Immediate non-occlusal vs. early loading of dental implants in partially edentulous patients: a multicentre randomized clinical trial. Peri-implant bone and soft-tissue levels

Objectives: To compare peri‐implant bone and soft‐tissue levels of immediately non‐occlusally loaded vs. non‐submerged early loaded implants in partially edentulous patients up to 14 months after placement. Material and methods: Fifty‐two patients were randomized in five Italian private practices: 25 in the immediately loaded group and 27 in the early loaded group. To be immediately loaded, single implants had to be inserted with a torque of ≥30 N cm, and splinted implants with a torque of ≥20 N cm. Immediately loaded implants were provided with non‐occluding temporary restorations within 48 h. After 2 months, the provisional restorations were placed in full occlusion. Implants were early loaded after 2 months. Final restorations were provided 8 months after placement. Blinded assessors evaluated peri‐implant bone and soft‐tissue levels. Results: Fifty‐two implants were immediately loaded and 52 were early loaded. No drop‐out occurred. One single immediately loaded implant failed 2 months after placement. Both groups gradually lost peri‐implant bone in a highly statistically significant manner at 2, 8, and 14 months. After 14 months, patients of both groups lost an average of 1.1 mm of peri‐implant bone. There were no statistically significant differences between the two loading strategies for peri‐implant bone and soft‐tissue level changes (P>0.05). After 14 months, the position of the soft tissues did not change significantly from baseline (delivery of the final restorations 8 months after placement). Conclusions: There were no statistically or clinically significant differences between immediate and early loading of dental implants with regard to peri‐implant bone and soft‐tissue levels as evaluated in the present study.     

Immediate loading with complete implant-supported restorations in an edentulous heavy smoker: histologic and histomorphometric analyses

The clinical case presented is that of an edentulous female patient, a heavy smoker, who received implant-supported complete restorations in the maxilla and mandible using the immediate loading concept according to the Ankylos implant system. The patient received 12 commercially pure titanium (grade 2) Ankylos implants, 6 in the maxilla and 6 in the mandible. The implants were loaded immediately after surgery with temporary acrylic resin prostheses fabricated chairside using a prefabricated customized splint. The definitive ceramometal restorations were seated 4 months after surgery. Clinical and radiologic evaluation at 7 months after implant placement indicated functional bone anchorage of all implants, despite the patient being a smoker and having poor bone quality. The patient died 7 months after implant placement because of lung cancer; however, there was no known disease at the time of implant placement. After her death, the implants with the surrounding tissues were removed en bloc and examined histologically and histomorphometrically using undecalcified cut and ground sections. All implants were osseointegrated to some extent and surrounded by lamellar bone. However, around the upper, nonthreaded parts of the implants, much of the bone had been resorbed. In this region, fibrous connective tissue was in close contact with the titanium surface. Epithelial proliferation with pocket formation could not be observed in any of the implants. The histomorphometric evaluation of bone-implant contact in threads demonstrated a mean of approximately 51% of the available surface and a mean bone volume of approximately 52%, with a tendency toward greater contact and volume around the implants in the maxilla. If the nonthreaded cylindric portions of the implants were included, mean bone-implant contact was 46% and mean bone volume was 47%.     

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.     

Early loading of sandblasted, acid-etched implants in the posterior maxilla and mandible: a 1-year follow-up report from a multicenter 3-year prospective study

PURPOSE: The aim of the present study was to evaluate the concept of an immediate loading protocol in the posterior maxilla and mandible through analysis of implant survival at 1 year. MATERIALS AND METHODS: One year follow-up data of a multicenter study are reported. Eighty-two ITI sandblasted, acid-etched (SLA) implants in 40 patients were loaded between 0 and 11 days after implant placement (mean 4.3 +/- 2.8 days). The restorations consisted of either 2 splinted crowns or a 3-unit fixed prosthesis. All restorations were put into full functional occlusion. Periapical radiographs were evaluated for changes in crestal bone level from baseline to 1 year postloading. Primary stability of the implants was checked initially and before the fitting of the definitive prosthesis. The restorations were evaluated by the practitioners for retention, stability, and esthetics. RESULTS: Three patients' implants were not loaded because of lack of primary stability, and a fourth patient was excluded from the study because of a protocol violation (more than 4 implants were used). All 4 patients were successfully treated outside the protocol. The overall survival rate of the remaining implants at 1 year was 98.8%. The mean bone loss at 1 year was 0.52 +/- 0.98 mm, which is within the reported limits of less than 1 mm (range 0.4 to 1.4 mm) loss in the first year. DISCUSSION AND CONCLUSION: The early results from this study indicate that early and immediate loading of 2 implants in the posterior maxilla and mandible may be suitable in selected patients. On the basis of 1 year of observation, the results appear similar to those achieved with a delayed procedure.     

Immediate loading of root-form implants: two case reports 3 years after loading

This study examines a protocol for achieving successful osseointegration in immediately loaded implants. With an atraumatic surgical technique and an acceptable biomaterial for implant placement, in certain cases adequate splinting of implants may sufficiently shield the bone-implant interface from functional overload and prevent micromovement from exceeding the allowable limits for successful osseointegration. Two successful cases are presented in which titanium root-form implants were immediately loaded for the support of fixed restorations in the maxilla and the mandible. The authors conclude that for a distinct patient population, immediate loading of multiple, splinted implants may prove to be a valuable adjunct to therapy.     

Immediate functional loading of single-tooth TIO2 grit-blasted implant restorations: a controlled prospective study in a porcine model. Part I: Clinical outcome

Background: Although favorable integration occurs with immediately loaded implants, the relationship between implant outcome, levels of occlusion, and diet requires optimization. Purpose: Pertubating load on single implant restorations immediately after placement by a hard food diet will increase the strains at the bone‐implant interface, increasing the risk for failure. Materials and Methods: Forty‐eight implants replaced the first and third mandibular premolars in 12 pigs, allocated into two groups based on soft‐ and hard‐diet feeding. Cylindrical and tapered implants replaced the first and third premolars, respectively. Each animal received at random four different masticatory loading conditions (group 1 control]: implant with either a cover screw or a healing abutment, and group 2 test]: implant with a crown either with or without occlusal contacts). Results: Thirteen implants out of 44 failed in 11 animals (one with a cover screw, one with a healing abutment, three with nonocclusal, and eight with occlusal restorations). The failure rate of restored implants (either in occlusion or not) was significantly higher in the third premolar sites (p=.007), although diet had no significant effect (p=.421). Conclusions: While diet had no effect on the failure pattern of immediately loaded single implants, the position and type of load under the masticatory mode were significant. Immediately loaded implants both in and out of occlusion were less successful than the controls, and this is probably attributed to detrimental strain induced on the bone‐implant interface.     

Immediate and Early Loading of Chemically Modified Implants in Posterior Jaws: 3‐Year Results from a Prospective Randomized Multicenter Study

Background: There is a lack of well‐designed prospective, randomized clinical trials evaluating the efficacy of immediate and early loading of implants placed in the partially edentulous posterior maxilla or mandible. Purpose: The aim of this study was to evaluate crestal bone level changes over 3 years following immediate or early loading of Straumann implants with a chemically modified surface (SLActive®, Institut Straumann AG, Basel, Switzerland) placed in the posterior maxilla and mandible. Materials and Methods: Subjects received temporary restorations immediately or 28 to 34 days after surgery, with permanent restorations placed at 20 to 23 weeks. Bone level changes were measured by comparison of standardized radiographs taken on the day of implant placement and 5, 12, 24, and 36 months thereafter. Results: Two hundred thirty‐nine of two hundred sixty‐six patients (89.9%) completed the trial. Implant survival rates were 97.4% and 96.7% in the immediate and early loading groups, respectively (p = not significant). Over 36 months, the mean bone level change for immediately loaded implants was 0.88 ± 0.81 mm versus 0.57 ± 0.83 mm for the early‐loaded group (p < .001). After adjusting for a slight difference in initial placement depth, the time of loading had no significant influence on bone level change. Conclusions: Changes in crestal bone level occurred mostly during the first 5 months postloading. After this bone remodeling period, crestal bone level was stable up to 36 months. Implants with a chemically modified surface are safe and predictable for immediate and early loading in the posterior maxilla and mandible.     

A multicenter prospective evaluation of 2-months loaded Osseotite implants placed in the posterior jaws: 3-year follow-up results

Abstract: In this prospective study, the clinical outcome of 2‐months loaded implants placed in the posterior jaws was evaluated after up to 3 years of functional loading. 405 Osseotite^® implants with microtextured acid‐etched surface were consecutively placed in 11 fully and 164 partially edentulous patients (mean age 53.5± 15.3 (S.D.) years) using a one‐stage technique. 282 implants, supporting 154 restorations, were placed in the mandible, while 123 implants, supporting 75 restorations, were placed in the maxilla. A total of 99 single‐tooth restorations, 119 short‐span fixed bridges and 11 full‐arch prostheses were applied. The mean time interval from surgery to connection of provisional restoration was 2.0±0.7 months. 9 failures were reported up to 3 years of follow‐up; of these, 4 mandibular and 2 maxillary implants failed during the initial healing period (before prosthesis connection), while 3 mandibular implants failed after loading. No other complications occurred throughout the study. Life table analysis showed a cumulative survival rate of 97.5% for the mandible and 98.4% for the maxilla. Post‐loading implant survival rate was 98.9% for the mandible and 100% for the maxilla. The excellent outcome of this interim report suggests that microtextured Osseotite^® implants in the posterior jaws may safely bear a functional load applied 2 months after insertion. The results of the present study are particularly encouraging for implants placed in the maxilla, since both a significant reduction of the healing period compared to the 6 months suggested by the classical Brånemark protocol, and an excellent post‐loading function may be achieved also in low quality bone.     

Immediate rehabilitation of the completely edentulous jaw with fixed prostheses supported by either upright or tilted implants: a multicenter clinical study

PURPOSE: The aims of this study were to assess the treatment outcome of immediately loaded full-arch screw-retained prostheses with distal extensions supported by both upright and tilted implants for the rehabilitation of edentulous jaws and to compare the outcomes of upright versus tilted implants. MATERIALS AND METHODS: At 4 study centers, 342 Osseotite NT implants were consecutively placed in 65 patients (96 implants were placed in 24 mandibles and 246 implants in 41 maxillae). The 2 distal implants were tilted by 25 to 35 degrees. Provisional full-arch restorations made of a titanium framework and acrylic resin teeth were delivered within 48 hours of surgery and immediately loaded. The final prosthesis was delivered after 3 months of healing. RESULTS: Three implants failed during the first year and another 2 within 18 months of loading in the maxilla. The cumulative implant survival rate for the maxilla was 97.59% for up to 40 months of follow-up. No implant failure was recorded for the mandible. The prosthetic success rate was 100%. Marginal bone loss around upright and tilted implants was similar. Patients were satisfied of their esthetics, phonetics, and function. CONCLUSION: The preliminary results of this study suggest that immediate rehabilitation of the edentulous maxilla and mandible by a hybrid prosthesis supported by 6 or 4 implants, respectively, may represent a viable treatment alternative with respect to more demanding surgical procedures. The clinical results indicate that immediately loaded tilted implants may achieve the same outcome as upright implants in both jaws.     

Performance of dental implants after staged sinus floor elevation procedures: 5-year results of a prospective study in partially edentulous patients

Objectives: The aim of this prospective study was to evaluate the 5‐year performance and success rate of titanium screw‐type implants with the titanium plasma spray (TPS) or the sand‐blasted, large grit, acid‐etched (SLA) surface inserted in a two‐stage sinus floor elevation (SFE) procedure in the posterior maxilla. Material and methods: A total of 59 delayed SFEs were performed in 56 patients between January 1997 and December 2001, using a composite graft with autogenous bone chips combined with deproteinized bovine bone mineral (DBBM) or synthetic porous β‐tricalcium phosphate (β‐TCP). After a healing period averaging 7.75 months, 111 dental implants were inserted. After an additional 8–14‐week healing period, all implants were functionally loaded with cemented crowns or fixed partial dentures. The patients were recalled at 12 and 60 months for clinical and radiographic examination. Results: One patient developed an acute infection in the right maxillary sinus after SFE and did not undergo implant therapy. Two of the 111 inserted implants had to be removed because of a developing atypical facial pain, and 11 implants were lost to follow‐up and were considered drop‐outs. The remaining 98 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. The measurement of the bone crest levels (DIB values) indicated stability as well. Based on strict success criteria, all 98 implants were considered successfully integrated, resulting in a 5‐year success rate of 98% (for TPS implants 89%, for SLA implants 100%). Conclusion: This prospective study assessing the performance of dental implants inserted after SFE demonstrated that titanium implants can achieve and maintain successful tissue integration with high predictability for at least 5 years of follow‐up in carefully selected patients.     

Immediate loading of 190 endosseous dental implants: a prospective observational study of 40 patient treatments with up to 2-year data

PURPOSE: The present study was undertaken to determine the feasibility of using primary stability as a predictor of implant success in patients whose implants were immediately loaded. MATERIALS AND METHODS: The study included 40 patients, in whom a total of 190 implants were placed, 102 in maxillary sites and 88 in mandibular sites. All were loaded within 72 hours of placement. Sixteen patients were completely edentulous in the mandible and/or the maxilla. The remaining 24, who were partially edentulous, received fixed partial dentures or single-implant restorations. All of the definitive implant restorations were screw retained. The criterion for loading was clinical judgment of primary stability, verified by a "screw test." Impressions were made after implant placement to facilitate the fabrication of a laboratory-made heat-processed provisional restoration from acrylic resin. Following a 4-month period for osseointegration and soft tissue healing, definitive fixed prostheses were fabricated. RESULTS: There were no surgical complications. After 1 to 2 years, all 190 implants had survived and were considered 100% successful, as determined by independent testing of mobility and radiographic evidence of osseointegration. In 4 patients, fracture of the provisional restoration occurred during the healing period. DISCUSSION: Clinical research has shown that immediate loading is a viable treatment modality. The favorable success rate reported in this study for rough-surfaced implants suggests that adherence to a protocol, an important parameter of which is primary stability above 32 Ncm, can lead to osseointegration. CONCLUSION: The results of this limited investigation suggest that patients who are partially or completely edentulous may be immediately restored with implants and fixed provisional restorations, provided that the dental implants are adequately stable immediately after their surgical placement. This alternative therapeutic approach did not appear to affect the up-to-2-year survival of the implants in this patient population.     

Prognosis of immediately loaded implants and their restorations: a systematic literature review

Immediate loading of oral implants has become popular because of the increasing demands of a shortened treatment time. This literature review evaluates the prognosis of immediately loaded implants and their restorations with immediate or delayed implant placement. Special attention was given to the impact of type of jaw, bone quality, implant length, time of implant placement and type of restoration. An electronic (PubMed) and a manual search in relevant journals were conducted until February 2012. Only publications in English, in peer-reviewed journals, were considered. Nine studies met the inclusion criteria: five studies dealt with fixed restorations, two studies with removable rehabilitation of edentulous jaws and two studies dealt with partially edentulous patients. Implant survival rates ranged from 95·8% to 100%, implant success rates in the treatment for the mandible from 79% to 100% and restoration survival rates for both jaws from 96·4% to 100%. Within the limits of this review, appropriate patient selection, primary implant stability, splinting of implants and the expertise of surgeons seem to be important for the prognosis of immediately loaded implants and their restorations. Good bone quality and use of long implants appear to play a role. However, careful interpretation is required because conclusions are based on articles with low level of evidence. While immediate loading of oral implants in the mandible shows encouraging and predictable results, further multicenter randomised controlled clinical trials with sufficient statistical power are needed to examine (i) the outcome of immediately loaded implants in the maxilla and (ii) the outcome of immediate loading of immediately placed implants.     

A 4-year prospective clinical and radiological study of maxillary dental implants supporting single-tooth crowns using early and delayed loading protocols

Background: Recent studies have showed that immediate/early loading of dental implants is a clinically feasible concept with results similar to those for standard two‐stage procedures, especially in the mandible. However, there are only a few studies regarding the immediate/early loading of maxillary implants supporting single‐tooth crowns. Purpose: The aim of this study was to compare the clinical and radiological outcomes of early‐ and delayed‐loaded dental implants supporting single‐tooth crowns in the maxilla. Materials and Methods: Twenty‐nine patients were consecutively treated between 2000 and 2002 with 59 Brånemark System MK III TiUnite implants (Nobel Biocare AB, Göteborg, Sweden) in the maxilla. Two groups were formed according to the loading protocols. In the test group, definitive implant‐supported single crowns were delivered to 19 patients 6 weeks after the implant placement. In the control group, definitive implant‐supported single crowns were delivered to 10 patients 6 months after the implant placement. Clinical and radiographic parameters were recorded at baseline, 1 to 4 years. Implant stability measurements have only been performed at 4‐year follow‐up recall. Results: Overall, three implants were lost during the study period. Two implants were lost in the test group including 36 implants, which indicated a survival rate of 94.4%. One of the lost implants was replaced and then osseointegrated successfully. One implant was lost in the control group during the healing period, which indicated a survival rate of 95.7%. The average marginal bone loss was 1.11 mm for 56 implants after 4 years. There were no significant differences in marginal bone levels, insertion torque, and resonance frequency values between the two groups. Conclusion: The results of this study indicate that 6 weeks of early loading period for TiUnite‐surface titanium implants in the maxilla is reliable and predictable for this patient population and may offer an alternative to the standard loading protocol.     

Immediate loading of modular transitional implants: a histologic and histomorphometric study in dogs

Modular Transitional Implants (MTI) are made from pure titanium and are used to support fixed provisional restorations during the osseointegration of definitive implants. This study histologically examined the jaw response to loaded MTIs in the dog mandible. Three implants were inserted transmucosally into each side of the mandible in 3 dogs. Stability was examined using a Periotest. Anterior and posterior implants were splinted using a cemented acrylic resin fixed partial denture to allow immediate loading. The middle implant remained unloaded and was used as a control. Dogs were sacrificed 11 to 12 weeks after implantation, and tissue blocks containing the implants were removed. Histologic examination showed that 10 of the 18 implants had good bone-to-implant contact, with the percentage of bone contacting the threaded portion of the implant varying from 30% to 65%. There was no statistical difference (p > 0.1) in percentage of bone-to-metal contact between loaded and unloaded implants. Six implants were entirely surrounded by connective tissue with or without inflammation; two implants were lost during the study. The success rate did not differ between loaded and unloaded implants. In the successful implants trabecular bone made good contact with the implant, forming supporting struts. There was bone remodeling in some bone-to-metal contact areas. It is believed that success was mainly influenced by the initial bone density at the implant site and by the uncontrolled load that the animals applied to the implants during the early healing stage.     

Immediately loaded titanium implants with a porous anodized surface with at least 36 months of follow-up

Background: Results from some studies clearly suggest that immediate loading can achieve equal success rates as those found in delayed or unloaded implants. There is still a lack of knowledge about the role of surface oxide properties during the peri‐implant bone healing processes. Purpose: The aim of this study was a clinical follow‐up study of immediately loaded implants with a porous anodized surface. Materials and Methods: A total of 142 TiUnite^TM (Nobel Biocare, Göteborg, Sweden) implants were inserted from January to September 2001. All implants have been used in fixed restorations. Fifty implants were inserted in completely edentulous mandibles, and 69 implants were inserted in completely edentulous maxillae. All 119 implants were subjected to immediate functional loading (IFL) (immediate restoration with full occlusal contact). The other 23 implants, inserted in 12 patients, underwent immediate nonfunctional loading (INFL) (immediate restoration without occlusal contact) in different anatomical configurations (single tooth, small bridges in the anterior mandible, anterior maxilla, and posterior maxilla). All 142 implants have been followed for at least 3 years. Results: All implants appeared to be osseointegrated from a clinical and radiographic point of view. No failures were observed in the IFL and INFL groups. The implant success was 100%. The mean marginal bone loss was 0.8 and 1.0 mm at 12 and 36 months, respectively. Conclusion: Implants with a porous anodized surface appear to work well under an immediate loading state in the long term.     

Treatment of completely edentulous patients with fixed implant-supported restorations: three consecutive cases of simultaneous immediate loading in both maxilla and mandible

This article aims to: (1) describe the treatment of three consecutive completely edentulous patients with fixed implant-supported restorations, including simultaneous same-day immediate loading with fixed provisional restorations in both jaws; and (2) illustrate a step-by-step definitive restoration approach. All patients followed the same diagnostic protocol. One surgical intervention was performed for simultaneous implant placement in both maxilla and mandible. Following implant placement, all patients received a simultaneous, same-day, complete-arch, screw-retained provisional restoration in both jaws according to the "pickup" technique. After healing, final impressions were taken, and occlusion recorder devices were prepared on working casts. For the first occlusal record, the "half-provisionals" method was used. Definitive solid abutments were used for both laboratory and clinical procedures. After casting and finishing, the frameworks were tried in, and a new occlusal record was made. The definitive segmented restorations consisted of four fixed partial dentures in the maxilla and three in the mandible and were cemented with provisional cement. All patients received a nightguard. The pickup technique facilitated simultaneous immediate loading in both maxilla and mandible. A complete, fixed, segmented rehabilitation supported by six to eight anteroposterior implants is a reproducible treatment for completely edentulous patients when optimal anatomic conditions are present.     

Long‐Term Results of Endosteal Implants Following Radical Oral Cancer Surgery with and without Adjuvant Radiation Therapy

Purpose: The aim of this study was to analyze the long‐term survival of implants and implant‐retained prostheses in patients after ablative surgery of oral cancer with or without adjunctive radiation therapy. Materials and Methods: Between 1997 and 2008, 66 patients who had undergone ablative tumor surgery in the oral cavity were treated with dental implants (n = 262). Thirty‐four patients received radiation therapy in daily fractions of 2 Gy administered on 18 to 30 days. Implants were inserted in the maxilla (49; 18.7%) or mandible (213; 81.3%), in non‐irradiated residual (65; 24.8%) or grafted bone (44; 16.8%) and in irradiated residual (15.6%) or grafted bone (39; 14.9%). Seventeen fixed protheses and 53 removable dentures (34 bar attachments, 9 telescopic and 10 ball retained dentures) were inserted. Results: Mean follow‐up after implant insertion was 47.99 (±34.31) months (range 12–140 months). The overall 1‐, 5‐, and 10‐year survival rates of all implants were 96.6%, 96.6%, and 86.9%, respectively. Fourteen implants were lost in nine patients (5.3% of all implants); eight implants were primary losses, and five secondary losses because of an operation of tumor recurrence. There was no significantly lower implant survival for implants inserted into irradiated bone (p = .302), bone and/or soft‐tissue grafts (p = .436), and maxilla or mandible (p = .563). All prosthetic restorations in patients without tumor recurrence could be maintained during the observation period. Conclusions: Implant survival is not significantly influenced by radiation therapy, grafts (bone and/or soft tissue), or location (maxilla or mandible). However, implants placed in irradiated bone exhibit a higher failure rate during the healing period than those placed in non‐irradiated bone. No superstructure was particularly favorable. Osseointegrated implants can be used successfully in patients with prior history of ablative surgery with and without additional radiation therapy.     

Endosseous titanium implants during and after orthodontic load ‐ an experimental study in the dog

An experiment was carried out to determine whether endosseous titanium implants (Brånemarks®) retain their clinical stability throughout a 26‐week period of continuously applied force (2 N) and what kind of marginal peri‐implant bone changes occur in the process. For this purpose 6 premolars (P3: mandible/maxilla and P4: mandible) were extracted from each of 2 foxhounds, and 12 implants (6 per dog) were positioned in the edentulous maxillary and mandibular areas after the alveolar healing period. Following a 25‐week implant healing period, 8 fixtures (P3 areas) were used as anchoring elements for distalization of the 2nd premolars over a period of 26 weeks: 4 implants served as a control group (P4areas of the mandible). There were no clinical or histological signs of implant dislocation after the load application period. In the presence of mild peri‐implant gingivitis, no increase was found in the incidence of marginal bone resorption adjacent to the loaded implants compared with the non‐loaded implants. In the absence of marginal resorption, subperiosteal bone apposition was detected especially around the test implants in the mandible. This suggests that endosseous titanium implants are suitable as anchoring units for longer‐term orthodontic tooth movements. The applied force may moreover induce marginal bone appositions adjacent I to the implants.     

Parameters of resonance frequency measurement values: a retrospective study of 385 ITI dental implants

OBJECTIVES: There is no proven clinical tool to evaluate the amount of osseointegration and stability around dental implants. Therefore, the aim of this retrospective clinical study was to evaluate resonance frequency analysis values of 385 ITI solid screw implants. MATERIAL AND METHODS: Both at implant placement and after healing, implant stability quotients (ISQs) were determined. For statistical analysis, Pearson's correlation coefficients, Welch's two-sample t-tests and paired samples t-tests were computed at a level of significance of alpha=0.05. RESULTS: ISQ values ranged from 39 to 86 at implant placement and from 35 to 89 after healing, showing a significant increase. The highest ISQ values at both stages were obtained in the posterior mandible (P < or = 0.002). After healing, ISQ values in the anterior mandible were significantly higher than in the anterior maxilla (P=0.005). Implant length had a significant influence on ISQ in the anterior mandible (P=0) at insertion and in the anterior (P=0.005) and posterior mandible (P=0.036) after healing. Implant diameter and ISQ at insertion correlated in the anterior mandible (P=0.037). After healing, a significant influence was found for all regions, except the posterior maxilla (P=0.795). With the exception of the anterior maxilla (P=0.542), ISQ at placement had a significant influence on ISQ after healing. In the anterior maxilla (P=0.002) and in the posterior mandible (P=0.007), healing time significantly influenced ISQ after healing. CONCLUSIONS: It appears that only repeated ISQ measurements of a specific implant have some diagnostic benefit, although the parameters influencing the absolute values still remain unclear.     

Single tooth replacement of missing molars: a retrospective study of 78 implants.

As experience with osseointegrated implants has grown, greater use has been made of placement in the posterior jaw. The aim of this study is to present the survival rate of 78 osseointegrated single implants, inserted in the molar area and to evaluate the prosthetic rehabilitation on these teeth. This retrospective study presents findings of 55 consecutive patients with 78 restored single osseointegrated implants in the molar area. The patients went through a clinical and radiological evaluation. The same maxillofacial surgeon inserted all implants. Three of the implants were inserted into the maxilla and 75 into the mandible; 4 of the 78 implants were immediate implants. The cumulative survival rate after one year was 93.6%. Follow-up was up to 80 months, with an average of 27 months. Out of all the implants, 6 failed (7. 7%): 5 failed in the surgical stage, and 1 after prosthetic loading. The main implant failures were among the titanium screw implants. Prosthetic complications occurred in 11 cases (14%), which included loosening of the abutment and/or the crown (9 cases), fracture of the abutment (1 case), and porcelain fracture (1 case). No incident of implant fracture occurred. Within the limits of this study, replacement of a single molar by a single implant is a valid and successful surgical treatment modality, with a high survival rate.