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.     

ITI种植体5年临床应用回顾性分析

目的回顾性研究ITI种植体5年来在我院的临床应用效果。方法对216例患者植入ITI种植体379颗,修复完成后6个月复诊,观察方法为X线检查和临床检查,采用Wheeler存留标准评估,用生存分析的寿命表法统计。结果种植体失败11颗,其中2颗在愈合期内,累计存留率达96.98%。结论采用ITI种植体对牙列缺失、牙列缺损患者进行修复治疗5年后,种植体存留率较高。     

A multicenter report on 1,022 consecutively placed ITI implants: a 7-year longitudinal study

The aim of this multicenter study was to evaluate cumulative success and survival rates of ITI implants after 7 years. A complete medical report was obtained for all 440 patients enrolled in this investigation, which involved 10 different private practices. The 1,022 consecutively placed implants were distributed between completely edentulous, partially edentulous, and single-tooth replacement cases. During the annual follow-up visit, each implant was examined both clinically and radiographically using predefined success criteria. The cumulative survival and success rates were calculated for all implants. Implant subgroups were defined according to the medical history of the patients or pooled according to various indications, locations, implant designs, or implant lengths. In each subgroup, the related cumulative success rate was statistically compared to the global cumulative success rate. Fifteen implants (1.4%) were regarded as early failures, and at the end of the follow-up, the global failure rate reached 6.6%; 30 implants (3%) were lost to follow-up. At 5 years, the cumulative survival rate was 95.4%; this declined to 92.2% at 7 years. The weakest success rates were observed for implants placed in older patients, periodontally treated patients, and completely edentulous arches. Conversely, cumulative success rates that were significantly above average were observed for patients between 40 and 60 years old without pathology, implants placed after bone regeneration, solid-screw implants, implants placed in edentulous spaces, and implants placed as single-tooth replacements. This investigation has demonstrated that in these 10 private practice settings, the success rate for ITI implants remained high for up to 5 years and declined slightly between 5 and 7 years. It should be noted that in later year intervals, a relatively small number of implants remained for the analysis of cumulative success rates.     

Long-term evaluation of submerged and nonsubmerged ITI solid-screw titanium implants: a 10-year life table analysis of 468 implants

Purpose

Submerged and nonsubmerged ITI solid-screw titanium implants were followed retrospectively from 1989 to 1993 and prospectively from 1994 on to analyze long-term prognosis in partially and fully edentulous patients.

Material and Methods

A total of 468 implants were consecutively inserted in 191 patients from 1989 to 1998. Two hundred twenty-eight successfully integrated fixed-restoration implants and 238 with removable restorations were restored following a healing period of 4 to 6 months (9 months in sinus floor elevation sites). From 1994 on all implants inserted were documented annually up to 9 years. During examination the clinical status of the implants was analyzed and evaluated according to predefined criteria of success and this allowed the calculation of 10-year cumulative survival and success rates for 468 implants.

Results

Two implants (0.43%) did not successfully integrate during the healing period, and 8 implants (1.7%) were classified as failures during follow-up (1 late failure under load, 7 with a progressive bone loss from 1 to 3 threads). Including 68 implants in subjects who dropped out (with a dropout rate of 14.4%), the 10-year cumulative survival and success rates were 99.2% and 96.4%, respectively.

Discussion

Over the course of this long-term study, osseointegrated implants, once used as a last possible solution, became nearly standard in cases of single-tooth implants because of the high rate of long-term success. Life table analysis not only determines whether an implant is functioning, it also makes a statement about its clinical status according to strict success criteria.

Conclusion

The study demonstrated that ITI solid-screw titanium implants achieved success rates above 95% in a clinical center for an observation period of up to 10 years.—Reprinted with permission of Quintessence Publishing.     

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.     

Long-term evaluation of submerged and nonsubmerged ITI solid-screw titanium implants: a 10-year life table analysis of 468 implants

PURPOSE: Submerged and nonsubmerged ITI solid-screw titanium implants were followed retrospectively from 1989 to 1993 and prospectively from 1994 on to analyze long-term prognosis in partially and fully edentulous patients. MATERIAL AND METHODS: A total of 468 implants were consecutively inserted in 191 patients from 1989 to 1998. Two hundred twenty-eight successfully integrated fixed-restoration implants and 238 with removable restorations were restored following a healing period of 4 to 6 months (9 months in sinus floor elevation sites). From 1994 on all implants inserted were documented annually up to 9 years. During examination the clinical status of the implants was analyzed and evaluated according to predefined criteria of success and this allowed the calculation of 10-year cumulative survival and success rates for 468 implants. RESULTS: Two implants (0.43%) did not successfully integrate during the healing period, and 8 implants (1.7%) were classified as failures during follow-up (1 late failure under load, 7 with a progressive bone loss from 1 to 3 threads). Including 68 implants in subjects who dropped out (with a dropout rate of 14.4%), the 10-year cumulative survival and success rates were 99.2% and 96.4%, respectively. DISCUSSION: Over the course of this long-term study, osseointegrated implants, once used as a last possible solution, became nearly standard in cases of single-tooth implants because of the high rate of long-term success. Life table analysis not only determines whether an implant is functioning, it also makes a statement about its clinical status according to strict success criteria. CONCLUSION: The study demonstrated that ITI solid-screw titanium implants achieved success rates above 95% in a clinical center for an observation period of up to 10 years.     

A 5-year retrospective clinical study of the Dentium implants

PURPOSE

The aim of this retrospective study was to evaluate cumulative survival rate (CSR) of Implantium implants followed for 5 years and association between risk factors and the CSR.

MATERIALS AND METHODS

A total of two hundred forty-nine Implantium Implants System (Dentium, Seoul, Korea) placed in ninety-five patients from 2004 to 2009 were investigated with several identified risk factors (sex, systemic disease, smoking, alchohol, reason of tooth loss, length, arch (maxilla or mandible), replace tooth type (incisor, canine, premolar or molar) Kennedy classification, prosthodontic type, prosthodontic design, opposite dentition, abutment type, occlusal material, occlusal unit, splint to tooth, cantilever, other surgery). Clinical examination (mobility, percussion, screw loosening, discomfort, etc.) and radiographic examination data were collected from patient records including all problems during follow-up period according to protocols described earlier. Life table analysis was undertaken to examine the CSR. Cox regression method was conducted to assess the association between potential risk factors and overall CSR.

RESULTS

Five of 249 implants were failed. Four of these were lost before loading. The 5-year implant cumulative survival rate was 97.37%. Cox regression analysis demonstrated a significant predictive association between overall CSR and systemic disease, smoking, reason of tooth loss, arch, Kennedy classification and prosthodontic design (P<.05). The screw related complication was rare. Two abutment screw fractures were found. Another complications of prosthetic components were porcelain fracture, resin facing fracture and denture fracture (n=19).

CONCLUSION

The 5-year CSR of Implantium implants was 97.37%. Implant survival may be dependent upon systemic disease, smoking reason of tooth loss, arch, Kennedy classification and prosthodontic design (P<.05). The presence of systemic diseases and combination of other surgical procedures may be associated with increased implant failure.     

Tissue integration of one-stage ITI implants: 3-year results of a longitudinal study with Hollow-Cylinder and Hollow-Screw implants.

This study examined the tissue integration of one-stage, nonsubmerged ITI implants over a period of 3 years. Fifty-four implants were placed in 38 partially edentulous patients. Following healing (at least 3 months), all 54 implants were free of peri-implant infections and revealed no detectable mobility. Radiographs showed no signs of peri-implant radiolucencies, and the implants were in favorable positions for prosthetic restoration. Following incorporation of fixed partial dentures, patients were enrolled in a hygiene recall program with 3-month intervals and were examined once a year. Based on predefined criteria, each implant was classified as successful or failing. After the 3-year observation period, 51 of 53 implants (96.2%) were considered successfully integrated. (One patient with one implant dropped out of the study.) Two implants exhibited recurrent peri-implant infections and were classified as late failures. These results indicate that one-stage ITI implants can achieve successful tissue integration on a predictable basis and that it can be maintained over a period of at least 3 years.     

Periotest® measurements and osseointegration of mandibular ITI implants supporting overdentures. A one‐year longitudinal study.

The Periotest values of mandibular implants, registered before and after loading by overdentures, were compared. Thirty edentulous patients with 60 Bonefit ITI implants were selected with an average age of 69 years. The Periotest values were measured 1) after a healing period of 3 months and 2) after the overdentures had been worn for a period of 12 months. Periodontal parameters were recorded at both examinations. Furthermore, 17 biopsies of mandibular bone taken from the implant sites during implant surgery were analyzed to assess the bone density. The histomorphometric evaluation was done using a point count method. At the end of the healing period. all registered Periotest values were negative, ranging from −1 to −8 with an average of 4.08. One year later, all measurements showed negative values again, ranging from −2 to −8 with an average of 4.97. The difference was statistically significant. Seventeen biopsies of mandibular bone were evaluated to determine the density. The range of bone density was from 22.4% and 90.9%. There was no correlation found between bone density and Periotest values. However, a significant correlation could be observed between mandibular atrophy and bone density.     

Immediate loading of single-tooth ITI implants in the anterior maxilla: a prospective 5-year pilot study

The aim of the present study was to evaluate the success rate of immediately loaded single-tooth ITI solid plasma-sprayed (TPS) implants in the maxilla. Eight implants were loaded immediately after placement in eight different patients, and were followed for five years. Temporary acrylic resin restorations, which were fabricated from impressions that were taken immediately after implant placement, were connected one week later. These temporary restorations were adjusted in order to avoid any direct occlusive contacts. After six months, the provisional crowns were replaced by definitive ceramic crowns. Regular follow-ups were performed during the investigation period. No implants were lost, and the mean marginal bone level for the eight implants increased by 0.53 mm (range - 0.83 to + 1.54 mm) from placement to the final examination. Only minor complications were noted, and overall patient satisfaction was high.     

Implant-supported fixed prostheses in the edentulous maxilla. A 2-year clinical and radiological follow-up of treatment with non-submerged ITI implants

OBJECTIVES: To evaluate the survival rate of non-submerged solid-screw ITI dental implants with a rough (titanium plasma sprayed, TPS) surface in the edentulous maxilla after 1 and 2 years of loading. MATERIAL AND METHOD: Twenty-five patients (mean age 64 years) with edentulous upper jaws received five-seven implants and, after a mean healing time of 6.9 months, screw-retained implant-supported fixed prostheses. A total of 146 ITI solid screw TPS implants were inserted. The diameter of 56% of the implants was smaller (3.3 mm) than the standard (4.1 mm) and the diameter of the rest (44%) was standard. The bone quantity of the majority of the patients was low and the bone quality poor. Clinical parameters were registered at baseline and at two annual follow-ups. Radiological examinations and assessments were also made at these times. RESULTS: Mean marginal bone level at baseline was measured at a point 4.52 mm (range 1.45-7.70, SD 1.2) apical of the reference point. Mean bone loss from baseline to 1 year of loading was 0.24 mm (SD 0.9, P=0.002) and from 1 year to 2 years of loading 0.15 mm (SD 0.4, P<0.001). Five implants failed, four of which were early failures prior to loading. One implant failed shortly after bridge installation. The cumulative survival rate was 96.6% after 1 and 2 years. CONCLUSION: ITI TPS solid-screw implants in combination with fixed prostheses had successful survival rates and were found to be a viable treatment alternative in the edentulous maxilla.     

A 5-year prospective clinical and radiographic study of non-submerged dental implants

Osseointegrated implants as anchors for various prosthetic reconstructions have become a predictable treatment alternative. It was expected that implants required submucosal placement during the healing period for successful tissue integration. However, it has been demonstrated that healing and long-term health of implants could be achieved with equal predictability in a 1-stage, non-submerged approach. This prospective 5-year study not only calculates implant success by life table analysis, but also evaluates the correlation between observed bone level changes with clinical parameters as measured by suppuration, plaque indices, bleeding indices, probing depth, attachment level and mobility. A total of 112 ITI dental implants were inserted in different areas of the jaws. Clinical and radiographic parameters were evaluated annually for 5 years, whereas a portion of the study group for which 6-year evaluations were available were included in the life-table analysis. The overall success rate after 5 years in service was 99.1%, while after 6 years it was reduced to 95.5% due to the fracture of 3 implants in 1 patient. The mean crestal bone loss experienced during the first year was 0.6 mm followed by an annual yearly loss of approximately 0.05 mm. No significant differences could be found between the amount of bone loss measured at each of the yearly follow-up visits. This suggests that statistically the followed implants did not show any radiographically measurable bone loss following the initial period of bone loss associated with implant placement and osseointegration. Low levels of correlation between the individual and cumulative clinical parameters with radiographically measured bone loss suggests that these parameters are of limited clinical value in assessing and predicting future peri-implant bone loss.     

Implant-retained mandibular overdentures with immediate loading: a prospective study of ITI implants

A prospective study was conducted in which 21 patients received a mandibular implant-supported overdenture. Eighty-four ITI screw-type implants were placed in the interforaminal area of the mental symphysis (4 implants per patient). Immediately after implant placement, a U-shaped gold or titanium bar was fabricated and implants were loaded with an implant-retained overdenture. Of 21 patients treated, 19 were followed for a minimum of 25 months to a maximum of 60 months, with a mean follow-up of 37 months. Two patients dropped out during the follow-up. The overall failure rate of implants (according to Albrektsson criteria) was 4% (3/76 implants), but all implants, bars, and prostheses remained in function. Results from this study demonstrated that the success rate for immediately loaded mandibular implants is similar to that obtained in cases of delayed loading, after osseointegration has taken place. This method shortens dental rehabilitation time with relevant satisfaction for patients.     

A clinical 5-year longitudinal study on the dimensional changes of complete maxillary dentures

PURPOSE: Acrylic resin complete dentures exhibit dimensional changes mainly because of processing shrinkage and expansion because of water uptake. The aim of this 5-year clinical study was to determine the dimensional changes occurring during construction and in service in maxillary complete dentures made of two types of acrylic resin. MATERIALS AND METHODS: Complete dentures were constructed for 17 edentulous patients. Nine patients received dentures made of conventional heat-cured acrylic resin, and eight patients received dentures made of rapid heat-cured acrylic resin. Measurements were taken across three reference points (second molars bilaterally and central incisors) on six occasions: at the flasking stage, at the denture insertion appointment, and after 1 week, 1 month, 3 months, and 5 years of use. The data obtained were analyzed using one-factor repeated-measures ANOVA, one-way ANOVA, and Duncan's multiple comparisons test. RESULTS: The two types of dentures showed the same pattern of dimensional changes. A shrinkage of up to 0.27% was estimated at the insertion stage. During the first 3 months of use, a decrease of the initial dimensional change was observed. After a 3-month period, a gradual compensation for the initial shrinkage started to take place. At the end of the study period (5 years), an expansion of up to 0.35% was measured. CONCLUSION: Maxillary complete dentures made of either conventional or rapid heat-cured acrylic resin exhibited dimensional changes that were considered clinically acceptable.     

Short (8-mm) dental implants in the rehabilitation of partial and complete edentulism: a 3- to 14-year longitudinal study

PURPOSE: This study aimed to evaluate the clinical effectiveness of different implant sizes (8- and 10-mm lengths with 3.75-, 4.1-, and 4.8-mm diameters) in diverse host bone sites in a selected sample of partially and completely edentulous patients. MATERIALS AND METHODS: Over a 14-year period, 129 patients (68 women and 61 men) were consecutively treated with a fixed prosthesis (single or multiunit, screw or cement retained) supported by 265 different-sized implants (154 standard 10-mm; 111 shorter 8-mm). Two types of implants were used (141 titanium plasma-sprayed and 124 Sand-blasted, large-grit, acid-etched). RESULTS: Dropouts were recorded for 23 patients with 23 prostheses supported by 42 implants. In the remaining 106 patients (223 implants), 8 implants failed (4 standard and 4 shorter), in type 3 or 4 bone. Mean marginal bone loss and gingival crevice probing depth associated with either implant length were statistically comparable (P> .05). The 14-year cumulative survival rates for all short and standard implants were 97.9% and 97.1%, respectively. Survival rates were 92.3% and 95.9% for titanium plasma-sprayed short and standard implants, respectively, and 100% and 98.5% for the Sand-blasted, large-grit, acid-etched short and standard implants, respectively. Six of the 8 lost implants required implant replacement after the host sites' healing period. The remaining 2 lost implants were managed by converting the distal unit of the fixed partial prosthesis to a cantilever. CONCLUSION: Within the limits of the study design and observation period, a mix of implant sizes did not appear to compromise the effectiveness of implant therapy in this particular population group.     

Conventional and early loading of unsplinted ITI implants supporting mandibular overdentures

The aim of this study was to compare the success rates after 1 and 2 years of conventionally and early loaded pairs of unsplinted ITI implants supporting mandibular overdentures in edentulous patients. Twenty-four participants (age range 55-80 years) were randomly allocated with maximum concealment to two treatment groups. In the first group, the implants were allowed to heal for 12 weeks before being functionally loaded (control) and the second group had 6 weeks of healing with identical loading. All participants had new conventional complete maxillary and mandibular dentures prior to the study. Two sandblasted large-grit acid-etched (SLA) surface ITI implants were placed in the mandibular interforaminal area, following a standardized nonsubmerged surgical protocol. After 6 or 12 weeks of healing, matrices were processed into the fitting surface of the pre-existing mandibular dentures and the implants loaded. Implant success was determined using mobility tests and radiographs taken at baseline and 52 and 104 weeks after surgery. Clinical peri-implant parameters were also documented. Results showed all implants successfully osseointegrated, according to accepted criteria, after 2 years. Mean loss of crestal bone height after 1 year was 0.35 +/- 0.22 mm (control) vs. 0.27 +/- 0.18 mm (test). After 2 years this reduced to 0.09 +/- 0.06 mm (control) vs. 0.12 +/- 0.17 mm (test). The mean Periotest value after 1 year was -4.9 (control) vs.-3.78 (test). After 2 years, the mean resonance frequency value for the control implants was 6797 Hz [mean implant stability quotient (ISQ) = 64.77] and for the test implants 6670 Hz (mean ISQ = 62.0). Shortened loading periods for these ITI implants did not cause any statistically significant differences in osseointegration or peri-implant parameters. We conclude that pairs of unsplinted SLA-surface ITI implants can be successfully loaded with mandibular overdentures 6 weeks after surgery.     

A six-year prosthodontic study of 509 consecutively inserted implants for the treatment of partial edentulism.

A total of 509 consecutive Br?nemark TM implants (Nobelpharma AB, Gothenburg, Sweden) were inserted in 146 patients between December 1982 and May 1989, on which 217 fixed partial dentures were planned. The cumulative failure rates after abutment connection were 3.9% and 4.1% for the maxillae and mandible, respectively. The lack of continuous prosthesis stability was limited to 4.1% for the maxillae and 5.4% for the mandible. The average annual marginal bone loss was 0.77 mm (SD = 1.0) and 0.96 mm (SD = 0.9) for the maxillae and mandible, respectively, during the first year and averaged 0.1 mm for the following years. The mode of connection between teeth and implants or the use of porcelain instead of composite resin as occlusal material did not influence the marginal bone height around the implants. Technical complications were most often related to the materials used. The results of a medium-term follow-up encourage the use of the Br?nemark osseointegration system in the treatment of partial edentulism.