The Up-to-14-Year Survival and Complication Burden of 256 TiUnite Implants Supporting One-Piece Cast Abutment/Metal-Ceramic Implant-Supported Single Crowns

PURPOSE

To assess the estimated cumulative survival (ECS) and explore the technical and biologic complications of 256 TiUnite implants (Nobel Biocare) supporting one-piece cast abutment/metal-ceramic implant-supported single crowns (ISCs) in situ for up to 14 years.

MATERIALS AND METHODS

A prospective sequentially recruited cohort of 207 patients received 256 metal-ceramic ISCs on TiUnite implants between 2001 and 2014. All but 24 patients with 27 crowns were clinically evaluated between January 2014 and April 2015 in conjunction with or in addition to their tailored maintenance program. Radiographs were obtained, and any previously recorded treatments associated with the crowns were tabulated. The ECS and standard errors were calculated with the life table actuarial method and Greenwood's formula, respectively. The log rank test was applied to assess differences between anterior and posterior crowns. Complication incidence, severity, and economic burden, measured in time/cost accounting units (TAUs), were tallied and compared descriptively. Independent groups were compared with the Mann-Whitney U test and related groups with the Wilcoxon Signed Rank Test.

RESULTS

The mean clinical service time of the crowns was 5.61 years (44 ≥ 10 years). The 14-year ECS was 95.95% ± 3.20% with no significant difference between anterior and posterior prostheses. Only seven implants lost marginal bone ≥ one thread from the time of crown insertion. There were 30 nonterminal complications (16 biologic, 14 mechanical). The associated economic burden was low (n = 35 TAUs).

CONCLUSION

High gold-alloy one-piece cast abutment/metal-ceramic ISCs on TiUnite implants exhibited excellent longevity and few complications over 14 years.

Interdisciplinary index of prosthodontic/substitution orthodontic treatment need for patients with missing teeth

The need for treatment in cases of missing teeth may result from aesthetic demands or functional impairment, although tooth loss itself does not necessarily constitute a need for prosthetic replacement. In selected cases, restorative treatment can be replaced by tooth autotransplantation or substitution orthodontic treatment. The authors have tried to make an index based not on missing particular teeth, but on the presence of spacing requiring restoration. An attempt has been made to categorize the restorative treatment need. Orthodontic treatment was considered, when it could completely eliminate the need for prosthetic treatment. The proposed classification could be used for assessing eligibility for public refund of restorative or substitution orthodontic treatment, as well as to motivate the patients to have restorations. It should be an individual approach-based decision, which treatment: orthodontic substitution tooth movement or prosthodontic is more cost-effective for the rest of the patient's life.

Systematic review of the survival rate and incidence of biologic, technical, and esthetic complications of single implant abutments supporting fixed prostheses

PURPOSE

To assess the 5-year survival rate and number of technical, biologic, and esthetic complications involving implant abutments.

MATERIALS AND METHODS

Electronic (Medline) and hand searches were performed to assess studies on metal and ceramic implant abutments. Relevant data from a previous review were included. Two reviewers independently extracted the data. Failure and complication rates were analyzed, and estimates of 5-year survival proportions were calculated from the relationship between event rate and survival function. Multivariable robust Poisson regression was used to compare abutment characteristics.

RESULTS

The search yielded 1,558 titles and 274 abstracts. Twenty-four studies were selected for data analysis. The survival rate for ceramic abutments was 97.5% (95% confidence interval [CI]): 89.6% to 99.4%) and 97.6% (95% CI: 96.2% to 98.5%) for metal abutments. The overall 5-year rate for technical complications was 11.8% (95% CI: 8.5% to 16.3%), 8.9% (95% CI: 4.3% to 17.7%) for ceramic and 12.0% (95% CI: 8.5% to 16.8%) for metal abutments. Biologic complications occurred with an overall rate of 6.4% (95% CI: 3.3% to 12.0%), 10.4% (95% CI: 1.9% to 46.7%) for ceramic, and 6.1% (95% CI: 3.1% to 12.0%) for metal abutments.

CONCLUSIONS

The present meta-analysis on single-implant prostheses presents high survival rates of single implants, abutments, and prostheses after 5 years of function. No differences were found for the survival and failure rates of ceramic and metal abutments. No significant differences were found for technical, biologic, and esthetic complications of internally and externally connected abutments.

A retrospective analysis of patients referred for implant placement to a specialty clinic: indications, surgical procedures, and early failures

PURPOSE

This retrospective study analyzed the pool of patients referred for treatment with dental implants over a 3-year period in a referral specialty clinic.

MATERIALS AND METHODS

All patients receiving dental implants between 2002 and 2004 in the Department of Oral Surgery and Stomatology, University of Bern, were included in this retrospective study. Patients were analyzed according to age, gender, indications for implant therapy, location of implants, and type and length of implants placed. A cumulative logistic regression analysis was performed to identify and analyze potential risk factors for complications or failures.

RESULTS

A total of 1,206 patients received 1,817 dental implants. The group comprised 573 men and 633 women with a mean age of 55.2 years. Almost 60% of patients were age 50 or older. The most frequent indication for implant therapy was single-tooth replacement in the maxilla (522 implants or 28.7%). A total of 726 implants (40%) were inserted in the esthetically demanding region of the anterior maxilla. For 939 implants (51.7%), additional bone-augmentation procedures were required. Of these, ridge augmentation with guided bone regeneration was performed more frequently than sinus grafting. Thirteen complications leading to early failures were recorded, resulting in an early failure rate of 0.7%. The regression analysis failed to identify statistically significant failure etiologies for the variables assessed.

CONCLUSIONS

From this study it can be concluded that patients referred to a specialty clinic for implant placement were more likely to be partially edentulous and over 50 years old. Single-tooth replacement was the most frequent indication (> 50%). Similarly, additional bone augmentation was indicated in more than 50% of cases. Adhering to strict patient selection criteria and a standardized surgical protocol, an early failure rate of 0.7% was experienced in this study population.

A systematic review of the 5-year survival and complication rates of implant-supported single crowns

OBJECTIVES

The objective of this systematic review was to assess the 5-year survival of implant-supported single crowns (SCs) and to describe the incidence of biological and technical complications.

METHODS

An electronic MEDLINE search complemented by manual searching was conducted to identify prospective and retrospective cohort studies on SCs with a mean follow-up time of at least 5 years. Failure and complication rates were analyzed using random-effects Poisson's regression models to obtain summary estimates of 5-year proportions.

RESULTS

Twenty-six studies from an initial yield of 3601 titles were finally selected and data were extracted. In a meta-analysis of these studies, survival of implants supporting SCs was 96.8% [95% confidence interval (CI): 95.9-97.6%] after 5 years. The survival rate of SCs supported by implants was 94.5% (95% CI: 92.5-95.9%) after 5 years of function. The survival rate of metal-ceramic crowns, 95.4% (95% CI: 93.6-96.7%), was significantly (P=0.005) higher than the survival rate, 91.2% (95% CI: 86.8-94.2%), of all-ceramic crowns. Peri-implantitis and soft tissue complications occurred adjacent to 9.7% of the SCs and 6.3% of the implants had bone loss exceeding 2 mm over the 5-year observation period. The cumulative incidence of implant fractures after 5 years was 0.14%. After 5 years, the cumulative incidence of screw or abutment loosening was 12.7% and 0.35% for screw or abutment fracture. For supra-structure-related complications, the cumulative incidence of ceramic or veneer fractures was 4.5%.

CONCLUSION

It can be concluded that after an observation period of 5 years, high survival rates for implants and implant-supported SCs can be expected. However, biological and particularly technical complications are frequent.

Do longer implants improve clinical outcome in immediate loading?

It is generally believed that longer implants (length >13 mm) have higher success rates than standard implants (length=13 mm). Few reports focus on long implants and none specifically address the clinical outcome of immediate loading (IL) of longer implants. This retrospective study was performed to compare the clinical outcomes of long and standard length implants. A total of 244 standard and 536 long implants were inserted and immediately loaded. The mean follow-up was 3 years. Only 4 of 780 implants (99.5%) were lost, and these 4 were all 13 mm long. No or reduced marginal bone loss was taken as an additional indicator of success to evaluate the effect of several factors on clinical outcome. Only 4 of the 244 13-mm-long implants were lost (98%), but this was statistically different from the survival rate of longer implants. Poor quality bone was related to increased marginal bone loss and thus a worse outcome in both groups. IL standard length implants have a high survival rate, but it is statistically worse than that of IL longer implants. Standard or longer implants are reliable devices for insertion in poor quality bone, although slightly higher bone resorption is to be expected.

A 10-year prospective study of ITI dental implants placed in the posterior region. II: Influence of the crown-to-implant ratio and different prosthetic treatment modalities on crestal bone loss

OBJECTIVE

To evaluate the influence of the crown-to-implant ratio (C/I) ratio and different implant prosthetic treatment modalities on crestal bone loss around dental implants placed in the posterior region.

MATERIAL AND METHODS

A total of 192 ITI dental implants were consecutively placed in premolars and molars of 83 partially edentulous patients. All implants were restored by means of ceramic-to-metal fused fixed partial dentures or a single crown. 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. Radiographic parameters were evaluated on periapical radiographs taken with a standardized long-cone paralleling technique. Implant restorations were divided into three groups according to their respective clinical C/I ratios: (a) 0-0.99, (b) 1-1.99 and (c) >or=2.

RESULTS

The mean clinical C/I ratio was 1.77+/-0.56 mm. A total of 51 implants (26.5%) showed a clinical C/I ratio equal to or greater than 2. In this group, three implants failed, giving a cumulative survival rate of 94.1%. Crestal bone loss was -0.34+/-0.27 mm in group a, -0.03+/-0.15 mm in group b and -0.02+/-0.26 mm in group c. Differences among groups were statistically significant (P=0.009). Mode of retention, splinting or presence of cantilever extensions did not have an effect on crestal bone loss around ITI dental implants.

CONCLUSIONS

Implant restorations with C/I ratios between 2 and 3 may be successfully used in the posterior areas of the jaw.

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.

Retrospective Cross Sectional Comparison of Initial Nonsurgical Endodontic Treatment and Single-Tooth Implants

Initial root canal treatment and the replacement of a single tooth with implants are both viable treatment options, but various success rates have been reported for each treatment modality. This study compared 196 implant restorations and 196 matched initial nonsurgical root canal treatment (NSRCT) teeth in patients for four possible outcomes- success, survival, survival with subsequent treatment intervention and failure. Cross classifications/tabulations were analyzed using Pearson's chi(2) test for association of the two classifications (endo vs. implant and outcome). Polytomous regression with likelihood ratio tests were used in testing association with tooth location and outcome. Outcomes were as follows for implants and NSRCT outcomes, respectively: success 73.5% and 82.1%; survival with no intervention 2.6% and 8.2%; survival with intervention 17.9% and 3.6%; and failure 6.1% and 6.1%. Location of the restoration in the mouth did not affect outcome. This study suggests that restored endodontically treated teeth and single-tooth implant restorations have similar failure rates, although the implant group showed a longer average and median time to function and a higher incidence of postoperative complications requiring subsequent treatment intervention.

Prevalence of subjects with progressive bone loss at implants

AIM

The aim of the present study was to assess the prevalence of subjects with progressive bone loss at implants with a function time of at least 5 years.

MATERIAL AND METHODS

Radiographs of 1346 patients who had attended annual follow-up visits at the Brånemark Clinic, Public Dental Services, Gothenburg, Sweden were retrieved. Six hundred and sixty-two subjects fulfilled the inclusion criteria. Thus, they all had been provided with implant-supported (Brånemark System) Nobel BioCare, Gothenburg, Sweden) fixed partial or complete dentures or single-tooth replacements with a documented function time in radiographs of at least 5 years. Implants that demonstrated progressive bone loss to a level of > or =3 threads of an implant were detected. The number of subjects who exhibited one or more implants with progressive bone loss to the threshold level was recorded.

RESULTS

Twenty-eight percent of 662 included subjects had one or more implants with progressive bone loss. A logistic regression analysis revealed that the individuals in this group carried a significantly larger number of implants than the subjects in whom no implants with progressive loss were detected (6 vs. 4.8). Furthermore, >30% of the subjects in the group with progressive bone loss had > or =3 identified implants and that about 33% of all such implants in this group exhibited extensive bone loss. Out of the total 3413 implants included in the study, 423 implants (12.4%) demonstrated progressive bone loss.

CONCLUSION

It is suggested that the prevalence of progressive bone loss at implants assessed from subject-based data is higher than that evaluated from implant-based data.

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.

Single-Tooth Implant Restorations: A Retrospective Study

Single-tooth implant restorations are a demanding clinical endeavor. Predictable results can be achieved when clinicians adhere to a recommended protocol for placement and reconstruction. As the demand to use implants to replace single missing teeth increased, so did the demand for superior esthetic outcome and immediate insertion and loading. The present study presents a 6-year audit of single-tooth implant restorations at Riyadh Dental Centre with a survival probability of 93.8% after a 5-year period. The recent trend of immediate insertion and loading results was also encouraging but still needs technical refinement as well as long-term follow-up review between different protocols.

Factors Associated with Implant Recommendation for Single-Tooth Replacement

The use of dental implants for single-tooth replacement has been established as a predictable treatment option; yet, limited data are available as to how frequently this option is recommended to patients. The aim of the present study was to examine the frequency of implant recommendation by general dental practitioners after single-tooth extraction and factors influencing their decision to recommend an implant. All single-tooth extractions performed in 26 general dental practice clinics in Kuwait over a 30-day period were examined. Dentists in these centers used the study form to record demographic data, the type of tooth extracted, reason for extraction, and replacement options presented to the patients. Univariate and logistic regression analyses were used to examine associations between background factors and decisions to recommend implant therapy. A total of 1367 patients (mean age, 37.9 +/- 11.8 years) had an extraction of one tooth during the study period. Forty-three patients were offered implants as a replacement option (3.3% of the total sample; 8.6% of patients who were offered tooth replacement options). Factors associated significantly with the recommendation of an implant by Kuwaiti dentists to their patients included younger age, regular dental maintenance visits, and adequate oral hygiene practices (P < 0.05; binary logistic regression). Dental implant recommendation for single-tooth replacement in the present sample of dentists was low. Factors associated significantly with dentist recommendation of an implant for single-tooth replacement included age, history of dental maintenance, and oral hygiene practices.

Fixed partial denture or single-tooth implant restoration? Statistical considerations for sequencing and treatment

The choice to replace a single missing tooth can be based on the primary decision that the restorability of the tooth is in doubt. Many teeth are decimated by incipient or recurrent caries, trauma, endodontic complications, or periodontal disease which requires extraction. It is our objective to familiarize the participant with literature comparing success rates of fixed partial dentures and single-tooth implant restorations and a repertoire of prosthodontic techniques used in replacement of single missing teeth with osseointegrated dental implants. The fixed partial denture (FPD) has been regarded as the standard of care for some time in replacement of single and multiple missing teeth. Many studies surveying long term survival have been compiled and analyzed to arrive at a generalized outcome. Most of these studies arrive at common conclusions. Studies surveying success of single-tooth implant-supported restorations are not comparably abundant nor survey for comparable time as those for FPDs. Although, many of the outcomes are statistical survival estimates such as Kaplan-Meier survival tables, implant restorations in partially dentate patients are a predictable means of tooth replacement. There are certain factors which make FPD more appropriate and conversely factors which make an implant restoration more appropriate. Indications and contraindications for each treatment scenario will also be reviewed based on the literature and clinical experience. It is hoped that the practitioner will be able to appropriately identify those cases in which either an FPD or an implant restoration is the appropriate treatment option.

Multicenter retrospective analysis of the solid-screw ITI implant for posterior single-tooth replacements

PURPOSE

This report involves the retrospective analysis of ITI implants placed and/or restored by a group of 7 clinicians located throughout the United States (5 periodontists and 2 prosthodontists).

MATERIALS AND METHODS

Six hundred seventy-five posterior single-tooth implants were restored in 471 patients (average time of loading 21.30 months, with a range of 1 to 78 months). Three hundred seventy implants and 71 implants were placed in mandibular and maxillary molar sites, respectively, and 108 and 126 were placed in mandibular and maxillary premolar sites, respectively.

RESULTS

A cumulative survival rate of 99.1% was obtained for all sites (6 failures). The survival rates for individual sites were as follows: 98.4% mandibular molars, 100% maxillary molars, 100% mandibular premolars, and 100% maxillary premolars. "At-risk" implants (1 to 2 mm of radiographic bone loss) were noted at 5 sites.

DISCUSSION

Minimal restorative problems were found with either screw-retained (n = 71) or cemented restorations on solid abutments (n = 600); 80.3% of screw-retained and 98.2% of cemented restorations were free of complications, respectively. Patient satisfaction scores were high (97.4%) as determined by the Patient Satisfaction Questionnaire.

CONCLUSION

The data suggest that solid-screw (4.1 or 4.8 mm wide) ITI implants can be a satisfactory choice for posterior single-tooth restorations.

Long-term clinical effectiveness of oral implants in the treatment of partial edentulism. Seven-year life table analysis of a prospective study with ITI dental implants system used for single-tooth restorations

One hundred and eight-seven ITI implants were prospectively followed from November 1992 to July 2000, in order to evaluate the clinical efficiency and the long-term prognosis in 109 partially edentulous patients (69 women and 40 men; average age 41.3 years). Of these 187 implants, 69.5% were placed in the mandible and 30.5% in the maxilla. After a healing period that ranged from three to six months, the osseointegrated implants (n = 184) were restored with single crowns. Three implants were extracted prior to loading the fixture and were considered early failures. Each implant was reassessed on a yearly basis, both clinically and radiographically. The results of the investigation, which were evaluated according to predefined success criteria, were reviewed in accordance with a life table method. During the follow-up, six cases were deemed to be late failures. In each of these cases, a suppurative infection of the peri-implant tissue was diagnosed: in one implant, the infection could not be eradicated and the implant was removed. When 11 drop-outs were included in the analysis, the cumulative survival and success rates for the whole sample group were 96.77% and 93.6%, respectively. When only prosthetically loaded implants were considered, the results increased to 99.35% for the cumulative survival rate and 96.18% for the cumulative success rate. The analysis on disaggregated data showed better results for maxillary restorations (survival rate 100%) in comparison to mandible restorations (survival rate 95.11%). It was concluded that, under standard anatomic conditions (bone site height > 8 mm, thickness > 6 mm), prosthetic restoration of partially edentulous patients with the ITI system can be described as a reliable and efficient therapy in the long term.

A long-term follow-up of 76 Bränemark single-tooth implants

In a previous study (Haas et al. 1995), we reported on preliminary results of 76 Brånemark implants placed in 71 patients with single-tooth gaps. The present study examines the results of the same group over a longer period of time: 55 implants were followed for more than 5 years, 12 for a period between 4 and 5 years and 1 implant for 46 months. One patient died 3 years after implant placement. Five patients lost their implant within 24 months after insertion. The drop-out rate was 2 implants in 2 patients. The recall rate was thus 97%. Of the 5 implant failures, 2 were located in the maxilla and 3 in the mandible. The Kaplan-Meier survival probability was 93% after 120 months. 74% of the sites showed healthy peri-implant soft tissue conditions. At 15 implants (22%) a bone resorption of more than 2 mm was observed on intraoral radiographs. The mean bone resorption was 1.8 mm in the maxilla and 1.3 mm in the mandible and did not increase with time (Pearson correlation coefficient: r = -0.06, P = 0.59). Abutment loosening occurred in 7 implants (10%), however all abutments that were fixed with a defined torque subsequently remained stable. Thus the favourable preliminary results could be maintained over an average 66 months, indicating that if implant loss happens it seems to occur during the first 2 years after insertion.

Changes in the provision of implant-supported prostheses at the Academic Centre for Dentistry Amsterdam (ACTA) from 1989 to 1995

PURPOSE

Over the last decade, oral implantology has become a major treatment modality to aid the restoration of reduced dentitions. The present study monitored and quantified changes within a 5-year interval (1989-1991 [denoted as 1990*] to 1995) in the provision of different types of implant-supported superstructures and characteristics of recipient patients at the Academic Centre for Dentistry Amsterdam (ACTA).

MATERIALS AND METHODS

All patients who received oral implants in 1990* and in 1995 were selected, and their files (95 and 105, respectively) were consulted. Data of interest were retrieved retrospectively, compared, and statistically analyzed using Chi-squared tests.

RESULTS

A number of statistically significant differences was apparent between these 2 periods. By 1995 there was a threefold increase in both the number of patients and the number of implants placed per year. The patient group of < or = 40 years of age had significantly increased, from 7% to 23%. Also, in 1995 more maxillae were implanted than in 1990* (44% vs 26%). Whereas the majority of implanted patients was edentulous in 1990* (64%), the majority in 1995 was partially edentulous (60%). By 1995, the new technique of guided bone regeneration (GBR) using membranes was evidenced (no GBR in 1990* vs 33% of all patients in 1995 receiving some form of local GBR therapy). With respect to the type of superstructures, there was a strong increase in the number of single-tooth replacements (from 4% to 23%). In the edentulous group, the majority of superstructures in 1990 was fixed prostheses (64%), whereas in 1995 the majority was overdentures (71%).

CONCLUSION

Major changes in oral implantology treatments were noticed between the 1990* and 1995 periods at ACTA. There is a trend toward implanting younger patients for partial implant-supported reconstructions using more regenerative procedures and with a more equal distribution in the maxilla and mandible.

Osseointegrated Implant for Single-Tooth Replacement: A Retrospective Multicenter Study on Routine Use in Private Practice

BACKGROUND

Implant restorations first started with total edentulism. Later, the scientific community gave its approval for restorations in partial edentulism, and only recently some studies confirmed the validity of the treatment for single-tooth replacement.

PURPOSE

The purpose of the study was to evaluate implant survival and prosthesis stability of Brånemark implants (titanium screws) when used routinely for single-tooth replacement in all regions.

MATERIALS AND METHODS

Two hundred and fourteen patients received 252 implants for single-tooth replacement over a period of 8 years at five private clinics in Italy. The patients were treated in accordance with the protocol for Brånemark implants, and the data gathered have been analyzed according to established evaluation methods.

RESULTS

During the observation period, 10 failures were recorded and 229 restorations were carried out. After the first year of loading, the total cumulative survival rate (CSR) was 96%, which then remained stable over the study time. The most frequent complication was loosening of the abutment screws (n = 22), amounting to 35% of all of the complications. This problem was related mainly to earlier types of abutments, whereas the more recent design, CeraOne abutment, showed a low frequency of screw loosening.

CONCLUSIONS

The high survival rate, which is similar to that presented for prospective multicenter studies for single-tooth restorations with Brånemark implants, led to the conclusion that the use of this treatment modality is a reliable treatment for routine use in all oral regions.

Implant-supported single-tooth replacements: risk of implant and prosthesis failure

Data from 236 patient cases of implant-supported single-tooth replacements in the maxillary anterior region were sequentially recorded and documented. The time in situ ranged from a minimum of five to a maximum of 19 years. Twenty-two implants failed during the observation period. The causes of such failure were peri-implantitis, implant fracture, and trauma. The probability of success according to the Kaplan-Meier method decreased to 0.89 over a period of 10 years. The failure rate for implants replacing lateral incisors was lower than that for implants replacing central incisors. Seventy-six cases were clinically documented for 10 years or more. In 15 cases, replacement of the prosthetic superstructure was necessary during the 10-year period. The course of therapy and clinical follow-up care is described by a multi-state distribution.

Construction of a clinical implant performance scale for implant systems with overdentures with the Delphi method

STATEMENT OF PROBLEM

The success of an implant system is often judged on the survival rate of the separate implants. This does not give a complete view of the "real" success of a system. To make that possible the total clinical performance, surgical and prosthetic, has to be considered.

PURPOSE

This study aimed to set up a clinical performance scale for different implant systems retaining mandibular overdentures.

MATERIAL AND METHODS

All data regarding surgical and prosthetic complications incurred and treatment procedures needed after implant placement were collected from a group of 90 patients who were treated either with two root form implants connected with a bar and supporting a mandibular overdenture or with a transmandibular implant system that supported an overdenture. All items were scored into five categories on the scale, defined as the "clinical implant performance" scale. The Delphi method was applied to categorize each item. A panel of experts assessed the items.

RESULTS

After three rounds there was complete consensus between the experts for 65% of the items for the root form implant systems, and for 87% of the items at least five out of six experts gave the same score. For 55% of the items for the transmandibular implants systems there was complete consensus, and for 85% of the items at least five out of six experts scored in the same way.

CONCLUSIONS

The Delphi method provides a useful scale for evaluating the clinical performance of implant systems retaining mandibular overdentures. The presented scale makes it possible to compare the overall performance of different implant systems for overdentures.

Implant placement in prosthodontics practice: a five-year retrospective study

Dental implants have revolutionized dentistry in every aspect of treatment including surgery, restorative dentistry, and orthodontic treatment planning.

PURPOSE

This retrospective study analyzes the treatment of completely and partially edentulous patients in a prosthodontics practice and the Edmonton Implant Seminar.

MATERIAL AND METHODS

All implant surgery was performed by the prosthodontist. The majority of implants (336) were restored by the prosthodontist (71%). A total of 135 restorations were provided by 12 different general practitioners (29%) in a study group environment.

RESULTS

Of 471 implants that were placed, 453 (96.2%) integrated successfully. Treatment groups were divided into single implant restoration (19.3%), fixed partial dentures (51%), overdentures (12.3%), and mandibular fixed partial denture cantilever (17.6%). Retention of final prosthesis was 99.4%. Of 18 failures, four occurred between Stage I and II surgeries, 11 occurred between Stage II surgery and final impressions, and three occurred after placement of final restorations. All three restorative failures were single implants.

CONCLUSION

The results indicated that implant placement by a prosthodontist is comparable to the success of previous studies.

Types, uses, and evaluation of the plate-form implant

Plate-form blades have shown a high rate of success over their 25+ years of service. Contributing to their longevity is the design of the implant, which transfers the applied forces over a large area of bone. Three types of implants are being considered: (1) the Ramus Blade, designed for the body and ramus region of the mandible; (2) the Ramus Frame, designed for the totally edentulous mandible with moderate to severe bone atrophy; and (3) the single-tooth replacement, an implant for single or multiple tooth loss. Both 316-L stainless steel and titanium metal types have been used to fabricate each implant type. Blades are, in the author's opinion, the most universal of the implants used today, for they are utilized in so many variable bone widths and heights. Besides being in service for periods of up to 27 years, they are patient-acceptable in terms of comfort, function and minimal maintenance.

A review of educational developments with Brånemark osseointegrated oral implants in Australia and New Zealand 1992-1994. Part I: Treatment data for Australia and New Zealand

This review should be read in conjunction with the Teams Day Conference review of 1992. This data further emphasises the trend in implant restoration that was becoming apparent at that time. However, the degree to which single tooth implant restorations now dominate clinical implant treatment is unprecedented. There is clear evidence of a progressive increase also in segmental and full arch bridgework, but minimal increase in overdenture restorations. The data also indicates that for the first time the number of males treated was greatest and that the maxilla was more frequently restored. This latter feature is no doubt closely linked with the emphasis given to single tooth restorations. This data, fully supports the inclusion of implant restoration into general and specialist dental practice.