Prospective 10‐Year Cohort Study Based on a Randomized Controlled Trial (RCT) on Implant‐Supported Full‐Arch Maxillary Prostheses. Part 1: Sandblasted and Acid‐Etched Implants and Mucosal Tissue

Background: There have been very few long‐term controlled studies (i.e., over 5 years duration) focusing on marginal conditions for implants with a sandblasted, large grit, and acid‐etched (SLA) surface. Purpose: To evaluate and report 10‐year data on outcomes of implants with an SLA surface placed in the edentulous maxilla. Materials and Methods: In a randomized controlled trial (RCT) cohort of 24 patients, the outcomes of implants with an SLA surface were registered. The RCT cohort has previously been reported after 1 year, 3 years, and 5 years of loading. Results: One patient dropped out of the study prior to the 10‐year control. Of the 23 remaining patients, the implant survival rate was 95.1%. If implants of unknown status were also considered lost, that is, one drop‐out patient with three implants for whom no information could be obtained, the implant survival rate was 93%. The mean marginal bone loss from baseline (139 implants) to 10 years (102 implants) was 1.07 mm (standard deviation 0.98). One implant out of 102 available for radiographic examination according to the original protocol showed a bone loss exceeding 4 mm. Of the 84 implants available for clinical examination, none showed a Plaque Index or sulcus bleeding index of 3. The mean implant stability quotient was significantly higher for mesial–distal versus buccal–palatal measurements. Conclusion: The implant survival was 95.1%. The mean value of bone loss after 10 years was 1.07 mm. Peri‐implantitis were noted at the 5‐year follow‐up for one patient with a previous history of periodontitis; this patient did not attend the 10‐year follow‐up. This study shows that sandblasted and acid‐etched implants offers predictable long‐term results as support for full‐arch maxillary prostheses.     

Immediate occlusal loading of Brånemark implants applied in various jawbone regions: a prospective, 1-year clinical study

Background: The original protocol for dental implant treatment ad modum Brånemark was based on submerged healing prior to loading. For patients, immediate implant function could reduce cost and increase attractiveness of implant treatment. Purpose: The goal of this study was to evaluate the short‐term success rate of immediately loaded implants placed in various regions of the jaws. Materials and Methods: Forty‐one patients received a total of 127 immediately loaded implants (76 maxillary and 51 mandibular). Seventy‐one percent of the patients received their prosthetic restoration the same day and the others within 11 days. All prosthetic constructions were in full contact in centric occlusion. Clinical follow‐up examinations were performed at 1 week, 2 weeks, and at 1, 2, 3, 6, and 12 months after implant loading. The study was completed 1 year after loading. Results: Twenty‐two implants were lost in 13 patients (including 7 maxillary implants lost in 1 patient). The cumulative success rate of the implants was 82.7% after 1 year of prosthetic loading. All sites with implant losses were re‐implanted, using a two‐stage technique, with no further complications reported. Ninety‐one percent of implants placed in regions other than the posterior maxilla were successful compared with 66% of implants placed in the posterior maxilla. Implants in patients with a parafunctional habit (bruxers) were lost more frequently than those placed in patients with no para‐function (41% vs. 12%). Implants subjected to guided bone regeneration were more successful compared with those not subjected to regeneration procedures (90% vs. 67%). Conclusions: The immediate loading concept is a realistic treatment alternative in various jawbone regions except for the posterior part of the maxilla. High occlusal loads should be considered a risk factor. On the other hand, implants in combination with bone defects frequently are penetrating cortical layers to a higher extent, thereby contributing to implant stability during the healing phase and consequently do not inevitably jeopardize the treatment result. However, further controlled clinical studies with larger sample sizes need to be performed to evaluate the influence of different parameters on treatment outcome.     

Stability, marginal bone loss and survival of standard and modified sand-blasted, acid-etched implants in bilateral edentulous spaces: a prospective 15-month evaluation

Objectives: Chemical modification of the already proven sand‐blasted and acid‐etched (SLA) implant had increased its surface wettability and consequent early‐term osseointegration characteristics. The aim of this clinical trial was to compare the stability changes, success, survival, peri‐implant parameters and marginal bone loss (MBL) of the early‐loaded standard (SLA) and modified sand‐blasted, acid‐etched (modSLA) implants. Material and methods: A total of 96 SLA and modSLA implants were placed in a bi‐lateral, cross‐arch position to the jaws of 22 patients. Resonance frequency analysis (RFA) was used to measure the implant stability in the surgery and following healing after 1, 3 and 6 weeks. At the stage of loading, a panoramic X‐ray was obtained and RFA measurement was repeated for all implants. Implants were restored by metal–ceramic crowns and followed for 1 year to determine the success, survival rate, peri‐implant parameters and MBL. Results were compared by one‐ and two‐way ANOVA, log‐rank test and generalized linear mixed models (P<0.05). Results: One modSLA implant was lost after 3 weeks following the surgery yielding to a 100 and 97.91% success rate for SLA and modSLA implants, respectively (P=0.323). At the loading stage, modSLA implants showed significantly lower MBL (0.18 ± 0.05 mm) than SLA implants (0.22 ± 0.06 mm; P=0.002). In the loading stage, RFA value of the modSLA implants (60.42 ± 6.82) was significantly higher than the both implant types in the surgical stage (55.46 ± 8.29 and 56.68 ± 8.19), and following 1 (56.08 ± 7.01 and 55.60 ± 9.07) and 3 weeks of healing (55.94 ± 5.95 and 55.40 ± 6.50 for SLA and modSLA implants, respectively). Conclusions: modSLA implants demonstrated a better stability and a reduced MBL at the loading stage. Both SLA and modSLA implants demonstrated a favorable success and survival at the end of 15‐month follow‐up. To cite this article :
Karabuda ZC, Abdel‐Haq J. Arιsan V. Stability, marginal bone loss and survival of standard and modified sand‐blasted, acid‐etched implants in bilateral edentulous spaces: a prospective 15‐month evaluation.
Clin. Oral Impl. Res. 22 , 2011; 840–849
doi: 10.1111/j.1600‐0501.2010.02065.x     

The clinical and radiographic outcome of implants placed in the posterior maxilla with a guided flapless approach and immediately restored with a provisional rehabilitation: a randomized clinical trial

Objectives: To evaluate and compare the outcome of dental implants placed using a flapless protocol and immediate loading with a conventional protocol and loading after 6 weeks. Materials and methods: Fourteen patients with bilateral maxillary edentulous areas were treated using Straumann SLA‐implants. Using a randomized split‐mouth design, implants were placed in one side of the maxilla using a stereolithographic surgical guide for flapless surgery and immediately loaded on temporary abutments with a bridge (test). Implants in the other side were placed using the conventional protocol and loaded after 6 weeks of healing (control). Clinical and radiographic evaluation of peri‐implant tissues was performed at time of implant surgery, and after 1 week, 6 weeks, 3, 6, 12 and 18 months. Results: A total of 70 implants were placed (36 test and 34 control). One implant (test) was lost after 3 months, resulting in a survival rate of 97.3% for the test implants and 100% for the control implants. Marginal bone levels were not statistically significantly different between the test and control implants but at baseline the marginal bone level was significantly lower compared to the other evaluation periods (P < 0.05). The mean bone level for test and control implants was 1.95 mm ± 0.70 and 1.93 mm ±0.42 after 18 months, respectively. There was a significant change in height of the attached mucosa at implants placed with a conventional flap between post‐operative and 1 week and between 1 week and 6 weeks. Statistically significant differences were found between the test side and the control side for opinion about speech, function, aesthetics, self‐confidence and overall appreciation the first 6 weeks. Conclusion: Implants can successfully integrate in the posterior maxilla using a flapless approach with immediate loading similar to a conventional protocol. The mucosal tissues around implants placed with a conventional flap changed significantly compared with flapless placed implants. To cite this article:
Van de Velde T, Sennerby L, De Bruyn H. The clinical and radiographic outcome of implants placed in the posterior maxilla with a guided flapless approach and immediately restored with a provisional rehabilitation: a randomized clinical trial.
Clin. Oral Impl. Res. 21 , 2010; 1223–1233.
doi: 10.1111/j.1600‐0501.2009.01924.x     

In vivo performance of zirconia and titanium implants: a histomorphometric study in mini pig maxillae

Objectives: To compare the bone tissue response to surface‐modified zirconia (ZrO₂) and titanium implants. Methods: Cylindrical low‐pressure injection moulded zirconia (ZrO₂) implants were produced with an acid‐etched surface. Titanium implants with identical shape, sandblasted and acid‐etched surface (SLA) served as controls. Eighteen adult miniature pigs received both implant types in the maxilla 6 months after extraction of the canines and incisors. The animals were euthanized after 4, 8 and 12 weeks and 16 zirconia and 18 titanium implants with the surrounding tissue were retrieved, embedded in methylmethacrylate and stained with Giemsa–Eosin. The stained sections were digitized and histomorphometrically analysed with regard to peri‐implant bone density (bone volume/total volume) and bone–implant contact (BIC) ratio. Statistical analysis was performed using Mann–Whitney' U‐test. Results: Histomorphometrical analysis showed direct osseous integration for both materials. ZrO₂ implants revealed mean peri‐implant bone density values of 60.4% (SD ± 9.9) at 4 weeks, 65.4% (SD ± 13.8) at 8 weeks, and 63.3% (SD ± 21.5) at 12 weeks after implantation, whereas Ti‐SLA implants demonstrated mean values of 61.1% (SD ± 6.2), 63.6% (SD ± 6.8) and 68.2% (SD ± 5.8) at corresponding time intervals. Concerning the BIC ratio, the mean values for ZrO₂ ranged between 67.1% (SD ± 21.1) and 70% (SD ± 14.5) and for Ti‐SLA between 64.7% (SD ± 9.4) and 83.7% (SD ± 10.3). For the two parameters investigated, no significant differences between both types of implants could be detected at any time point. Conclusion: The results indicate that there was no difference in osseointegration between ZrO₂ implants and Ti‐SLA controls regarding peri‐implant bone density and BIC ratio. To cite this article :
Gahlert M, Roehling S, Sprecher CM, Kniha H, Milz S, Bormann K. In vivo performance of zirconia and titanium implants: a histomorphometric study in mini pig maxillae.
Clin. Oral Impl. Res. 23 , 2012; 281–286.
doi: 10.1111/j.1600‐0501.2011.02157.x     

Immediate and delayed implant placement into extraction sockets: a 5-year report

Background: As a complement to the earlier reported 3‐year results from a prospective multicenter study of immediate and delayed placement of implants into fresh extraction sockets, the 5‐year results are reported. Purpose: The purpose of this 5‐year report was to evaluate the immediate and long‐term success of implants placed into fresh extraction sockets, with respect to implant size and type, bone quality and quantity, implant position, initial socket depth, and reason for tooth extraction. Materials and Methods: This paper presents the 5‐year results of the original 12 centers that participated with 143 consecutively included patients. A total of 264 implants were placed either immediately after tooth extraction or after a short soft‐tissue healing time (3–5 weeks). The patients were divided into five subgroups, depending on the type of insertion method used. Results: The outcome demonstrated that the cumulative implant survival rate after 5 years of loading has not changed and remains 92.4% in the maxilla and 94.7% in the mandible. No difference in failure rates can be seen between the groups when relating the failures to insertion method. Conclusion: This prospective study demonstrated that placing Brånemark implants into fresh extraction sites can be successful over a period of 5 years of loading. One of the outcomes of the study shows that there is a clinical correlation between implant failure and periodontitis as a reason for tooth extraction, even if it is difficult to give it a casual association. It can be hypothesized that periodontitis affected tissues might have a negative local influence because of the presence of infrabony defects that could possibly increase the gap between bone and implant or jeopardize achievement of primary stability.     

Five-year results from a randomized, controlled trial on early and delayed loading of implants supporting full-arch prosthesis in the edentulous maxilla

Objectives: The overall aim was to compare the clinical outcomes of early and delayed implant loading in the totally edentulous maxilla during 5 years of function. Materials and methods: Twenty‐four patients with edentulous maxillae were randomized in two groups and subjected to early (test, n=16) or delayed (control, n=8) loading. A total of 142 implants were placed and 139 implants (Straumann AG) were loaded with full‐arch bridges and followed for 5 years. Results: All patients received and maintained a fixed bridge throughout the study period. Five (5.3%) test implants in three patients and two (4.3%) control implants in two patients were lost during the 5 years (NS). There were no differences in implant stability as measured with resonance frequency analysis at 5 years. More bone loss occurred at test than at control implants, ?0.8 mm (SD 1.2) vs. ?0.3 mm (SD 1.1), respectively. However, test implants showed a more coronal marginal bone level than control implants after 5 years, 2.9 mm (SD 1.1) vs. 3.7 mm (SD 1.2) from the implant shoulder, respectively. No control implants and four (4.4%) test implants in three (18.8%) patients showed >3 mm bone loss after 5 years. Two of the latter implants in one patient also showed increased probing depths, bleeding at probing and plaque accumulation. Tooth fracture was the most common prosthetic complication. The use of lingual gold onlay effectively reduced the number of resin‐related complications as opposed to a resilient mouth guard. Conclusions: The present randomized controlled trial showed no important differences between early and delayed loading of implants in the edentulous maxilla after 5 years of function. A favourable long‐term marginal bone response to the sandblasted large‐grit acid‐etched (SLA) surface was observed. Technical complications were mainly resin‐related which could be avoided by the use of a lingual gold onlay. It is concluded that early loading of SLA‐surface implants for support of full‐arch bridges represents a viable therapy for the totally edentulous maxilla.     

Comparison of two early loading protocols in full arch reconstructions in the edentulous maxilla using the Cresco prosthetic system: a three-arm parallel group randomized-controlled trial

Objectives: Appraise the feasibility of interchanging conventional components of a fixed dental prosthesis (FDP) with those of Cresco in two different early loading protocols. Material and methods: In five centers patients with an edentulous, fully healed maxilla were recruited to partake in a three‐arm blinded randomized‐controlled trial (RCT). Each patient received 5/6 implants using a single‐stage surgery approach to support a 10/12‐unit FDP. The implants used were SLA solid screw two‐part implants. In test groups 1 and 2 components from Cresco were used and the implants loaded 10 days or 6–8 weeks post‐implant placement. Group 3 received their FDP fabricated with conventional components 6–8 weeks post‐implant placement. Patients were followed up 3 years. Results: Of 36 patients, 30 remained after 3 years. The adjusted means and ranges of changes in crestal bone levels were ?0.65, ?0.5 and ?0.4 mm in groups 1, 2 and 3, respectively. The change from baseline was statistically significant in all treatment groups. Adjusting for the difference in implant depth, there was an expected additional change in bone level of ?0.29 mm by each 1 mm the implant was placed deeper. There was no significant difference between the 6‐8 weeks post‐implant placement loading Cresco group vs. the control group or between the two Cresco groups. Conclusions: The vertical placement has more effect on bone loss than the fabrication technique used for the suprastructure and whether the implants were loaded after 10 days vs. 6–8 weeks. To cite this article :
Jokstad A, Ellner S, Gussgard A. Comparison of two early loading protocols in full arch reconstructions in the edentulous maxilla using the Cresco prosthetic system: a three‐arm parallel group randomized‐controlled trial.
Clin. Oral Impl. Res. 22 , 2011; 455–463.
doi: 10.1111/j.1600‐0501.2010.02156.x     

Rehabilitation of irradiated patients with chemically modified and conventional SLA implants: five‐year follow‐up

The aim of this study is to evaluate the clinical and radiological parameters of standard SLA surface implants compared to chemically modified hydrophilic SLActive implants in irradiated patients after the initial 12‐month loading period up to 5 years. Twenty patients with a mean age of 61·1 years were treated with dental implants after ablative surgery and radio‐chemotherapy of oral cancer. All patients were non‐smokers. The placement of 102 implants (50 SLA, 52 SLActive) was performed bilaterally according to a split‐mouth design. Mean crestal bone changes were evaluated using standardised orthopantomographies and clinical parameters. Data were analysed using a Kaplan–Meier curve, Mann–Whitney U‐test and two‐factorial non‐parametric analysis. The average observation period was 60 months. The amount of bone loss at the implant shoulder of SLA implants was mesial and distal 0·7 mm. The SLActive implants displayed a bone loss of mesial 0·6 mm as well as distal 0·7 mm after 5 years. Two SLA implants were lost before loading. One patient lost five implants due to recurrence of a tumour. The overall cumulative 12‐month, 3‐year and 5‐year survival rate of SLA implants was 92%, 80% and 75·8% and of SLActive implants 94·2%, 78·8% and 74·4%, respectively. Eighteen implants were considered lost because the patients had died. Sandblasted acid‐etched implants with or without a chemically modified surface can be used in irradiated patients with a high predictability of success. Lower implant survival rates in patients with irradiated oral cancer may be associated with systemic effects rather than peri‐implantitis.     

A prospective study evaluating a protocol for 6 weeks' loading of SLA implants in the posterior maxilla: one year results

Experimental and clinical studies have shown that modification of implant surfaces can result in increased bone-to-implant contact at earlier times thus reducing the healing period between surgery and prosthesis. Sandblasted and acid-etched (SLA) implants are in this category and have successfully undergone early loading in patients with good bone quality and quantity. Nevertheless, premature loading of SLA implants was not routinely possible in predominantly trabecular bone, such as the posterior maxilla, as it is often characterized by a deficiency in initial bone to implant contact. The purpose of this prospective clinical investigation is to evaluate the efficacy of a modified surgical protocol followed by loading SLA implants at 6 weeks in the posterior maxilla. Drilling was limited to the minimum, and most of the site preparation was produced with osteotomes. Screw tapping was never performed and primary stability was always achieved. Abutment connection was carried out at 15 Ncm 43 (+/- 1) days after surgery and provisional restoration was fabricated. Further abutment tightening at 35 Ncm was performed after an additional 6 weeks. Of the 36 SLA implants placed in 19 patients, one was lost before final restoration. Clinical and radiographic measures were taken at baseline and 1 year postoperatively. The preliminary results suggest that, by means of the surgical and restorative technique presented, SLA implants are suitable for loading at 6 weeks in the posterior maxilla. More years of observation will verify whether osseointegration can be equally maintained over a long period.     

Rehabilitation of irradiated patients with modified and conventional sandblasted acid-etched implants: preliminary results of a split-mouth study

Purpose: The aim of this study was to evaluate the success rate of chemically modified and conventional sandblasted acid‐etched surface (SLA) titanium implants in irradiated oral squamous cell carcinoma patients. Material and methods: Twenty patients with a mean age of 61.1 years were treated with dental implants after ablative surgery and radio‐chemotherapy of oral cancer. All patients were non‐smokers. The placement of SLA and modSLA implants was performed bilaterally according to a split‐mouth design. All 102 implants (50 SLA, 52 modSLA) placed showed an unloaded healing time of 6 weeks in the mandible and 10 weeks in the maxilla. Mean crestal bone changes using standardized orthopantomographies and clinical parameters like pocket depths, mPII and mBI were evaluated. Results: Of 102 implants, 55 implants (27 SLA implants, 28 modSLA) were located in the maxilla and 47 implants (23 SLA, 24 modSLA) in the mandible. The average observation period was 14.4 months. The amount of bone loss at the implant shoulder of SLA implants was 0.4 mm mesial and 0.4 mm distal. The modSLA implants displayed a bone loss of mesial 0.3 mm and distal 0.3 mm. Two SLA implants were lost resulting in a success rate of 96%. The success rate of modSLA implants was 100%. Conclusion: Regarding the data found in this investigation, we can conclude that implants with chemically modified and conventional SLA titanium surface show high success rates in irradiated patients. SLA implants with or without a chemically modified surface regardless of the location can be restored with a high predictability of success at least in the short time range observed. To cite this article:
Heberer S, Kilic S, Hossamo J, Raguse J‐D, Nelson K. Rehabilitation of irradiated patients with modified and conventional sandblasted, acid‐etched implants: preliminary results of a split‐mouth study.
Clin. Oral Impl. Res. 22 , 2011; 546–551
doi: 10.1111/j.1600‐0501.2010.02050.x     

Vertical Osteoconductive Characteristics of Titanium Implants with Calcium‐Phosphate‐Coated Surfaces – A Pilot Study in Rabbits

Introduction: Osteoconductive characteristics of different implant surface coatings are in the focus of current interest. The aim of the present study was to compare the vertical osteoconductivity at the implant shoulder of supracrestal inserted calcium‐phosphate coated implants (SLA‐CaP) with conventional sand‐blasted/acid‐etched (SLA) implants in a rabbit model. Materials and Methods: SLA‐CaP and SLA implants were inserted bilaterally in the mandible of four rabbits in a split‐mouth design. The implants were placed 2 mm supracrestal. After 3 weeks, at the left and right implant shoulder, the percentage of linear bone fill (PLF) as well as bone‐implant contact (BIC‐D) were determined. Results: After 3 weeks, newly formed woven bone could be found at the shoulder of the most of both surface‐treated implants (75%). PLF was significantly higher in SLA‐CaP implants (11.2% vs. 46.5%; n = 8, p = .008). BIC‐D was significantly increased in the SLA‐CaP implants (13.0% vs. 71.4%; n = 8, p < .001) as well. Conclusion: The results of this study show for the first time that calcium‐phosphate coated surfaces on supracrestal inserted implants have vertical osteoconductive characteristics and increase the bone‐implant contact at the implant shoulder significantly in a rabbit model. In clinical long‐term settings, these implants may contribute to a better vertical bone height.     

Immediately restored single implants in the aesthetic zone of the maxilla using a novel design: 1-year report

Objectives: To evaluate immediate placement and immediate restoration of a novel implant with a 12°‐angled prosthodontic platform, in fresh extraction sockets of the aesthetic zone of the maxilla. Materials and methods: Tapered, roughened surface implants of 4 mm (n=15) or 5 mm (n=13) diameter were placed in 27 participants (mean age: 47.1 years; range: 21–71 years) requiring an immediate replacement of single anterior maxillary teeth. Provisional screw‐retained all‐ceramic crowns were placed within 4 h following optical impressions. At 8 weeks (baseline), definitive screw‐retained all‐ceramic crowns were placed in occlusion. Results: Twenty‐six of the 28 implants met the inclusion criteria at surgery. Marginal bone levels revealed bone gain between surgery and baseline, and between baseline and 1 year of 0.2 mm (SD 0.75) and 0.78 mm (SD 2.45). Mean mid‐buccal mucosal margins showed gains of 0.2 mm (SD 0.44). Prosthodontic maintenance and the aesthetics of the screw‐retained implant crowns were facilitated by the external hex 12°‐angled prosthodontic platform on the novel implant design, re‐orientating the access cavity to the palatal or occlusal surfaces. All‐ceramic implant crowns showed a high success rate with low maintenance issues over 1 year. Conclusion: Tapered, roughened‐surfaced implants with a novel 12°‐angled prosthodontic platform immediately placed in fresh extraction sockets, immediately restored with provisional crowns and subsequent definitive crowns at 8 weeks were successful for 1 year. To cite this article:
Brown SDK, Payne AGT. Immediately restored single implants in the aesthetic zone of the maxilla using a novel design: 1‐year report.
Clin. Oral Impl. Res. 22 , 2011; 445–454.     

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.     

Early loading of unsplinted implants supporting mandibular overdentures using a one-stage operative procedure with two different implant systems: a 2-year report

Background: Step‐wise reduction in loading protocols is necessary to evaluate early loading of implants with mandibular overdentures. Purpose: To compare the success rates of two different dental implant systems following conventional or early loading protocols in patients being rehabilitated with mandibular overdentures. Materials and Methods: Forty‐eight edentulous participants were randomly allocated to two different implant systems: one with a machined titanium implant surface (Sterioss, Nobel Biocare, Yorba Linda, California, USA) and the other with a roughened titanium surface (Southern Implants, Irene, South Africa). For each system, the participants were further divided into control groups, in whom mandibular implant overdentures and their respective matrices were inserted following a standard 12‐week healing period, and test groups, in whom a 6‐week healing period was followed prior to identical loading. Two unsplinted implants to support implant overdentures were placed in the anterior mandible of all participants, using a standardized one‐stage surgical procedure. Mobility tests and marginal bone levels, as well as periimplant parameters, were evaluated at each baseline and 52 and 104 weeks after surgery. Results: There was no statistically significant difference in the success rates of the two systems in either control or test groups. At the 2‐year evaluation, a success rate was found of 87.5% and 70.8.% for the control and test Sterioss groups, respectively, and 83.3% and 100% for the control and test Southern Implants groups were observed. For the Sterioss groups, eight implants were lost at an early stage: seven in the test group and one in the control group. For the Southern Implants control and test groups, no failures were seen at any time interval. There were no significant differences in marginal bone loss, Periotest values, and peri‐implant parameters between implant systems or between any of the control or test groups. Conclusions: Early loading, with step‐wise reductions in loading protocols, of unsplinted machined Sterioss and roughened Southern Implants fixtures with mandibular overdentures is possible for up to 2 years.     

Extra short dental implants supporting an overdenture in the edentulous maxilla: a proof of concept

Objectives: This study investigates the outcome of short implants additionally placed with longer implants to support a maxillary overdenture. Materials and methods: Twelve patients received six implants to support a maxillary overdenture. Only one patient still had two molars in the maxilla, while the others had no remaining teeth. The status of the opposing arch was diverse. The distal implant in each quadrant was 6 mm in height (S) and the middle implants ranged between 10 and 14 mm (L). All implants were placed following a one‐stage procedure and early loaded (6 weeks). Clinical and radiological parameters were assessed 6, 12 and 24 months after loading. Results: One short implant failed 2 weeks after surgery, probably due to early mobilization by the provisional prosthesis. The mean bone loss on the rough part of the implant was 0.7 mm (S) vs. 1.3 mm (L) during the first year and 0.3 mm (S) vs. 0.2 mm (L) during the second year after loading. The mean implant stability quotient values were 67 (S) vs. 70 (L) at placement and 75 (S) vs. 78 (L) after 1 year. At the 2‐year follow‐ up, all prostheses were still stable and comfortable. Conclusion: An overdenture on six implants, of which two have a reduced length, might represent a successful treatment option. No significant difference could be found between both implant lengths at 2 years' follow‐up. However, bone loss with short implants may increase the likelihood of failure.     

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。     

Factors influencing resonance frequency analysis assessed by Osstell™mentor during implant tissue integration: II. Implant surface modifications and implant diameter

Objectives: To monitor the development of the stability of Straumann^® tissue‐level implants during the early phases of healing by resonance frequency analysis (RFA) and to determine the influence of implant surface modification and diameter. Material and methods: A total of twenty‐five 10 mm length implants including 12 SLA RN ?4.1 mm implants, eight SLActive RN ?4.1 mm implants and five SLA WN ?4.8 mm implants were placed. Implant stability quotient (ISQ) values were determined with Osstell^?mentor at baseline, 4 days, 1, 2, 3, 4, 6, 8 and 12 weeks post‐surgery. ISQ values were compared between implant types using unpaired t‐tests and longitudinally within implant types using paired t‐tests. Results: During healing, ISQ decreased by 3–4 values after installation and reached the lowest values at 3 weeks. Following this, the ISQ values increased steadily for all implants and up to 12 weeks. No significant differences were noted over time. The longitudinal changes in the ISQ values showed the same patterns for SLA implants, SLActive implants and WB implants. At placement, the mean ISQ values were 72.6, 75.7 and 74.4, respectively. The mean lowest ISQ values, recorded at 3 weeks, were 69.9, 71.4 and 69.8, respectively. At 12 weeks, the mean ISQ values were 76.5, 78.8 and 77.8, respectively. The mean ISQ values at all observation periods did not differ significantly among the various types. Single ISQ values ranged from 55 to 84 during the entire healing period. Pocket probing depths of the implants ranged from 1 to 3 mm and bleeding on probing from 0 to 2 sites/implant post‐surgically. Conclusions: All ISQ values indicated the stability of Straumann^® implants over a 12‐week healing period. All implants showed a slight decrease after installation, with the lowest ISQ values being reached at 3 weeks. ISQ values were restored 8 weeks post‐surgically. It is recommended to monitor implant stability by RFA at 3 and 8 weeks post‐surgically. However, neither implant surface modifications (SLActive) nor implant diameter were revealed by RFA. To cite this article:
Han J, Lulic M, Lang NP. Factors influencing resonance frequency analysis assessed by Osstell^?mentor during implant tissue integration: II. Implant surface modifications and implant diameter.
Clin. Oral Impl. Res. 21 , 2010; 605–611.
doi: 10.1111/j.1600‐0501.2009.01909.x     

下颌无牙颌种植固定修复早期负载的临床观察

目的:评价下颌无牙颌种植固定修复早期负载的可行性和临床疗效。方法:14例下颌无牙颌病例共植入94颗ITISLA种植体,种植体植入后第6周完成固定修复。于植入当天、第4周、修复后1年行影像学检查,观察种植部位牙槽骨吸收情况。在植入即刻及第4周行共振频率分析。结果:种植体1年成功率为100%,修复体的1年成功率为100%。影像学检查示种植体周无低密度影;种植部位牙槽骨水平未见明显吸收,均位于种植体第一螺纹的冠方,从全景片测量得1年牙槽骨水平吸收为(0.3±0.94)mm。共振频率分析显示,植入即刻与第4周分别为69.54±4.29和63.14±5.57。结论:ITI SLA种植体固定修复下颌无牙颌早期负载是可行的。     

Immediate rehabilitation of the edentulous jaws with full fixed prostheses supported by four implants: interim results of a single cohort prospective study

Objectives: The purpose of this study was to prospectively evaluate the clinical and radiographic outcomes of immediately loaded full‐arch fixed prostheses supported by a combination of axially and non‐axially positioned implants in a large cohort of patients with completely edentulous jaws, up to 5 years of function. Materials and methods: One hundred and seventy‐three edentulous patients (80 males and 93 females) were enrolled according to specific selection criteria. Each patient received a full‐arch fixed prosthesis supported by two distal tilted implants and two anterior axially placed implants. The provisional functional acrylic prosthesis was delivered the same day as surgery in all cases. All cases were finalized 4–6 months later. The patients were scheduled for follow‐up at 6 and 12 months of function, and annually up to 5 years. At each follow‐up plaque and bleeding score was assessed and radiographic evaluation of marginal bone level was performed. Results: The overall follow‐up range was 4–59 months. A total of 154 immediately loaded prostheses (61 in the maxilla and 93 in the mandible) were in function for at least 1 year and were considered for the analysis. Four axially placed implants failed in the maxilla and one tilted implant in the mandible, all within 6 months of loading. No further implant failure occurred to date. Implant survival at 1 year was 98.36% and 99.73% for the maxilla and the mandible, respectively. Marginal bone loss at 1 year averaged 0.9±0.7 mm in the maxilla (204 implants) and 1.2±0.9 mm in the mandible (292 implants). No difference was found in marginal bone loss between axial and tilted implants. Plaque and bleeding scores progressively improved from 6 to 12 months. Fracture of the acrylic prosthesis occurred in 14% of total cases. Conclusions: The present preliminary results from a relatively large sample size suggest that the present technique can be considered a viable treatment option for the immediate rehabilitation of both mandible and maxilla. To cite this article:
Agliardi E, Panigatti S, Clericò M, Villa C, Malò P. Immediate rehabilitation of the edentulous jaws with full fixed prostheses supported by four implants: interim results of a single cohort prospective study.
Clin. Oral Impl. Res. 21 , 2010; 459–465.
doi: 10.1111/j.1600‐0501.2009.01852.x