无牙颌种植覆盖义齿修复设计与并发症

传统全口义齿有稳定性差、固位不良、咀嚼效率低等缺点，难以被患者接受。与传统全口义齿相比，无牙颌种植覆盖义齿由种植体提供支持或辅助固位，可获得较好的稳固性和患者满意度，得以在临床广泛应用。然而，无牙颌种植覆盖义齿组成结构和修复设计复杂，受患者自身颌骨条件、修复空间和口腔卫生维护能力等因素的影响，在使用过程中易发生并发症。文章就无牙颌种植覆盖义齿修复设计中种植体数量、位置和附着体类型的选择及并发症做一阐述。     

无牙颌种植覆盖义齿修复设计与并发症

 传统全口义齿有稳定性差、固位不良、咀嚼效率低等缺点，难以被患者接受。与传统全口义齿相比，无牙颌种植覆盖义齿由种植体提供支持或辅助固位，可获得较好的稳固性和患者满意度，得以在临床广泛应用。然而，无牙颌种植覆盖义齿组成结构和修复设计复杂，受患者自身颌骨条件、修复空间和口腔卫生维护能力等因素的影响，在使用过程中易发生并发症。文章就无牙颌种植覆盖义齿修复设计中种植体数量、位置和附着体类型的选择及并发症做一阐述。     

Patient evaluation of treatment with fixed implant- supported partial dentures

The aim of this study was to analyse the patient evaluation of functional treatment outcome in 40 periodontally compromised patients who received implant-supported prostheses (ISPs) as part of the total treatment. The treatment protocol comprised periodontal treatment, extraction of teeth with poor prognosis, placement of dental titanium implants, and after healing, insertion of fixed ISPs. Five of the patients became edentulous in one jaw after extraction of all teeth and received a complete ISP, whereas 35 patients became partially edentulous after extraction of some teeth, 12 receiving a partial ISP on > or = 3 implants, and 23 one on two implants. The follow-up period was on average 1.8 years after the connection of the prostheses, which provided the patients a dentition with a mean of 12 occluding dental units. The first author (S.-W. Yi) performed all implant treatment. Patients' opinions on oral functions--mastication, phonetics, oral hygiene, chewing comfort and aesthetics--were evaluated by means of a questionnaire both before implant installation and at the last follow-up. A control group of 30 subjects with a healthy dentition of 14 occluding natural pairs of teeth answered the same questionnaire on one occasion. A great majority of the patients were extremely satisfied with the oral function after treatment and experienced the ISPs as 'natural teeth'. There was no significant difference between the three treatment groups and the control group for mastication, phonetics, chewing comfort and aesthetics. Patients with ISPs reported a small but significantly greater difficulty with oral hygiene procedures than the controls with natural teeth. Most patients said that they would undergo the treatment again, if necessary, and recommend it to others. It was concluded that the rehabilitation of the periodontally compromised patients, including ISPs on osseointegrated dental titanium implants, resulted in subjectively improved and satisfactory oral function.     

Implant survival in periodontally compromised patients

BACKGROUND: Relatively little is known on the long-term prognosis of implants inserted in partially edentulous, periodontally compromised patients. METHODS: A total of 258 conventional implants, 57 two-stage and 201 one-stage implants, which were inserted in 32 and 108 patients, respectively, between June 1988 and June 2002 were followed with respect to their survival, as well as the periodontal parameters bone loss, probing depth, and bleeding on probing. All patients were periodontally compromised who had undergone periodontal surgery and were considered able to maintain a high standard of oral hygiene. RESULTS: The 5-year survival rates were 97% and 94%, respectively, for the two- and the one-stage implants. The 10-year survival rate remained high at 97% for the two-stage implants, but had dropped to 78% for the one-stage implants. Smoking, short implant length, and insertion during the later period (1995-2002) were found to be associated with an increased failure rate. CONCLUSIONS: Implants placed in patients with a history of periodontitis have a 5-year survival similar to that observed for implants installed in non-diseased persons. Although the 10-year survival of the one-stage implants was somewhat lower than has been observed for non-diseased patients, implant placement remains a good treatment alternative also for periodontally compromised patients.     

Peri-implantitis in partially edentulous patients: association with inadequate plaque control

Objective: The aim of the present study was to describe some clinical periodontal features of partially edentulous patients referred for the treatment of peri‐implantitis. Material and methods: The 23 subjects involved in this study were selected from consecutive patients referred to the department of Periodontology Södra Älvsborgs Hospital, Borås, Sweden, for treatment of peri‐implantitis during 2006. The patients had clinical signs of peri‐implantitis around one or more dental implants (i.e.≥6 mm pockets, bleeding on pockets and/or pus and radiographic images of bone loss to≥3 threads of the implants) and remaining teeth in the same and/or opposite jaw. The following clinical variables were recorded: Plaque Index (PI), Gingival Bleeding Index (GBI) Probing Pocket Depth (PPD), Access/capability to oral hygiene at implant site (yes/no), Function Time. The patients were categorized in the following sub‐groups: Periodontitis/No periodontitis, Bone loss/No bone loss at teeth, Smoker/Non‐smokers. Results: Out of the 23 patients, the majority (13) had minimal bone loss at teeth and no current periodontitis; 5 had bone loss at teeth exceeding 1/3 of the length of the root but not current periodontitis and only 5 had current periodontitis. Six patients were smokers (i.e. smoking more than 10 cig/day). The site level analysis showed that only 17 (6%) of the 281 teeth present had ≥1 pocket of ≥6mm, compared to 58 (53%) of the total 109 implants (28 ITI^® and 81 Brånemark^®); 74% of the implants had no accessibility to proper oral hygiene. High proportion of implants with diagnosis of peri‐implantitis were associated with no accessibility/capability for appropriate oral hygiene measures, while accessibility/capability was rarely associated with peri‐implantitis. Indeed 48% of the implants presenting peri‐implantitis were those with no accessibility/capability for proper oral hygiene (65% positive predict value) with respect to 4% of the implants with accessibility/capability (82% negative predict value). Conclusion: The results of the study indicate that local factors such as accessibility for oral hygiene at the implant sites seems to be related to the presence or absence of peri‐implantitis. Peri‐implantitis was a frequent finding in subjects having signs of minimal loss of supporting bone around the remaining natural dentition and no signs of presence of periodontitis (i.e. presence of periodontal pockets of ≥6 mm at natural teeth). Only 6 of the examinated subjects were smokers. In view of these results we should like to stress the importance of giving proper oral hygiene instructions to the patients who are rehabilitated with dental implant and of proper prosthetic constructions that allow accessibility for oral hygiene around implants.     

Comparative analysis of immediate functional loading and immediate nonfunctional loading to traditional healing periods: a 5-year follow-up of 550 dental implants

Background: Clinical, radiographical, and histological findings have shown that immediately loaded implants show the presence of mineralized tissues at the interface.
Purpose: The aim of this study was to compare an immediate loading protocol with a two-staged one using an implant with a square thread design.
Materials and Methods: One hundred fifty-five consecutive patients (71 men, 84 women), aged between 18 and 78 years (mean: 54 years) participated in this study. A total of 550 implants (Maestro; BioHorizons, Birmingham, AL, USA) were inserted. In group A, 264 implants were inserted in 82 patients with immediate functional loading with occlusal contact if the patients were completely edentulous, or with immediate nonfunctional loading without occlusal contact if the patients were partially edentulous. In group B, 286 implants were inserted in 73 patients with a one-stage or two-stage surgical procedure. All patients were followed for at least 5 years.
Results: In the immediately loaded implants group, three implants failed, all in posterior mandibular sites, with an overall 98.8% 5-year survival rate. In the control group, no implant failed, with a 100% 5-year survival rate. No statistically significant differences were found in the survival rates of the implants in the two groups.
Discussion: A very high implant survival rate was also present in our series for the immediately loaded implants. All the three failed implants were retrieved from the same patient, who had poor oral hygiene, after a loading period of 5 years. These data can suggest that, from a clinical point of view, an abbreviated healing period is compatible with the development and maintenance over a longer time period (5 years) of mineralized tissues at the interface with dental implants.
Conclusion: We can then conclude that shorter healing periods can be highly satisfactory from a clinical point of view.     

A prospective 15‐year follow‐up study of mandibular fixed prostheses supported by osseointegrated implants. Clinical results and marginal bone loss.

In this prospective study 47 edentulous patients were treated with mandibular fixed prostheses supported by osseointegrated Brånemark implants and followed for 12 to 15 years. Three 1%) of the 273 inserted implants were lost, two before and one six years after placement of the fixed prosthesis. The cumulative success rate CSR) of the implants was 98.9% both after 10 and 15 years. None of the fixed prostheses was lost and at the last follow‐up, all patients had stable fixed prostheses in function (CSR 100%). The marginal bone loss around the implants was small, on average 0.5mm during the first post surgical year and thereafter about 0.05mm annually. More bone was lost around the anterior implants than around the most posterior ones. Smoking and poor oral hygiene had significant influence on bone loss, while occlusal loading factors such as maximal bite force, tooth clenching and length of cantilevers were of minor importance. It is concluded that the long‐term results of the mandibular implant treatment were extremely successful, regarding both the fixed prostheses and implant stability. Bone resorption around the implants, albeit limited, was influenced by several factors, smoking and oral hygiene appeared to be most important.     

Long-term dental implant success and survival--a clinical study after an observation period up to 6 years

The aim of the present work was to evaluate the long-term results of dental implants and the risk factors associated with implant survival and success rates. 108 patients were examined and the control consisted of medical history taking, clinical and radiographic examinations. The survival rate of dental implants was 96.0% and the success rate was 94.3%. Mucositis was found to be related to patients' age and the number of implant units placed. Peri-implantitis was often found in patients showing low standards of oral hygiene as well as in those who were not coming on regular dental visits. Mucositis was in every 5th implant site and was mostly seen in patients with prosthetic constructions consisting of 3 or more units as well as in older patients. Oral hygiene and dental control visits are important to maintain good oral health.     

Immediate transmucosal implants using the principle of guided tissue regeneration. (II). A cross‐sectional study comparing the clinical outcome 1 year after immediate to standard implant placement.

The aim of the present study was to compare the peri‐implant mucosal conditions 1 year after immediate transmucosal implant placement without or in combination with guided tissue regeneration with the situation after regular placement of transmucosal 1‐stage procedure implants in partially edentulous patients. The test group consisted of 15 patients who required the immediate replacement of 20 teeth with oral implants in combination with guided tissue regeneration. The control group 1 consisted of 6 patients who received 8 immediate implants, without concomitant bone regeneration procedure due to the small size of the extracted roots in comparison to the diameter of the implants. The 20 patients of the control group 2 were randomly chosen from over 150 partially edentulous patients who received implants of the ITI® Dental Implant System according to the standard procedure. Similar favorable clinical parameters were found around the implants of all the 3 groups with low plaque and mucosal indices, similar amounts of recession, pocket probing depths and clinical attachment levels. The immediate implants demonstrated lower frequencies of sites bleeding on probing. The study has established that immediate oral implants are a feasible treatment modality with high predictability.     

Choosing or refusing oral implants: a prospective study of edentulous volunteers for a clinical trial

PURPOSE: Little is known about why people accept or refuse oral implant treatment. The purpose of this study was to assess edentulous subjects' acceptance or refusal of free implants to retain mandibular dentures, and to evaluate factors that might predict those who are more likely to choose implants. MATERIALS AND METHODS: One hundred one volunteers completed questionnaires about their background, satisfaction with conventional dentures, oral health-related quality of life, and preference for implants. Results were analyzed using Pearson chi-square tests and logistic regression. RESULTS: While 79% of volunteers accepted and 21% refused an initial offer of free implants, a number of them changed their minds, leaving 64% who wanted implants and 36% who did not want them. The most common reason for choosing implants was anticipation of improved mandibular denture stability or security (73%), while the most common reason for refusal was concern about surgical risks (43%). A logistic regression model identifying those who complained of poor chewing function, poor speech, pain, and dissatisfaction with appearance improved the prediction of those who wanted implants from 64% to 80%. CONCLUSION: When cost was removed as a factor, more than one third (36%) of the older, edentulous participants in this study ultimately refused an offer of free implants to retain their mandibular dentures. Poor chewing function, poor speech, pain, and dissatisfaction with appearance were the most important factors in predicting who would choose implants.     

A Comparison between Endodontics and Implantology: An 8‐Year Retrospective Study

Purpose: The aim of this study was to compare endodontic and implant treatments and to evaluate their predictability over an 8‐year period on the basis of an analysis of survival data and a retrospective clinical study. Materials and Methods: A group of 40 partially edentulous patients were selected for this study. Their teeth had been endodontically treated and rehabilitated using gold alloy and ceramic restorations. In these patients, 65 osseointegrated implants were restored with single gold alloy–ceramic crowns and monitored on a yearly basis for 8 years with standardized periapical radiographs, using a polivynilsiloxane occlusal key as a positioner. A total of nine patients who did not attend the yearly follow‐up were excluded from the study. The Melloning and Triplett criteria were used to evaluate the clinical results obtained in the implant sites. The clinical results of the 56 endodontically treated teeth, restored with the fixed prosthesis of 40 patients, were analyzed according to probing depth as well as an assessment of the correct apical and coronal seals. The survival rate was calculated using the Kaplan–Meier method and the statistical significance was calculated using the chi‐square test. Results: During the follow‐up of the endodontically treated elements, seven failures were detected (83.34%) and the success rate of implants inserted in the same patients was equal to 80.8%, with nine implants lost in 8 years. The survival analysis of the elements treated with both therapies was not statistically significant (p = .757) and the confidence interval was between 0.2455 and 2.777. Conclusion: In view of the superimposable results between the two therapies, it should be noted that the endodontically treated teeth could be interested by different pathologies while the restoration of the atrophic edentulous ridge with an implant support is predictable when patients comply with correct oral hygiene and when the occlusal loads are axially distributed in implant‐protected occlusion.     

微创种植固定修复在下颌无牙颌患者中的临床应用研究

目的：通过在下颌微创种植8枚种植体，使下颌无牙颌患者获得固定义齿。方法：对下颌无牙颌要求种植固定义齿的患者进行筛选，制定详细的治疗方案。采用不翻瓣的手术方法植入8枚种植体，对患者原义齿缓冲后做过渡使用。术后6个月采用黏固式分段烤瓷桥的设计方式修复完成至少12牙单位修复。结果：本院自2006年至2013年期间采用此方法对下颌无牙颌患者完成种植固定义齿修复18例，追踪期（0.8-7年）内，种植体存留率100%，种植体周围组织稳定，义齿局部崩瓷一例。结论：下颌无牙颌患者8枚种植体支持的固定义齿咀嚼功能恢复理想，患者使用舒适方便，义齿卫生易于维护，患者接受度和满意度高。     

Interforaminal implant placement in oral cancer patients: during ablative surgery or delayed? A 5-year retrospective study

In a retrospective study, two mandibular prosthetic rehabilitation strategies supported by implants in oral cancer patients were evaluated: implants placed in the non-resected edentulous symphyseal area during ablative surgery (DAS implants); or at a later stage (postponed (P) implants). Medical files of patients from two head-neck oncology groups from 2000 to 2005 were screened for study inclusion. DAS protocol was used in one group and P protocol in the other. After a 5 year follow-up of 261 edentulous patients with oral cancer in the second group, P implants were placed in 27 patients to support an overdenture. Of the 249 edentulous patients in the first group, 82 patients were given an implant supported overdenture using the DAS implant protocol. Regarding implant loss, no statistically significant differences were seen between the DAS and P implants. In the DAS group, more patients benefited from an implant-supported lower overdenture (39 versus 11%, respectively), and they received their overdenture on average 20.0 months sooner (sd = 11.01, p < 0.001) after ablative surgery. 17.1% of DAS implants and 4.6% of P implants were never loaded due to tumour and patient related factors including unfavourable implant soft tissue, tumour recurrence near the implant, or radiotherapy induced trismus.     

The adaptation of implant-supported superstructures to the alveolar crest: a follow-up of 49 cases

A prospective clinical and radiographic study has been carried out in 49 patients with a total of 252 implants. In a mixture of 17 edentulous mandibles, 20 edentulous maxillas, nine partial edentulous cases, and three single-tooth cases, prosthetic treatments were aimed at getting as close an adaptation as possible between gingival tissues and superstructure. The shortest possible abutments were used, and the implants were surgically positioned subcrestally. The results during a 5-year follow-up showed a success rate of 98.9% for fixtures in the lower jaw and 96.3% for the upper jaw with a total success rate of 97.3%. The marginal bone reduction during five years with closely adapted superstructures was 0.11 mm in the mandible and 1.1 mm in the maxilla. Our results support the use of close gingivally adapted superstructures, although oral hygiene controls and instructions are regularly advisable.     

Slant-Lock Implant-Supported Overdenture

Slant-Lock overdentures, Class I: Division 3 prostheses, provide a stable and retentive prosthetic design for edentulous patients with osseointegrated implants. In patients who have moderate to severe atrophy of the edentulous ridge, the Slant-Lock overdenture provides additional support for the para-oral structures. The prostheses increase the ease of oral hygiene for the edentulous patient, can be constructed using conventional prosthodontic techniques, and are reasonably economical.     

Simultaneous Le Fort I osteotomy and zygomatic implant placement

The aim of this retrospective study was to evaluate the outcomes of simultaneous LeFort I osteotomy and zygomatic/dental implant placement for oral rehabilitation of patients with extremely atrophic/dysmorphic edentulous maxilla.Simultaneous LeFort I osteotomy and zygomatic/dental implant placement was performed with patient-specific anatomical models and surgical guides produced through three-dimensional virtual planning methods. All patients received their final prosthesis, with immediate loading, on the day after surgery. The primary outcome variables were the implant survival rate, and the incidence of intra/postoperative complications. In total, 15 zygomatic implants and 33 conventional dental implants were inserted in eight patients. The mean follow-up of the patients was 38.5 months. The implant survival rate was 93.3% for zygomatic implants and 100% for dental implants. No intra/postoperative complications were observed.Simultaneous LeFort I osteotomy associated with zygomatic/dental implant surgery can be considered as a valuable treatment option for rehabilitation of patients with extremely atrophic edentulous maxilla and esthetic issues of the face.     

The effectiveness of 2‐implant overdentures – a pragmatic international multicentre study

Summary The purpose of this multicentre observational study was to determine patient satisfaction with either conventional dentures or mandibular 2‐implant overdentures in a ‘real world’ setting. Two hundred and three edentulous patients (mean age 68·8 ± 10·4 years) were recruited at eight centres located in North America, South America and Europe. The patients were provided with new mandibular conventional dentures or implant overdentures supported by two implants and ball attachments. At baseline and at 6 months post‐treatment, they rated their satisfaction with their mandibular prostheses on 100‐mm visual analogue scale questionnaires. One hundred and two (50·2%) participants had valid baseline and 6‐month satisfaction data. Although both groups reported improvements, the implant overdenture group reported significantly higher ratings of overall satisfaction, comfort, stability, ability to speak and ability to chew. These results suggest that edentulous patients who choose mandibular implant overdentures have significantly greater improvements in satisfaction, despite their relatively higher cost, than those who choose new conventional dentures.     

Prospective review of integral implants.

There are several factors that strongly correlate to HA-coated implant success and the prevention of implant morbidity. Surgical placement must be performed without compromise in technique. Implants placed into thin ridges or those that had dehiscence of their surface did not uniformly gain bone attachment levels during the healing period. Countersinking implants in extraction sites was critical; labial bone implant defects should be grafted with particulate HA. HA grafts to labial bone defects at the time of implant placement surgery are still short-term. Primary closure of all implant surgical sites prevented epithelial invagination into the surgical site and is associated with improved bone height around implants. Premature exposure of the implant during the healing period is associated with crestal bone loss. Loading forces should be physiologic, with maintenance of a physiologic equilibrium by a balanced restoration. Bone bulk should be created or preserved. Bone around implants may adversely respond to excessive loading forces. In the posterior maxilla, crestal bone loss has been observed that seems to result from excessive cantilever-type forces placed on the implants or from when implants are placed in the posterior mandible developed progressive bone loss that was associated with several factors. These factors included articulation against a natural occlusion, a horizontal ridge contour level with the external oblique ridge, a nonhygienic restoration, and the lack of keratinized gingiva against the abutment. Whether titanium implants develop progressive bone loss in the face of these factors is unknown. The presence of keratinized gingiva strongly correlated to bone maintenance in the posterior mandible. Because of this statistically significant finding, implant exposure should preserve all keratinized gingiva by transposing it labially to the implants. Most patients who receive implants for dental restoration have lost teeth because of caries and periodontal disease. The patient's behavioural patterns need to be redirected to maintain excellent oral hygiene in order to prevent peri-implant gingivitis. A hygienic restoration may be one of the most important factors associated with excellent implant health. Immediately upon receiving their restoration, patients did well maintaining their peri-implant hygiene. However, many patients do not continue their peri-implant hygiene. However, many patients do not continue their new hygiene methods and need to be strongly reminded to maintain their oral hygiene. Some patients do better than others. For some, a porcelain restoration with the restoration subgingival is well tended, but for others 4 to 5 mm of space needs to be established in order to prevent gingival problems.(ABSTRACT TRUNCATED AT 400 WORDS)     

Long-term treatment outcomes in edentulous patients with implant-fixed prostheses: the Toronto study

PURPOSE: The aim of this prospective study was to report long-term treatment outcomes (prosthetic and implant related) of edentulous patients treated with implant-supported fixed prostheses who participated in the first clinical implant study in North America. MATERIALS AND METHODS: Forty-five patients were treated with Br?nemark implants supporting a total of 47 fixed prostheses (42 mandibular and 5 maxillary) between 1979 and 1984. All patients were recalled regularly for comprehensive prospective clinical and radiographic assessments. RESULTS: Thirty-one patients (33 prostheses) attended a final recall visit in 2002; 71% of patients had been followed for 20 years (range 18 to 23 years), with overall prosthetic plan and implant outcome success rates of 84% and 87%, respectively. Mean marginal bone loss around the implants after the first year of loading was small (0.05 mm/year), with high individual variations. Poor oral hygiene, smoking history, and implant position appeared to be predictors of marginal bone loss. Prosthetic maintenance was ongoing and included fractured components and replacement of prostheses; the longevity of a fixed prosthesis for this group of patients was 8.39+/-5.30 years. CONCLUSION: This study confirmed the overall long-term treatment outcome success of patients treated with fixed prostheses supported by Br?nemark implants. Successful osseointegration with a small mean bone loss was maintained as study patients aged, although prosthetic maintenance was required. The latter consideration should be discussed with all patients seeking such treatment.     

Infectious risks for oral implants: a review of the literature

The use of oral implants in the rehabilitation of partially and fully edentulous patients is widely accepted even though failures do occur. The chance for implants to integrate can for example be jeopardised by the intra-oral presence of bacteria and concomitant inflammatory reactions. The longevity of osseointegrated implants can be compromised by occlusal overload and/or plaque-induced peri-implantitis, depending on the implant geometry and surface characteristics. Animal studies, cross-sectional and longitudinal observations in man, as well as association studies indicate that peri-implantitis is characterised by a microbiota comparable to that of periodontitis (high proportion of anaerobic Gram-negative rods, motile organisms and spirochetes), but this does not necessarily prove a causal relationship. However, in order to prevent such a bacterial shift, the following measures can be considered: periodontal health in the remaining dentition (to prevent bacterial translocation), the avoidance of deepened peri-implant pockets, and the use of a relatively smooth abutment and implant surface. Finally, periodontitis enhancing factors such as smoking and poor oral hygiene also increase the risk for peri-implantitis. Whether the susceptibility for periodontitis is related to that for peri-implantitis may vary according to the implant type and especially its surface topography.