A multicenter 12-month evaluation of single-tooth implants restored 3 weeks after 1-stage surgery

The time-intensive, multi-step process of dental implant therapy limits patient acceptance. This 3-year prospective multicenter study sought to determine the safety of an expedited therapy that consisted of loading unsplinted maxillary anterior single-tooth implants 3 weeks after 1-stage surgical placement, and determination of the peri-implant cortical bone and mucosal responses to the expedited procedure. Fifty-two patients missing 1 or 2 maxilliary anterior teeth were enrolled in a study approved by the Institutional Committee on Human Subjects Research and based on strict inclusion and exclusion criteria. Astra Tech ST implants placed in a 1-stage procedure were restored 3 weeks later with ST abutments and a provisional crown (baseline); 7 to 9 weeks later, a porcelain-fused-to-metal or all-ceramic crown was cemented. Radiographic and clinical examinations were made at baseline and at 6 and 12 months. Implant survival was recorded. Cortical bone responses and peri-implant mucosal responses were evaluated. Fifty-eight implants were placed. During the 3-week period after implant placement, 4 patients were dismissed because of smoking cigarettes (a protocol deviation), and 1 patient was excluded because of deviation in loading time. Of the remaining 53 implants, 2 failed before definitive crown cementation. The resultant 96.2% survival rate was independent of implant length, tooth position, and bone quality/quantity. The mean change in marginal bone level was 0.4 mm at 12 months. The number of surfaces with plaque decreased from 3.4% at baseline to 0.5% at 12 months. The surfaces with inflammation also decreased. A mean gain in papilla length of 0.61 mm occurred, and a gain in buccal gingiva (x = 0.34 mm) was observed. A high success rate with positive tissue responses was achieved for maxillary anterior unsplinted single-tooth implants placed in a 1-stage surgery and restored at 3 weeks. This 2-component system is suited to a single-stage, rapid loading protocol for esthetic single-tooth replacement.     

A short-term clinical evaluation of immediately restored maxillary TiOblast single-tooth implants

PURPOSE: The purpose of this study was to evaluate the short-term clinical outcome of single-tooth implants placed in the maxilla and immediately restored using cementless friction-fit temporary crowns. MATERIALS AND METHODS: Twenty-five patients consecutively referred to a private specialist practice for the replacement of failing or missing maxillary teeth were treated by means of immediate temporization of their single-tooth implants. Where teeth were still present, implants were placed immediately following extraction. Provisional crowns were fabricated on a special friction-fit coping by means of autopolymerizing acrylic resin. Definitive crowns were placed a mean of 4.5 months after surgery. Implant survival was recorded along with the level of the marginal bone relative to a fixed reference point 1 year after placement. Any adverse soft tissue changes were also noted. RESULTS: A total of 28 Astra Tech ST dental implants were placed. The overall survival rate at the end of the study was 96.4% for implants which were in function for periods ranging from 15.7 to 27 months. One patient, a smoker, lost 1 implant within 1 month of surgery. Mean marginal bone loss was 0.40 mm (range 0 to 1.53 mm) 1 year after placement of the implants. Many implants (37.5%) had no observed bone loss. No implants or crowns have been lost during the functional loading period. One implant was associated with an unfavorable recession of soft tissues; however, most maintained an esthetic gingival architecture. Eleven of 28 provisional restorations needed treatment; 6 required replacement during the temporization period, and 5 required cementation because of looseness. The ease of removal of the crowns allowed regular access for irrigation with chlorhexidine and thus maintenance of soft tissue health. DISCUSSION: The need to provide provisional restorations for single-tooth gaps often presents challenges. An immediate temporary partial denture or adhesive prosthesis may be unacceptable or impractical. The current study describes a simple method for the immediate temporization of single-tooth implants. The results did not indicate any negative influence on osseointegration or short-term survival once the implants were functionally loaded. CONCLUSION: Immediate temporization of maxillary single-tooth implants can be both safe and predictable, and it appears that the procedure can yield favorable soft tissue esthetics.     

Immediately restored one-piece single-tooth implants with reduced diameter: one-year results of a multi-center study

Objectives: The aim of the present multi‐center study was to evaluate the treatment outcome of immediately restored one‐piece single‐tooth implants with a diameter of 3 mm after 1 year. Material and methods: A total of 57 one‐piece implants (NobelDirect^® 3.0) were inserted in 47 patients (26 females, 21 males) with a mean age of 31 years (range: 17–76 years) at five different centers. The implants replaced maxillary lateral incisors and mandibular incisors. The implants were placed either in conjunction with tooth extraction or in healed sites, and all implants were immediately restored with a provisional resin crown. If needed, the abutment part of the implant was prepared before crown cementation. The permanent crown was placed after 1.9–14.5 months. Radiographs were taken at implant insertion as well as after 6 and 12 months to evaluate the peri‐implant marginal bone level and bone loss. Moreover, plaque, bleeding on probing and complications were assessed. Results: A total of 44 patients (23 females, 21 males) with 54 implants were available for the 1‐year follow‐up. One implant was lost, thus the 1‐year implant survival was 98%. A statistically significant mean marginal bone loss was observed between baseline and 6 months (1.1 mm, range: ?0.7 to 4.4 mm; n=49) and between baseline and 12 months (1.6 mm, range: ?0.8 to 4.6 mm; n=50). A total of 18% of the implants were characterized by a bone loss of more than 3 mm. No bleeding on probing was observed around 83% of the implants. Plaque was registered at 15% of the implants. The most common complications were related to the provisional crown, i.e. fracture (n=3) and loss of retention (n=3). Conclusions: A high 1‐year implant survival was observed in the present study. However, the excessive peri‐implant marginal bone loss around several implants indicates that this implant should be used with caution until further studies have been conducted. To cite this article:
Zembi? A, Johannesen LH, Schou S, Malo P, Reichert T, Farella M, Hämmerle CHF. Immediately restored one‐piece single‐tooth implants with reduced diameter: one‐year results of a multi‐center study.
Clin. Oral Impl. Res. 23 , 2012; 49–54.
doi: 10.1111/j.1600‐0501.2011.02174.x     

Prospective clinical evaluation of dental implants with sand-blasted, large-grit, acid-etched surfaces loaded 6 weeks after surgery.

Twenty implants with sand-blasted, large-grit, acid-etched (SLA) surfaces (ITI Dental System) were followed up for a period of 12 months, during which the following clinical criteria were evaluated: (a) absence of persistent clinical symptoms (pain, strange sensations, or paresthesia) after the placement of implants; (b) absence of recurring peri-implant inflammation or suppuration; (c) absence of increasing mobility, tested with Periotest; and (d) absence of bone loss or radiolucency around the implants. After 12 months of follow-up, all the loaded implants, after 6 weeks of placement, were approved under all the aforementioned criteria. During the analysis of the increasing mobility, tested with Periotest, and grouping these implants according to the site of implantation (mandible or maxilla), it was possible to observe that the implants presented the same increasing mobility.     

A retrospective evaluation of 1,387 single-tooth implants: a 6-year follow-up

BACKGROUND: The aim of this study was to evaluate the overall survival rate and factors that affect the clinical outcome of 1,387 consecutively placed implant-supported single restorations up to 6 years. METHODS: During 6 years (1999 to 2005), 1,387 implants were placed in 1,215 subjects (1,073 males and 142 females) who required single-tooth replacements. The average time from implant placement was 2.7 +/- 3.27 years. Implants were mostly placed in the maxillary premolar area (39.5%) followed by the anterior maxillary area (28.7%). Implant survival and location, need for bone augmentation, and implant dimensions were recorded and analyzed. RESULTS: Failed implants totaled 96, resulting in an overall survival rate of 93.1%. The vast majority of failures (94.8%) occurred during the first year following implant placement. Bone augmentation was performed in 9.7% of the implants with a 92.5% survival rate, similar to the survival rate of non-augmented areas (93.1%; P = 0.79). The average implant length was 13.3 mm, ranging from 8 to 16 mm. Longer implants (> or =11 mm) showed similar survival rates as implants <11 mm (93.2% versus 90.2%, respectively; P = 0.4). Implant width ranged between 3.25 to 5 mm (mean 3.9), with no effect on implant survival (P = 0.43). There was a significant difference in implant survival according to the anatomic zone of implant placement (P = 0.0075). The maxillary premolar area showed the highest survival rate (96.2%). CONCLUSION: Implant-supported single-tooth replacement is a predictable procedure with good survival rates up to 6 years.     

Radiographic and clinical evaluation of single-tooth Biolok implants: a 5-year study

PURPOSE: The purpose of this prospective clinical and radiographic study was to evaluate Biolok implants used for single-tooth replacement during 5 years of function. MATERIALS AND METHODS: Thirty-nine patients received Biolok implants for single-tooth replacement. Clinical and radiographic recordings were made at baseline (placement of restoration) and at 1, 3, and 5 years. Plaque Index (PI), Gingival Index (GI), and clinical attachment level were the clinical parameters recorded. Clinical attachment level was measured using a customized probing template and a standard pressure electronic probe. Bone level changes were measured from standardized radiographs. Clinical attachment level and bone level were recorded to the nearest 0.1 mm. Correlations between clinical attachment level, bone level, PI, and GI were evaluated. RESULTS: The cumulative survival rate was 97.4% (38 of 39 implants). The mean clinical attachment level change over 5 years was a loss of 0.17+/-0.23 mm. Significant correlations between clinical attachment level change and PI were found at 3 and 5 years (P < .015). Significant correlations between clinical attachment level change and GI were not found (P >.05). Mean bone loss was 0.83+/-0.03 mm from baseline to 1 year, 0.26+/-0.03 mm from 1 year to 3 years, and 0.14+/-0.04 mm from 3 to 5 years. Significant correlations between bone level changes and PI or GI were not found (P > .05). DISCUSSION: Over a 5-year evaluation period, the bone levels and clinical attachment levels were stable. These results were consistent with other studies of single-tooth implants. CONCLUSIONS: After 5 years of function, the results suggest that Biolok implants can be successfully used for single-tooth replacement.     

Early functional loading of unsplinted roughened surface implants with mandibular overdentures 2 weeks after surgery

Background: Before early functional loading of unsplinted implants with mandibular overdentures can become widespread, more clinical studies are needed to investigate the success of the approach. Purpose: To evaluate the success rates of two types of roughened titanium surface implants with early 2‐week functional loading of paired mandibular interforaminal implants with overdentures. Materials and Methods: Random allocation divided 24 strictly selected edentulous participants into two groups, with each group to receive a different implant system (ITI Dental Implant System, Straumann AG, Waldenburg, Switzerland; or Southern Implant System, Southern Implants, Irene, South Africa). Two implants were placed in the anterior mandible of all participants using one‐stage standardized surgical procedures. Previously constructed conventional mandibular dentures (opposing maxillary complete dentures) were temporarily relined and worn by the participants for the first 2 weeks; participants used a soft diet. Two weeks after implant surgery and following some mucosal healing, the mandibular dentures had the tissue conditioner removed and the appropriate matrices included for an unsplinted prosthodontic design. Results: No implant from either group was lost. Resonance frequency analysis (RFA) indicated higher primary stability at surgery for the Southern group than for the ITI group, with a statistically significant difference between the groups throughout the study period. The drop in RF values between surgery and 6 weeks was significant and was greater for the Southern group. RFA also indicated stabilized osseointegration between 6 to 12 and 12 to 52 weeks, with no participant showing any decrease in those values over time. Participants with type 3 bone showed a significant improvement in RF values between 12 and 52 weeks, eventually matching those of participants with type 2 bone. There were no significant differences in marginal bone loss, periimplant parameters, or prosthodontic maintenance between the groups over the study period. Conclusions: Using only strict patient selection criteria, 1‐year follow‐up data indicate that early functional loading of ITI and Southern implants with mandibular two‐implant overdentures is possible as early as 2 weeks after implant surgery.     

Status of teeth adjacent to single-tooth implants

PURPOSE: This study evaluated the status of teeth adjacent to single-tooth implants in the anterior and posterior jaw during a follow-up of more than 3 years. MATERIALS AND METHODS: Seventy-eight single-tooth implants and 148 adjacent teeth were followed for a mean of 58 months. Implant survival rate, peri-implant structures, and prosthetic complication rates were evaluated. Crowns and periodontal status of adjacent teeth were compared at crown placement and at the last examination. Horizontal distance from the implant edge to adjacent teeth was calculated and compared for anterior and posterior regions. The influence of approximal crestal bone resorption of the adjacent teeth was calculated using multivariate regression analysis. RESULTS: The clinical findings for implants (one loss), peri-implant structures, and prosthetic complication rates (three crown fractures) were excellent. There was a high proportion of intact adjacent teeth in both anterior and posterior regions at crown placement and at the follow-up examination. No adjacent teeth required extraction or endodontic treatment, and only four required restoration. Comparison of the periodontal status at crown placement and at follow-up revealed no differences for plaque and bleeding indices or for pocket depth of adjacent teeth. There was a significant influence of the horizontal distance on approximal bone loss in the closer distance of the anterior region, but not in the posterior region. CONCLUSION: The crown and periodontal status of teeth adjacent to single-implant restorations was excellent. The approximal bone crest reduction of the adjacent teeth was significantly influenced by the horizontal distance between the implant edge and neighboring tooth.     

Frialit-2种植体在修复前牙缺失中的应用

目的 评价Frialit－2种植体修复前牙缺失的临床疗效。方法 即刻植入组（20例）与常规植入组（34例），共植入66个Frialit－2种植体，均以单冠作义齿修复。结果 经0．5－4年的临床观察，即刻植入组与常规植入组成功率分别为90．0％与96．6％。结论 常规植入组的疗效优于即刻植入组；FRIALIT－2种植体修复前牙缺失可获得良好的功能与美学效果。     

Tactile sensibility of single-tooth implants and natural teeth

AIM: The purpose of this randomized split-mouth clinical trial was to determine the active tactile sensibility between single-tooth implants and opposing natural teeth and to compare it with the tactile sensibility of pairs of natural teeth on the contralateral side in the same mouth (intraindividual comparison). MATERIAL AND METHODS: The hypothesis was that the active tactile sensibilities of the implant side and control side are equivalent. Sixty two subjects (n=36 from Bonn, n=26 from Bern) with single-tooth implants (22 anterior and 40 posterior dental implants) were asked to bite on narrow copper foil strips varying in thickness (5-200 microm) and to decide whether or not they were able to identify a foreign body between their teeth. Active tactile sensibility was defined as the 50% threshold of correct answers estimated by means of the Weibull distribution. RESULTS: The results obtained for the interocclusal perception sensibility differed between subjects far more than they differed between natural teeth and implants in the same individual [implant/natural tooth: 16.7+/-11.3 microm (0.6-53.1 microm); natural tooth/natural tooth: 14.3+/-10.6 microm (0.5-68.2 microm)]. The intraindividual differences only amounted to a mean value of 2.4+/-9.4 microm (-15.1 to 27.5 microm). The result of our statistical calculations showed that the active tactile sensibility of single-tooth implants, both in the anterior and posterior region of the mouth, in combination with a natural opposing tooth is similar to that of pairs of opposing natural teeth (double t-test, equivalence margin: +/-8 microm, P<0.001, power >80%). Hence, the implants could be integrated in the stomatognathic control circuit.     

Retrospective cohort study of the clinical performance of 1-stage dental implants

PURPOSE: To evaluate long-term clinical performance of 1-stage dental implant prostheses at a single clinic, emphasizing clinical and demographic characteristics that affect implant survival. MATERIALS AND METHODS: Dental records of all 308 patients (674 implants) treated with 1-stage implants at Mayo Clinic from October 1993 through May 2000 were reviewed from implant placement to last visit. Exposure and outcome variables affecting performance were collected separately to control bias in the data collection process. Additional confounding factors (age and sex) were adjusted with the stratified Cox proportional hazards model. Implant survival was determined by means of a Kaplan-Meier survival estimate. The log-rank test was used to determine the role of clinical and demographic variables in implant survival. The relative risk associated with the possible effect of clinical and demographic variables on implant survival was estimated with the Cox proportional hazards model. RESULTS: The implant survival rate (n = 654 implants) was 97% (mean +/- SD follow-up, 21.0 +/- 18.8 months; range, 1 to 78 months). Performance bias was limited because nearly all patients were treated by 1 prosthodontist. Two implants failed after loading (6 and 9 months). The incidence of complications was less than 4%. Among the implant failures, use of heterogeneous bone graft was associated with 4.8 times more failures than was use of autogenous bone graft (P = .04). After augmentation, delaying implant placement for 5 to 6 months resulted in 8.6 times more failures than the rate after earlier placement (P < .001). DISCUSSION: Retrospective review of the clinical performance of a 1-stage dental implant system yielded a 97% survival rate, with no failures noted after 13 months. Prosthetic complications were low, especially for fixed implant prostheses. CONCLUSION: Clinical performance of 1-stage dental implant prostheses between 1993 and 2000 demonstrated a high level of predictability.     

A systematic review of single-tooth restorations supported by implants

OBJECTIVES: To make an inventory of clinical studies on single-tooth restorations supported by implants using a systematic review procedure and to aggregate overall survival results. DATA SOURCES: Papers referring to single-tooth implants were located by a MEDLINE search 1990 to April 1998. Three hundred and twenty references were found, and they were subjected to a systematic review procedure. STUDY SELECTION: A three-step inclusion/exclusion procedure was applied to identify papers that represented: good scientific practice (GSP), reported results of all patients, implants and crowns for more than 2years, and had sufficient data to generate life-table analyses. The outcomes were 'implant failure' and 'crown completion'. Nine studies survived. These data showed an overall mean GSP of 0.37 with a predicted 4year implant survival of 97% (n=459), and an uncomplicated crown maintenance of 83% (n=240). CONCLUSION: Single-tooth implants show an acceptable short-term survival of 4years, but crown complications are common.