Three-year evaluation of single-tooth implants restored 3 weeks after 1-stage surgery

PURPOSE: The possibility of expediting dental implant therapy by early or immediate loading protocols requires long-term clinical investigation. The aim of this prospective cohort trial was to determine the 3-year implant success rate and prosthesis complications associated with functional loading 3 weeks after 1-stage placement of Astra Tech single-tooth implants replacing maxillary anterior teeth. A secondary objective was to determine peri-implant tissue responses at these implants. MATERIALS AND METHODS: The peri-implant bone and mucosal conditions of 43 implants in 39 subjects were radiographically and clinically measured 3 years after implant placement. RESULTS: Of the 48 patients originally treated, 39 patients and 43 implants were examined at the 3-year time point. Three of 54 implants failed within the first year. No additional failures were recorded since the 12-month reporting period. Peri-implant bone levels were stable for the 3-year period following implant placement. The change in marginal bone levels after 3 years was 0.42 +/- 0.59 mm. Papilla growth was measured at 1 and 3 years (0.61 +/- 0.95 mm and 0.74 +/- 0.79 mm, respectively). The buccal peri-implant tissue dimensions at the gingival zenith also increased at 1 and 3 years (0.34 +/- 0.94 mm and 0.51 +/- 1.42 mm, respectively). No abutment screw loosening or fracture occurred. DISCUSSION AND CONCLUSIONS: Early loading of endosseous dental implants placed in healed ridges offers select benefits to clinicians and their patients.     

Radiologic follow-up of peri-implant bone loss around machine-surfaced and rough-surfaced interforaminal implants in the mandible functionally loaded for 3 to 7 years

PURPOSE: In this retrospective study, marginal peri-implant bone height around machined and sandblasted/acid-etched interforaminal implants in the mandible was evaluated radiologically at least 3 years after functional loading. MATERIALS AND METHODS: Fifty-one patients, each with 4 interforaminal screw-type implants placed between 1994 and 1998, were included in this study. Of these, 36 patients (70.6%) with a total of 144 implants (76 machined Mk II implants and 68 sandblasted/acidetched Frios implants) were available for follow-up studies. Interforaminal marginal bone loss was evaluated by extraoral rotational panoramic radiographs. In addition, predictive factors such as patient age and sex, nicotine use, implant position, implant life, and site of measurement were recorded, as well as bone loss at surgery (ie, baseline bone loss). Analysis of covariance for repeated measurements was used for statistical analysis. Between-group differences were expressed as least square means +/- standard error. RESULTS: Sandblasted/acid-etched implants showed significantly less marginal bone loss than machine-surfaced implants (2.4 +/- 0.23 mm vs 1.64 +/- 0.27 mm). Implants placed in the anterior of the arch showed significantly more peri-implant bone loss than implants placed in the posterior (P = .0001). DISCUSSION AND CONCLUSIONS: Significantly less long-term peri-implant bone loss was observed for rough implant surfaces compared to machine-surfaced implants. However, it was also demonstrated that both types of implants, in combination with bar-supported overdentures, can produce excellent long-term results in the atrophic edentulous mandible. Mesially placed implants showed more bone resorption than distally positioned implants, independent of surface roughness.     

A 5-year longitudinal study of the clinical effectiveness of ITI solid-screw implants in the treatment of mandibular edentulism

PURPOSE: The aim of this longitudinal study was to gain 5-year clinical documentation of the 1-stage surgical technique in connection with ITI solid-screw implants used in the edentulous mandible. MATERIALS AND METHODS: One hundred patients with totally edentulous mandibles were treated with bar-retained overdentures supported by a total of 340 consecutively placed ITI solid-screw implants. The patients were followed at annual intervals for at least 5 years to evaluate implant success, longitudinal reactions of the peri-implant hard and soft tissues, and incidences of biologic and mechanical complications. RESULTS: During the trial period, a total of 4 implants failed, all prior to loading, and 51 implants were lost to follow-up, resulting in a cumulative survival rate of 98.8% after 5 years of functional service. The success analysis included additional strictly defined events (either "first occurrence of marginal bone loss > or = 4 mm" or "first occurrence of pocket depth > or = 4 mm" and "first occurrence of crevicular fluid flow rate > or = 2.5 mm) and resulted in a cumulative 5-year success rate of 95.7%. The median marginal bone loss experienced between implant placement and prosthetic treatment was 0.5 mm, followed by an annual bone level change of 0.1 mm for the functional period of 5 years. The increasing incidence of remarkable plaque deposits from 19% to 50% represented the difficulties of the patients in maintaining a high level of oral hygiene, particularly for the lingual surfaces. Sulcus Bleeding Index, probing depth, attachment level, and crevicular fluid flow rate were used to describe the health of the peri-implant soft tissues and remained almost within acceptable standards. DISCUSSION: Survival and success rates of implants, amount of marginal bone loss, and periodontal indices of peri-implant soft tissues were consistent with those reported in the literature regarding implants with the submerged healing concept. CONCLUSION: With a cumulative survival rate of 98.8%, a cumulative success rate of 95.7%, and a median marginal bone loss of 0.5 mm during the healing period, followed by an annual rate of 0.1 mm after loading, non-submerged ITI solid-screw implants confirm the good clinical outcome of implant-supported treatment concepts for the rehabilitation of totally edentulous patients in a medium-term perspective.     

Radiologic study of marginal bone loss around 108 dental implants and its relationship to smoking, implant location, and morphology

PURPOSE: To investigate peri-implant bone resorption around 108 ITI dental implants 1 year after prosthetic loading using extraoral panoramic, conventional intraoral periapical, and digital radiologic techniques. MATERIALS AND METHODS: A total of 108 implants were placed (59 in the maxilla and 49 in the mandible) in 42 patients (16 men and 26 women) with a mean age of 44.2 years (range 14 to 68 years). Orthopantomographic, conventional periapical, and digital radiographs were obtained at loading and again 1 year later. Bone loss was calculated from the difference between the initial and final measurements. RESULTS: Mean loss in alveolar bone height was determined to be 1.36 mm by extraoral panoramic radiography, 0.76 mm by intraoral periapical radiography, and 0.95 mm by digital radiography. The implants located in the maxilla and those placed in patients who smoked 11 to 20 cigarettes per day were associated with significantly greater bone loss. DISCUSSION: The results in relation to peri-implant bone loss in the first year after loading were similar to those published by other authors. CONCLUSION: Conventional periapical films and digital radiographs were more accurate than orthopantomography in the assessment of peri-implant bone loss. Smoking and implant location in the maxilla were associated with increased peri-implant marginal bone resorption.     

A 5-year prospective study on small diameter screw-shaped oral implants

Alveloar ridges of limited dimensions could preclude the placement of dental implants of the regular dimension. Smaller diameter implants - narrow platform (NP) implants were commercially available to address this issue. The aim of the study was to determine the 5-year clinical performance of 3.3 mm diameter NP implants. Twenty-three machined screw-shaped NP implants were placed in nine patients (six males; three females) between 18 and 70 years of age. Clinical and radiographic examinations were performed annually for 5 years. Recognized implant success criteria was used. The criteria were based on the mean marginal alveolar bone loss, the placement of prosthesis of satisfactory appearance, and the absence of implant mobility, peri-implant radiolucency, pain, discomfort or infection. One implant failed at abutment connection. The remaining 22 implants were restored and functioned successfully according to the criteria. The mean marginal alveolar bone loss during the first year was 0.41 +/- 0.17 mm. The mean marginal alveolar bone loss between the second and fifth year was 0.03 +/- 0.06 mm. The success rate of NP implants according to a well-established set of criteria was 96%.     

A 10-year prospective study of ITI dental implants placed in the posterior region. I: Clinical and radiographic results

OBJECTIVES: To evaluate the long-term fixture success rate, crestal bone loss and peri-implant soft tissue parameters around ITI dental implants placed in the posterior region of partially edentulous patients. MATERIAL AND METHODS: A total of 192 ITI dental implants were consecutively placed in premolars and molars of 83 partially edentulous patients admitted for treatment at Geneva Dental School. All implants were restored by means of ceramic-to-metal fused fixed partial dentures and single crowns. Patients were followed as part of a prospective longitudinal study focusing on implant success. Surgical, radiographic and clinical variables were collected at the 1-year recall after implant placement and at the most recent clinical evaluation. RESULTS: The mean observation time was 6 years (range 5-10 years). Four implants failed, yielding a 10-year cumulative survival rate of 97.9%. The mean annual crestal bone loss was -0.04+/-0.2 mm. Hollow-cylinder implants displayed more crestal bone loss (-0.13+/-0.24 mm) than hollow-screw implants (-0.02+/-0.19 mm; P=0.032). Clinical parameters such as age, gender, implant length and bone quality did not affect crestal bone levels. Increase in recession depth (P=0.025) and attachment level (P=0.011) were significantly associated with crestal bone loss. CONCLUSIONS: ITI dental implants placed in the posterior jaw demonstrate excellent long-term clinical success. Hollow-cylinder implants seem to display a higher risk for crestal bone loss. Recession depth and attachment levels appear to be good clinical indicators of peri-implant bone loss.     

Implant-supported single-tooth restorations: a 5-year prospective study

BACKGROUND: Comparatively few studies are available reporting at least 5 years of follow-up data of implant-supported single-tooth replacements. OBJECTIVE: To evaluate prospectively the 5-year outcome of implant-supported single-tooth prosthetic restorations. MATERIAL AND METHODS: Forty subjects (mean age 41 years), 23 males and 17 females, who required single-tooth prosthetic replacement for a missing tooth were recruited. A total of 45 self-tapping implants (Astra Tech ST-implants)--40 in the maxilla and five in the mandible--were installed in a two-stage procedure. Abutment connection was performed 3-6 months after implant installation. Clinical and radiographic examinations were performed at the completion of the prosthetic treatment and once a year during a 5-year follow-up period. The analysis of peri-implant bone level alteration was performed on subject and implant levels and by the use of analysis of variance and binary logistic regression. RESULTS: Three patients were lost during the 5 years of follow-up. One implant was lost after 2.5 years in function and another four implants could not be accounted for at the 5-year follow-up examination. The overall failure rate at 5 years was 2.6% (subject level) and 2.3% (implant level). The mean loss of marginal bone at the implants during the first year in function was 0.06 mm (SD 0.67) on the subject level and 0.02 mm (0.65) on the implant level. During the subsequent 4 years the annual change in peri-implant bone level amounted to -0.02 mm (0.22) on both subject and implant levels. Thus, the mean total bone level change over the 5-year interval was -0.14 mm (1.04) on subject level and -0.11 mm (1.00) on the implant level of analysis (p>0.05). The frequency of implants with a 5-year bone loss of > or =1 mm was 13%. Approximately 50% of the implants demonstrated no bone loss. CONCLUSION: The present clinical trial on single-tooth replacements with the Astra Tech implant system demonstrated that the bone loss during the first year of function as well as annually thereafter was small.     

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.     

Long‐term,retrospective evaluation (implant and patient‐centred outcome) of the two‐implant‐supported overdenture in the mandible. Part 2: marginal bone loss

Objective: In part 2 of this long‐term, retrospective study on the two‐implant‐supported overdenture in the mandible, the annual marginal bone loss was evaluated in detail and parameters, with a significant effect on the annual bone loss, were verified. Material and methods: For all 495 patients with an overdenture in the mandible at least 5 years in function, data up to their last follow‐up visit had been collected, including long‐cone radiographs (taken at the abutment connection and after years 1, 3, 5, 8, 12 and 16 of loading) and probing data at their last evaluation. General information (medical history, implant data, report on surgery) was retrieved from the patient's file. Two hundred and forty‐eight patients had been clinically examined recently. For the others, information on bone level and probing depths were retrieved from the patient's files, as all patients had been enrolled in our annual follow‐up schedule. Results: The mean annual bone loss on a site level (without considering the first year of bone remodelling) after 3 years of loading was 0.08 mm/year (SD=0.22, n=1105), after 5 years of loading 0.07 mm/year (SD=0.14, n=892), after 8 years of loading 0.06 mm/year (SD=0.12, n=598), after 12 years 0.04 mm/year (SD=0.07, n=370) and 0.05 mm/year (SD=0.05, n=154) after 16 years of loading. Ongoing bone loss was seen in a number of implants (n=26) with the annual bone loss exceeding 0.2 mm. Some factors clearly showed a significant impact on bone loss: smoking (≥10 cigarettes/day), GBR, the presence of dehiscence and bone quantity(the latter only during the first year). The probing data showed a favourable condition, with <1.2% of the approximal pockets being ≥6 mm, and 4.1%=5 mm. Conclusions: The mean annual bone loss over the study period was <0.1 mm/year after the first year of loading. However, a small number (2.5%) of the implants showed continuing bone loss. To cite this article :
Vercruyssen M, Quirynen M. Long‐term, retrospective evaluation (implant and patient‐centred outcome) of the two‐implants‐supported overdenture in the mandible. Part 2: marginal bone loss.
Clin. Oral Impl. Res. 21 , 2010; 466–472.
doi: 10.1111/j.1600‐0501.2009.01902.x     

Evaluation of peri-implant bone loss around platform-switched implants

This clinical and radiographic prospective study evaluated bone loss around two-piece implants that were restored according to the platform-switching protocol. One hundred thirty-one implants were consecutively placed in 45 patients following a nonsubmerged surgical protocol. On 75 implants, a healing abutment 1 mm narrower than the implant platform was placed at the time of surgery. On the remaining implants, a healing abutment of the same diameter as the implant was inserted. All implants were positioned at the crestal level. Clinical and radiographic examinations were performed prior to surgery, at the end of surgery, 8 weeks after implant placement, at the time of provisional prosthesis insertion, at the time of definitive prosthesis insertion, and 12 months after loading. The data collected showed that vertical bone loss for the test cases varied between 0.6 mm and 1.2 mm (mean: 0.95 +/- 0.32 mm), while for the control cases, bone loss was between 1.3 mm and 2.1 mm (mean: 1.67 +/- 0.37 mm). These data confirm the important role of the microgap between the implant and abutment in the remodeling of the peri-implant crestal bone. Platform switching seems to reduce peri-implant crestal bone resorption and increase the long-term predictability of implant therapy.     

Peri-implant bone loss around posterior mandible dental implants placed after distraction osteogenesis: preliminary findings

BACKGROUND: The present study evaluates implant survival and peri-implant bone loss around posterior mandible dental implants placed at sites of distraction osteogenesis. METHODS: On removal of the distraction devices, 34 dental implants were inserted into 14 posterior mandible sites in 10 healthy, non-smoking female patients. Prosthetic treatment was performed 4 months after implant placement using fixed implant prostheses. After 6 to 16.5 months, periapical radiographs were taken and evaluated for peri-implant bone loss and radiolucency. The distance between the implant margin and the first visible bone-implant contact was measured on the mesial and distal aspects of the implants using imaging software. Radiographic dimensional distortion was corrected as a function of the known true dimension of the implant. RESULTS: Of the 34 implants placed, two (5.9%) failed to integrate at reentry surgery. Both were replaced and restored during the course of the study so that a total of 34 implants was followed for 12.1 +/- 3.8 months post-restoration and 16.1 +/- 3.8 months post-insertion. Mean loss of marginal bone height was 2.6 +/- 1.0 mm. During the follow-up period, radiolucent lines along the implant surface were absent. CONCLUSIONS: The mean peri-implant bone loss in areas of alveolar bone distraction was 1.9 mm/year. A high implant survival rate was observed.     

The longitudinal clinical effectiveness of ITI solid-screw implants in partially edentulous patients: a 5-year follow-up report

A total of 114 ITI solid-screw implants was consecutively placed in 55 partially edentulous patients and restored with 68 fixed prostheses. The patients were followed for at least 5 years in a prospective study that focused on implant success and longitudinal reactions of the peri-implant hard and soft tissues. During the study period, 5 implants failed and 15 implants were lost to follow-up, resulting in a cumulative survival rate of 95.3% after 5 years of loading. The success analysis included additional strictly defined events ("first occurrence of marginal bone loss > or = 4 mm," "first occurrence of pocket depth > or = 4 mm," and "first occurrence of crevicular fluid volume > or = 2.5 mm") and resulted in a cumulative 5-year success rate of 89.0%. Median loss of marginal bone, as observed on radiographs, was 0.7 mm between implant placement and prosthetic treatment and 0.5 mm between prosthesis placement and the 5-year evaluation. Compared to the previous year's value, the annual increase in marginal bone loss did not reach a level of statistical significance between 1 and 5 years of function, so that a steady state prevailed. The incidence of lingual-palatal surfaces affected with remarkable plaque deposits increased from 13% after prosthesis placement to 23% after 5 years. Sulcus Bleeding index, probing depth, attachment level, and crevicular fluid volume were used to describe the health of the peri-implant soft tissues. The research parameters remained almost unchanged and indicated a soft tissue response within physiologic levels. Most mechanical complications were experienced during the first year of loading and were related to loosening of occlusal screws, which occurred in 8 (12%) of 68 restorations.     

Multiple teeth replacement with endosseous one-piece yttrium-stabilized zirconia dental implants

Objectives: The purpose of this study is to clinically and radiographically evaluate survival and success rate of multiple zirconia dental implants positioned in each patient during a follow-up period of at least 12 months up to 48 months. Study Design: Eight patients were treated for multiple edentulism with 29 zirconia dental implants. All implants received immediate temporary restorations and 6 months after surgery were definitively restored. 6 months to 4 years after implant insertion, a clinical-radiographic evaluation was performed in order to estimate peri-implant tissues health and peri-implant marginal bone loss. Results: Survival rate within follow-up period was therefore 100%. The average marginal bone loss (MBL) from baseline to 6 months was +1.375±0.388 mm; from 6 months to 1 year was +0.22±0.598 mm; from 1 year to 2 years was -0.368±0.387 mm; from 2 years to 3 years was -0.0669±0.425 mm; from 3 years to 4 years +0.048±0.262 mm. The mean marginal bone loss at 4 years from the implants insertion was +1.208 mm. Conclusions: According to several studies, when using a radiographic criterion for implant success, marginal bone loss below 0.9-1.6 mm during the first year in function can be considered acceptable. In our work, radiographic measurements of MBL showed values not exceeding 1.6 mm during the first year of loading and also 1 year up to 4 years after surgery further marginal bone loss was minimal and not significant. This peri-implant bone preservation may be associated to the absence of micro-gap between fixture and abutment since zirconia dental implants are one-piece implant. Moreover, zirconia is characterized by high biocompatibility and it accumulates significantly fewer bacteria than titanium. Key words:Zirconia dental implants, multiple implants, radiographic evaluation, marginal bone loss (MBL).     

Long-term clinical evaluation of tapered multi-threaded implants: results and influences of potential risk factors

This prospective study evaluated the long-term performance of tapered screw implants placed in patients with a variety of potentially compromising clinical variables. Sixty patients were treated with 218 implants; each case included one or more potential risk factors associated with increased rates of implant failure, peri-implant bone loss or clinical complications in the dental literature: short implants (23%), comorbid conditions (25%), maxillary implants (61%), immediate loading (88.5%), placement into extraction sockets (91%), and partial edentulism (97%). The implants were restored with a variety of prostheses. Marginal bone changes were calculated utilizing periapical radiographs taken at placement and at all subsequent appointments utilizing a standardized paralleling device and a 1-mm measurement grid. Mean clinical follow-up was 67.5 (range: 1-94) months for implants and 60 (range: 15-74) months for prostheses. Four implants failed to integrate and were immediately replaced by wide-diameter implants. Eight prostheses sustained porcelain fracture (n = 7) or cement failure (n = 1) and were replaced. No peri-implant marginal bone loss was observed for 98% of the implants; the remaining 2% exhibited 1 mm of bone loss. Cumulative survival rates were 98.2% for implants and 96.3% for prostheses after 5 years of clinical loading. Concerns that tapered implant designs may be more prone to crestal bone loss than cylinder designs are unsupported by the results of this study. Tapered implants maintained integration and marginal bone levels despite the presence of one or more potentially compromising variables.     

Retrospective clinical evaluation of tapered screw-vent implants: results after up to eight years of clinical function

Uncertainty about the causes of peri-implant bone loss and difficulties in measuring it often have resulted in omission of bone loss data from published long-term implant studies. This nonrandomized, uncontrolled, retrospective study evaluated the clinical outcomes of treatment with tapered, multithreaded implants with a special emphasis on peri-implant crestal bone status. Chart reviews were conducted of 60 patients who had been treated with 267 implants for the placement of 1 or more missing and/or unsalvageable teeth, and who met general inclusion criteria for dental implant therapy. In all cases, marginal bone changes were calculated from the cementoenamel junction (CEJ) or the implant neck to the crestal bone level with standardized radiographs taken at implant placement (baseline) and during annual follow-up. After a mean followup of 7.5 years, implant survival was 98.5% (263/267) for all implants placed, and implant success was 96.2% (253/263) for all surviving implants. No discernible bone loss was evident in 88% of surviving implants. Crestal bone loss was observed in 25% (15/60) of total study subjects and in 12% (32/263) of all surviving implants: 29 implants exhibited 1 mm of bone loss and 3 implants lost 2 mm of bone. Low-density maxillary jawbone and more extensive bone remodeling, which were required around implants immediately placed into extraction sockets, were the probable causes of observed bone loss in this study. Implants exhibited excellent long-term outcomes with little or no bone loss.     

吸烟患者牙种植疗效的临床研究

目的探讨吸烟对种植义齿临床疗效的影响。方法后牙缺失拟行种植修复的患者81例,分为吸烟组和非吸烟组,共植入124颗种植体,于负载后1年随访,检测种植体存留率、边缘骨吸收量、改良菌斑指数（modified plaque index,mPLI）和改良出血指数（modified sulcus bleeding index,mSBI）等临床指标。结果吸烟组有4颗种植体脱落,存留率为92%,非吸烟组种植体存留率为100%,2组差异有统计学意义（χ2=6.090,P=0.028）。吸烟组种植体周围边缘骨吸收量平均为（1.04±0.18）mm,mPLI和mSBI平均水平P50均为1。非吸烟组种植体周围边缘骨吸收量平均为（0.74±0.11）mm,mPLI和mSBI平均水平P50均为0。2组的边缘骨吸收量、mPLI、mSBI差异均有统计学意义（P〈0.05）。结论吸烟是导致种植义齿失败的一个危险因素,吸烟患者种植修复的预后较非吸烟者差。为提高种植义齿的成功率,吸烟患者应尽早戒烟,并保持口腔清洁卫生。     

Oral rehabilitation with implant-supported fixed partial dentures in periodontitis-susceptible subjects. A 5-year prospective study

BACKGROUND: Comparatively few studies with at least 5 years of follow-up are available that describe the use of implants in prosthetic rehabilitation of partially edentulous patients. Randomized, controlled clinical studies that evaluated the effect of different surface designs of screw-shaped implants on the outcome of treatment are also sparse. OBJECTIVE: To determine, in a prospective randomized, controlled clinical trial, the outcome of restorative therapy in periodontitis-susceptible patients who, following basic periodontal therapy, had been restored with implants with either a machined- or a rough-surface topography. MATERIAL AND METHODS: Fifty-one subjects (mean age, 59.5 years), 20 males and 31 females who, following treatment of moderate-to-advanced chronic periodontitis, required implant therapy for prosthetic rehabilitation were recruited. Seventeen of the patients were current smokers. Following the active treatment, all subjects were included in an individually designed maintenance program. A total of 56 fixed partial dentures (FPDs) and a total of 149 screw-shaped, and self-tapping implants (Astra Tech implants) -- 83 in the maxilla and 66 in the mandible -- were installed in a two-stage procedure. Each patient received a minimum of two implants and by randomization every second implant that was installed had been designed with a machined surface and the remaining with a roughened Tioblast surface. Abutment connection was performed 3-6 months after implant installation. Clinical and radiographical examinations were performed following FPD connection and once a year during a 5-year follow-up period. The analysis of peri-implant bone-level alterations was performed on subject, FPD and implant levels. RESULTS: Four patients and four FPDs were lost to the 5 years of monitoring. One implant (machined surface) did not properly integrate (early failure), and was removed at the time of abutment connection. Three implants were lost during function and a further eight implants could not be accounted for at the 5-year follow-up examination. The overall failure rate at 5 years was 5.9% (subject level), 5.3% (FPD level) and 2.7% (implant level). Radiographic signs of loss of osseointegration were not found at any of the implants during the 5-year observation period. During the first year in function there was on average 0.33 (SD, 0.61) mm loss of peri-implant marginal bone on the subject and FPD levels and 0.31 (0.81) mm on the implant level. During the subsequent 4 years, the peri-implant bone-level alterations were small. The calculated annual change in peri-implant bone level was -0.02 (0.15) on subject and FPD levels and -0.03 (0.20) on the implant level. Thus, the mean total bone-level change over the 5-year interval amounted to 0.41 mm on all three levels of analysis. In the interval between baseline and 5 years, the machined and the Tioblast implants lost on average 0.33 and 0.48 mm, respectively (p>0.05). CONCLUSION: The present randomized, controlled clinical trial that included partially edentulous periodontitis-susceptible subjects demonstrated that bone loss (i) during the first year of function as well as annually thereafter was small and (ii) did not vary between implants with machined- or rough-surface designs.     

Clinical parameters associated with success and failure of single-tooth titanium plasma-sprayed cylindric implants under stricter criteria: a 5-year retrospective study

PURPOSE: The purpose of this study was to determine the clinical parameters associated with long-term success and failure of single-tooth titanium plasma-sprayed (TPS) cylindric implants. MATERIALS AND METHODS: Thirty-nine implants in 39 subjects were followed for 5 years. The following data were collected: subject age and gender, implant length, implant location, bone density, and implant position in relation to crestal bone. Assessments made at recall intervals included: Gingival Index (GI), probing depth, relative attachment level, and standardized radiographs. Failure was defined as a mean annual attachment loss rate (ALR) of > or = 0.25 mm after the first year of implant function. Between-group differences were assessed nonparametrically using the Mann-Whitney and chi-square tests. RESULTS: Nineteen implants were considered successes and 20 were considered failures with respective mean ALRs of 0.12 +/- 0.07 mm and 0.42 +/- 0.19 mm. The following factors were associated with success: longer implants (P < .001), lower GI (P < .001), higher bone density (P < .0001), and implant position at the crest or supracrestally (P <.0001). Age, gender, probing depth, and implant location were not related to outcome. CONCLUSIONS: A model using attachment loss as a parameter for success and failure has not been previously utilized. Longer implants, lower GI, higher bone density, and implant position at the crest or supracrestally were clinical factors associated with long-term success of single-tooth TPS cylindric implants in this patient population.     

Within-subject comparison between connected and nonconnected tooth-to-implant fixed partial prostheses: up to 14-year follow-up study

PURPOSE: This long-term follow-up study aimed to compare the outcome of fixed prostheses supported by teeth and implants and by freestanding implants only. MATERIALS AND METHODS: From prosthesis insertion up to 14 years (mean 6.5 y), 18 patients were followed. Implant-supported prostheses with and without tooth connection were compared within the same jaw. The tooth-implant prostheses were supported by 30 implants and 30 teeth, and the freestanding prostheses were supported by 48 implants. Implant outcome, marginal bone stability, and mechanical complications were recorded. RESULTS: Neither implant mobility nor fractures of any component of the implants were observed. No prosthesis complications were observed, and the same applied for crown cement failure and intrusion of teeth. Only one periapical lesion was detected at the first follow up. The annual change of the marginal bone level around connected and freestanding implants did not differ significantly. The mean marginal bone loss (over the 2 groups) for the first 6 months amounted to 1.08 mm. After the first 6 months, an annual marginal bone loss of 0.015 mm was observed. There was no difference between the 3 connection types (single implant connected to single tooth, multiple implants and/or multiple teeth connected with single connector, and multiple connectors) for the first 6 months or thereafter. The marginal bone loss (over the 3 groups) for the first 6 months was 1.15 mm. After the first 6 months, the annual bone loss (over the 3 groups) amounted to 0.015 mm. CONCLUSION: Based on the results of this study, splinting teeth with implants for implant-supported fixed prostheses did not affect the long-term outcome in comparison to freestanding implants.     

Influence of alcohol and tobacco habits on peri-implant marginal bone loss: a prospective study

A prospective clinical study was conducted to explore the possible link between peri-implant bone loss and the widespread habits of tobacco smoking and alcohol consumption. One hundred and eighty-five patients who received 514 implants were followed up for 3 years. Peri-implant marginal bone loss was evaluated by digital panoramic radiography and image analysis techniques. Multivariate analysis showed that peri-implant marginal bone loss was significantly related to a daily consumption of >10 g of alcohol, tobacco use and increased plaque levels and gingival inflammation. The present results indicate that daily alcohol consumption and tobacco use may have a negative influence on predictable long-term implant treatment outcomes, producing peri-implant bone loss and compromising restorative treatment with implant-supported prostheses.