Early loading of non-submerged titanium implants with a sandblasted and acid-etched surface. 5-year results of a prospective study in partially edentulous patients

OBJECTIVES: The aim of this prospective cohort study was to evaluate the success rate of titanium screw-type implants with the sandblasted and acid-etched (SLA) surface loaded early, after 6 weeks of healing. MATERIAL AND METHODS: A total of 104 implants were inserted into posterior sites of 51 partially edentulous patients exhibiting bone densities of class I-III. After a healing period of 6 weeks, all implants were functionally loaded with cemented crowns or fixed partial dentures. The patients were recalled at 3, 12, 24, 36, 48 and 60 months for clinical and radiographic examination. RESULTS: One implant failed to integrate during healing, and three implants were lost to follow-up and were considered drop-outs. The remaining 100 implants showed favorable clinical and radiographic findings at the 5-year examination. The peri-implant soft tissues were stable over time; the mean probing depths and mean attachment levels did not change during the follow-up period. None of the radiographs exhibited signs of continuous peri-implant radiolucency, which confirmed ankylotic stability for all 100 implants. The measurement of the bone crest levels (DIB values) indicated stability as well. Based on strict success criteria, all 100 implants were considered successfully integrated, resulting in a 5-year success rate of 99%. CONCLUSION: This prospective study using an early loading protocol with 6 weeks of healing demonstrated that titanium implants with the SLA surface can achieve and maintain successful tissue integration with high predictability for at least 5 years of follow-up in selected patients and sites.     

Mucosal and radiographic aspects during the healing period of implants placed in a one-stage procedure

PURPOSE: The aim of this prospective clinical trial was to compare peri-implant clinical and radiographic parameters following the placement of nonsubmerged two- and one-stage implants. MATERIALS AND METHODS: Patients were randomly assigned to the IMZ group (20 patients receiving two IMZ two-stage implants in a one-stage procedure) or ITI group (20 patients receiving two ITI implants in the conventional one-stage procedure). The healing period was defined as an 18-week unloaded osseointegration period and a 1-year functional period during which maturation of bone took place. Twelve weeks after implant placement, fabrication of an overdenture with a bar-clip attachment system was started; it was placed at 18 weeks. RESULTS: None of the implants were lost during the osseointegration period; one IMZ implant was removed during the functional period because of mobility. There was no significant difference in Gingival Index between the two groups at all evaluation periods. The mean bone loss during the functional period was 0.6 mm in both groups. A high number of healing abutments loosened in the IMZ group. CONCLUSION: Clinical and radiographic parameters of two-stage implants placed in a one-stage procedure and one-stage implants are comparable during the healing period. Healing abutments of the IMZ implant system loosen easily.     

Clinical performance of wide-body implants with a sandblasted and acid-etched (SLA) surface: results of a 3-year follow-up study in a referral clinic

PURPOSE: The aim of this study was to evaluate the 3-year success rates of wide-body implants with a regular- or wide-neck configuration and a sandblasted, large grit, acid-etched (SLA) surface. MATERIALS AND METHODS: A total of 151 implants were consecutively placed in posterior sites of 116 partially edentulous patients in a referral clinic at the School of Dental Medicine, University of Bern. All implants were restored with cemented crowns or fixed partial dentures after a healing period of 6 to 8 weeks (for implants placed without simultaneous bone augmentation) or 10 to 14 weeks (for implants with simultaneous bone augmentation). All patients were recalled 36 months following implant placement for a clinical and radiographic examination. RESULTS: One implant failed to integrate during healing, and 11 implants were lost to follow-up and considered dropouts. The remaining 139 implants showed favorable clinical and radiographic findings and were considered successfully integrated at the 3-year examination. This resulted in a 3-year success rate of 99.3%. Radiographic evaluation of 134 implants indicated stability of the crestal bone levels: During the study period, the crestal bone level changed less than 0.5 mm for 129 implants. CONCLUSION: Successful tissue integration was achieved with wide-body implants with a regular or a wide-neck configuration and an SLA surface with high predictability. This successful tissue integration was well maintained for up to 3 years of follow-up.     

Early Loading of Nonsubmerged Titanium Implants with a Chemically Modified Sand-Blasted and Acid-Etched Surface: 6-Month Results of a Prospective Case Series Study in the Posterior Mandible Focusing on Peri-Implant Crestal Bone Changes and Implant Stability Quotient (ISQ) Values

Purpose: The aim of this prospective case series study was to evaluate the short-term success rates of titanium screw-type implants with a chemically modified sand-blasted and acid-etched (mod SLA) surface after 3 weeks of healing.
Material and Methods: A total of 56 implants were inserted in the posterior mandible of 40 partially edentulous patients exhibiting bone densities of class I to III. After a healing period of 3 weeks, all implants were functionally loaded with a screw-retained crown or fixed dental prosthesis. The patients were recalled at weeks 4, 7, 12, and 26 for monitoring and assessment of clinical and radiological parameters, including implant stability quotient (ISQ) measurements.
Results: None of the implants failed to integrate. However, two implants were considered "spinners" at day 21 and left unloaded for an extended period. Therefore, 96.4% of the inserted implants were loaded according to the protocol tested. All 56 implants including the "spinners" showed favorable clinical and radiographic findings at the 6-month follow-up examination. The ISQ values increased steadily throughout the follow-up period. At the time of implant placement, the range of ISQ values exhibited a mean of 74.33, and by week 26, a mean value of 83.82 was recorded. Based on strict criteria, all 56 implants were considered successfully integrated, resulting in a 6-month survival and success rate of 100.0%.
Conclusion: This prospective study using an early-loading protocol after 3 weeks of healing demonstrated that titanium implants with the modified SLA surface can achieve and maintain successful tissue integration over a period of at least 6 months. The ISQ method seems feasible to monitor implant stability during the initial wound-healing period.     

Is the osseointegration of immediately and delayed loaded implants the same?—comparison of the implant stability during a 3‐month healing period in a prospective study

Objectives: The objectives of the present study were (1) to compare the stability of delayed loaded (DL) and immediately loaded (IL) ITI SLA implants during the first 3 months of the healing period using resonance frequency analysis (RFA) and (2) to determine the factors that affect implant stability during the healing period.
Materials and methods: To compare implant stability, RFA was performed on two groups of patients (12 patients received 25 IL implants and 47 patients received 79 DL implants) with a total 104 ITI SLA implants. Implant stability was measured directly by RFA at implant placement and consecutively once a week for 12 weeks. Statistical analyses were carried out to study implant stability differences between IL and DL groups.
Results: One of the 25 implants in the IL group failed, and no implant was lost in the DL group. Implant stability between the IL and DL groups showed a statistically significant difference ( P <0.05). The mean implant stability quotient of all measured implants from implant insertion to 12 weeks was 72.88 ± 5.39 for the DL and 75.86 ± 3.60 for the IL types. The lowest stability was at 4 weeks for DL implants (mean: 71.58 ± 5.11) and 2 weeks for IL implants (mean: 71.33 ± 2.97). In both groups, bone types I and II showed higher implant stability than bone type III ( P <0.05).
Conclusions: The findings of this study indicate that differences in osseointegration between IL and DL implants may be predicted according to differential implant stability.     

The use of reduced healing times on ITI implants with a sandblasted and acid-etched (SLA) surface: early results from clinical trials on ITI SLA implants

ITI dental implants are available with two bone-anchoring surfaces, a titanium plasma-sprayed (TPS) surface, and a recently introduced sandblasted and acid-etched (SLA) surface. Cell culture and animal tests demonstrate that the SLA surface stimulates bone cell differentiation and protein production, has large amounts of bone-to-implant contact, and results in large removal torque values in functional testing of the bone contact. As a result of these studies, a prospective human clinical trial was initiated to determine whether the 4.1 mm diameter SLA ITI solid screw implants could be predictably and safely restored as early as six weeks after implant placement surgery. The protocol restricted the use of the reduced healing time to a) healthy patients with sufficient bone volume to surround the implant, and b) those patients who had good bone quality (classes I-III) at the implant recipient site. Patients with poorer bone quality (class IV) did not have restorations until 12 weeks after implant placement. The clinical trial is an ongoing multicenter trial, with six centers in four countries, and with follow-up over five years. The primary outcome variable was abutment placement with a 35 Ncm force, with no countertorque and no pain or rotation of the implant. A secondary outcome was implant success, as defined by no mobility, no persistent pain or infection, and no peri-implant radiolucency. To date, 110 patients with 326 implants have completed the one-year post-loading recall visit, while 47 patients with 138 implants have completed the two-year recall. Three implants were lost prior to abutment connection. Prosthetic restoration was commenced after shortened healing times on 307 implants. The success rate for these implants, as judged by abutment placement, was 99.3% (with an average healing time of 49 days). Life table analyses demonstrated an implant success rate of 99.1%, both for 329 implants at one year and for 138 implants at two years. In the 24-month period after restoration, no implant losses were reported for the 138 implants. These results demonstrate that, under defined conditions, solid screw ITI implants with an SLA endosseous surface can be restored after approximately six weeks of healing with a high predictability of success, defined by abutment placement at 35 Ncm without countertorque, and with subsequent implant success rates of greater than 99% two years after restoration.     

Immediately loaded implants supporting fixed prostheses in the edentulous maxilla: a preliminary clinical and radiologic report

PURPOSE: To evaluate the survival rate of immediately loaded ITI sand-blasted, large-grit, acid-etched (SLA) solid-screw dental implants in the edentulous maxilla after 8 months of loading. MATERIALS AND METHODS: Twenty-eight patients (mean age 63 years) with edentulous maxillae each received 6 implants and 1 implant-supported fixed provisional prosthesis within 24 hours after surgery. After a mean healing time of 15 weeks, the patient received a definitive, screw-retained, implant-supported fixed prosthesis. A total of 168 implants were placed. Clinical parameters were registered after 1 month of loading with the implant-supported fixed prostheses as well as 8 months after implant placement. Radiologic examinations and assessments were made at implant placement and after 8 months. RESULTS: The mean marginal bone level at implant placement was 1.6 mm (range 0 to 5.1; SD 1.1) apical of the reference point (the implant shoulder). The mean marginal bone level at the 8-month follow-up was 3.2 mm (range 0.4 to 5.9; SD 1.1) apical of the reference point. Three implants failed during the healing period. DISCUSSION: The improved results in the present study might be a result of the positive effect of splinting the implants immediately after placement. CONCLUSION: ITI SLA solid-screw implants immediately loaded (ie, loaded within 24 hours of placement) and supporting fixed prostheses had successful survival rates after 8 months. The present results constitute a solid baseline for future follow-up studies.     

Maxillary sinus floor augmention with autogenous bone grafts to enable placement of SLA-surfaced implants: preliminary results after 15-40 months

This study presents preliminary results of placing SLA(R) surfaced ITI(R) implants in conjunction with maxillary sinus floor augmentations using autogenous bone. One hundred and eighty three ITI implants (SLA(R) surface) were inserted after 66 sinus floor elevation procedures in 41 consecutive patients. Forty-eight implants were placed simultaneously and 135 implants in a staged procedure with an average healing time of 4.9 months (148 days) after sinus grafting. Loading of the implants was allowed following an average time of 4.1 months (122 days). The follow-up time was 15-40 months after implant placement. Clinical follow-up consisted of single tooth and panoramic X-rays, and determination of Bleeding On Probing (BOP) and Plaque Index. One implant failed. One hundred and eleven of the inserted implants were used for fixed dentures, 20 for bar constructions, 41 for single crowns, and 11 were loaded provisionally until today. The total 2-year implant survival rate was 99.5%. Keeping the short follow-up period in mind, the encouraging results compared with previous studies, further support the findings of a positive influence of rough surfaces in grafted bone.     

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.     

Immediate loading of implants with 3-unit fixed partial dentures: a 12-month clinical study

PURPOSE: The aim of the present clinical trial was to evaluate the 12-month success rate of titanium dental implants placed in the posterior mandible and immediately loaded with 3-unit fixed partial dentures. MATERIALS AND METHODS: Patients with missing mandibular premolars and molars were enrolled in this study. To be included in the study, the implants had to show good primary stability. Implant stability was measured with resonance frequency analysis using the Osstell device (Integration Diagnostics). Implants were included in the study when the stability quotient (ISQ) exceeded 62. Clinical measurements, such as width of keratinized tissue, ISQ, and radiographic assessment of peri-implant bone crest levels, were performed at baseline and at the 12-month follow-up. The comparison between the baseline and the 12-month visits was performed with the Student t test for paired data (statistically significant at a level of alpha = 0.05). RESULTS: Forty implants with a sandblasted, large grit, acid-etched (SLA) surface (Straumann) were placed in 20 patients. At 12 months, only 1 implant had been lost because of an acute infection. The remaining 39 implants were successful, resulting in a 1-year success rate of 97.5%. Neither peri-implant bone levels, measured radiographically, nor implant stability changed significantly from baseline to the 12-month follow-up (P > .05). DISCUSSION: The immediate functional loading of implants placed in this case series study resulted in a satisfactory success rate. CONCLUSION: The findings from this clinical study showed that the placement of SLA transmucosal implants in the mandibular area and their immediate loading with 3-unit fixed partial dentures may be a safe and successful procedure.     

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.     

Early loading (2 or 6 weeks) of sandblasted and acid-etched (SLA) ITI implants in the posterior mandible. A 1-year randomized controlled clinical trial

The aim of this 1-year prospective controlled clinical trial was to evaluate the effect of early loading of ITI solid screw titanium implants with a sandblasted and acid-etched (SLA) surface on clinical and radiographic parameters. MATERIAL AND METHODS: Twenty-seven consecutively admitted patients presenting bilateral edentulous posterior mandibular areas and in need of prosthetic reconstruction were recruited. Sixty-seven ITI standard solid screw implants with an SLA surface, a diameter of 4.1 mm and a length of 8, 10 or 12 mm were installed bilaterally in molar and premolar areas according to a one-stage surgical protocol. One week (test) and 5 weeks (control) after implant placement, solid ITI prosthetic abutments were connected using a torque of 35 N cm. No provisional restoration was fabricated. Two weeks (test) and 6 weeks (control) after implant placement, porcelain-fused-to-metal single-tooth crowns were cemented. Clinical measurements were obtained at day 0 and 2, 6, 12, 24 and 52 weeks thereafter. Periapical radiographs were taken immediately after implant placement, after 6 weeks and at the 1-year examination. RESULTS: After 1 year, implant survival was 100%. Two test and one control implants rotated at the time of abutment connection and were left unloaded for 12 additional weeks. At the 1-year examination, no statistically significant differences were found between the test and control sites with respect to pocket probing depths (2.6 mm +/- 0.5 vs. 2.7 mm +/- 0.5), mean clinical attachment levels (3.1 mm +/- 0.4 vs. 3.2 mm +/- 0.5), mean percentages of sites bleeding on probing (9.7% vs. 8.3%), mean widths of keratinized mucosa (1.8 mm +/- 0.4 vs. 1.9 mm +/- 0.5), mean PerioTest values (-1.4 PTV +/- 0.9 vs. -1.6 PTV +/- 0.8) or mean crestal bone loss measurements (0.57 mm +/- 0.49 vs. 0.72 mm +/- 0.50). CONCLUSION: Based on these results, loading of titanium implants with an SLA surface as early as 2 weeks did not appear to jeopardize the osseointegration healing process in the posterior mandible. Furthermore, implants rotating at 35 N cm, if left unloaded for additional 12 weeks, did not negatively affect clinical and radiographic outcomes.     

Mandibular overdentures supported by two Brånemark, IMZ or ITI implants: a 5-year prospective study

OBJECTIVES: The aim of this prospective comparative study was to evaluate the survival rate and the condition of the peri-implant tissues of the IMZ implant system (two-stage cylindertype), the Br?nemark implant system (two-stage screwtype) and the ITI implant system (one-stage screwtype) supporting a mandibular overdenture during a 5-year follow-up period. MATERIAL AND METHODS: Three groups of 30 edentulous patients were treated with two endosseous implants in the interforaminal region of the mandible. Clinical and radiographic parameters were evaluated immediately after completion of the prosthetic treatment and after 1, 2, 3, 4 and 5 years of functional loading. RESULTS: The five-year survival rate is 98.3% for the IMZ group, 98.3% for the Br? group and 100% for the ITI group. Mean scores on indices for plaque, calculus, gingiva and bleeding were very low at all evaluation periods. Mean marginal bone loss over a period of 5 years, was 1.4 mm for the IMZ group, 0.7 mm for the Br? group and 0.9 mm for the ITI group. CONCLUSION: It is concluded that two implants placed in the interforaminal region, connected with a bar, supply a proper base for the support of a mandibular overdenture in the edentulous patient. After 5 years no clinically relevant and statistically significant radiographic changes had developed between the three implant systems.     

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.     

Implant-retained mandibular overdentures with ITI implants

This prospective study has been designed to compare the results of immediate and delayed loading of implant-retained mandibular overdentures after a 2-year follow-up. Twenty patients have been randomly divided into two groups. Group 1 patients (test group) received four ITI implants in the intraforaminal area of the mandible. Octa abutments were immediately screwed on implants; 2 days after surgery, the implants were rigidly connected with a U-shaped Dolder gold bar and loaded with an overdenture. Group 2 patients (control group) received, in the same area, the same type and number of implants, which were left to heal according to the standard protocol. At 3-4 months, Octa abutments were screwed on the implants and the same prosthetic procedure of the test group was applied. The minimum follow-up period lasted 2 years, with recall appointments at 2 weeks, 1, 3, 6 months, 1 year and every following year postoperatively, evaluating: MPI, MBI, PD, Periotest and radiographic peri-implant bone resorption. Success criteria according to Albrektsson et al. were used. Only one implant out of the 40 of group 2 failed, whereas none failed in group 1. No statistical difference of the clinical parameters evaluated was noticed in the two groups. Therefore, immediate loading of implants, if connected with a U-shaped bar, can provide the same results of the 'traditional' technique as far as osseointegration and short-term survival rates of implants are concerned. Moreover, this method significantly shortens the treatment period, thus increasing patient satisfaction.     

Long-term evaluation of sandblasted and acid-etched implants used as orthodontic anchors in dogs.

The aim of this study was the clinical, radiographic, and histologic evaluation of the tissue surrounding SLA (sandblasted and acid-etched) implants loaded with a continuous and constant force for 52 weeks, after a healing period of 6 weeks, after implant insertion. SLA implants were placed in the maxilla of 3 dogs and the mandible of 5 dogs after a 12-week healing period after extraction. Abutments were attached to the 6 test implants (2 in the maxilla, 4 in the mandible). Superelastic nickel-titanium coil springs were activated between the SLA implants and the canines, producing a force of 200 g (2 N). Two unloaded implants (1 in the maxilla, 1 in the mandible) served as controls. Histologic analysis showed a corticalization of bone trabeculae, thicker at the loaded than at the unloaded implants. New bone formation at the level of the crest was slightly superior in the test implants. A difference between the tension and compression areas could not be observed in the test implants. The mean bone-implant contact values of the test implants for the maxilla and mandible were 40.23% and 49.33%, respectively. In the control implants, the bone-implant contact value was 67.91% for the maxilla and 49.23% for the mandible. SLA implants can be used as an anchorage unit with confidence, in spite of a short healing period and a prolonged force application. Further studies with different force magnitudes and healing periods are required to clarify the effects of healing period and force magnitude on bone quality and quantity.     

愈合期埋植型和非埋植型种植体周围牙槽骨吸收情况观察

目的：观察比较愈合期两段式埋植型和非埋植型种植体周围牙槽骨吸收情况是否存在差异。方法：收集种植义齿修复下颌后牙区牙体缺损患者44例共94颗,其中54颗两段式埋植型Frialit-2种植体和40颗两段式非埋植型ITI种植体,根据种植体植入术后和愈合后数字化全景X线片来进行种植体周围牙槽骨高度的测量。结果：显示愈合期两段式埋植型Frialit-2种植体和非埋植型ITI种植体周围骨吸收值不存在统计学差异（p=0．667〉0．05）。结论：在本实验条件下,愈合期埋植型和非埋植型种植体周围牙槽骨骨吸收改变与种植体的植入方式无关。     

ITI种植体早期负重与传统负重稳定性的比较

目的：应用共振频率分析评价早期负重种植体的稳定性,为种植体早期负重的可行性提供客观依据。方法：50例牙列缺损患者共植入104颗ITISLA表面实心螺纹种植体,随机分为2组,实验组为早期负重组,于术后6周修复;对照组为无负重组,于术后12周修复。在种植体植入术后当天、1周、4周、6周、8周、12周使用无线共振频率分析仪（Osstell Mentor）测定2组种植体的稳定性,所得参数为种植体稳定值（ISO）。采用Minitab统计软件对数据进行t检验．得出各时段2组ISQ值的P值。结果：术后12周,2组种植体的留存率均为100％,2组种植体在各时间段的ISQ值均无显著差异（P〉0．05）,整体变化趋势相同：表现为初期稳定性均较高,于第1周至第4周下降,第6周逐步上升,其后稳定性基本保持不变或略有上升。随访期（修复后6个月）间,2组种植体的留存率均为100％。结论：ITISLA表面种植体早期负载是可行的。     

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.     

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.