingiva, or restorations were documented. The relative changes in mean sensitivity scores were similar for both groups, with no significant differences between the Light and No-light groups at any interval. CONCLUSION: The whitening effect was improved by approximately 26% when the Zoom2 dental whitening lamp was used. It was demonstrated that the a photo-Fenton activator used with a bleaching light and 20% hydrogen peroxide gel is safe and effective for whitening teeth rapidly.     

种植体联合牙半切术单冠修复下颌磨牙的疗效观察

目的探讨应用种植体联合牙半切术单冠修复下颌磨牙的临床疗效。方法选择12例患牙,健康牙根完善根管治疗,微创拔除病变牙根。半切术后8～10周植入种植体,种植体植入后3～4个月进行种植二期手术,安装穿牙龈愈合基台。牙龈愈合4～6周后开始进行全冠修复,并随访2～4年。结果 11例种植体联合牙半切术单冠修复下颌磨牙均获成功,种植体稳固,种植体周骨组织未见明显吸收,修复体形态美观,功能恢复良好,患者满意度高。1例因病变的远中牙根与牙槽骨发生骨粘连,术中不得不使用骨凿损伤了近中牙根而一并拔除。结论种植体联合牙半切术单冠修复下颌磨牙是一种有效的修复方法。