Immediately Loaded Research Articles

Evaluation of peri-implant bone metabolism under immediate loading using high-resolution Na18F-PET.

This study aimed to examine the influence of immediate loading on the dynamic changes of bone metabolism around dental implants using a high-resolution semiconductor sodium 18F-fluoride (Na18F)-PET. Tibiae of 12 adult male rats were divided into 4 groups: immediate loading (IL), no loading (NL), bone defect (BD), and control (CTR). For the IL group, a 4.0-N load was applied continuously by two closed-coil springs attached between two implants in tibia. Each rat received an intravenous injection of Na18F and was scanned by high-resolution Na18F-PET at day 1 and then at weeks 1, 2, 3, 4, 5, 6, and 8 after surgery. Bone metabolism around the implant was evaluated by standardized uptake value (SUV), which indicates the outcome of Na18F accumulation. CT scanning was also performed, and PET and CT images were superposed to determine the anatomical orientation in PET images. Bone metabolism peaked at 7days after surgery and then gradually decreased in all three test groups (IL, NL, and BD). SUVs of all three test groups were significantly higher than the baseline at 1, 2, 3, and 4weeks after surgery, with SUVs in the IL group returning to baseline levels earlier than those in the NL and BD groups. Fluorine integrates preferentially with the initial low-calcified bone; thus, our results suggest that immediate loading promotes the calcification of the bone tissue in the early stage on peri-implant bone formation. Na18F-PET allows for an estimate of bone metabolism change around the implant.

Long-term Outcomes of Immediate Loading of Short Implants: A Controlled Retrospective Cohort Study.

Short implants (≤ 8.5 mm in length) have presented predictable outcomes. However, there is paucity in the long-term evaluation of immediate loading of short implants. The objective of this study was to assess the effect of the immediate loading of short implants on treatment outcomes. Patients having short implants inserted before December 2010 that were immediately loaded were selected. A database was then created to include the patient's data as well as implant- and prostheses-related outcomes. Long implants inserted at the same surgery and immediately loaded by the same prosthesis formed the control group. The proximal bone loss and the survival rates of implants and prostheses were assessed. Forty-nine short and 38 long implants were placed in 30 patients. The mean follow-up time was 5.2 ± 0.8 years after loading, and three implants (two short and one long) failed. The differences in marginal bone loss and implant survival between short and long implants were not statistically significant. Three prosthetic complications occurred. Two prostheses failed, and the survival rate was 95.8%. The immediate loading of short implants is not a risk factor for treatment success. This could be related to the good bone quality and the achievement of adequate primary stability.

Long-Term Outcomes of Immediate Implant Placement Into Infected Sockets in Association With Immediate Loading: A Retrospective Cohort Study.

There is a paucity of studies examining long-term outcomes of immediate loading of dental implants immediately placed into infected sites. This study aims to evaluate long-term outcomes of immediate loading of postextraction implants placed in infected sites. Patients were selected if they had postextraction implants in the anterior maxilla that were inserted in the period from December 2006 to June 2015 and immediately loaded. Information collected about patients included: 1) demographic data; 2) implant details; 3) soft tissue stability; and 4) prosthodontics data. Marginal bone loss (BL) and implant and prosthesis survival rates were calculated. Thirty patients (mean age: 56 years) had 43 implants immediately inserted into infected sites and immediately loaded. Implants were inserted at torque ≥35 Ncm. Mean follow-up time was 6 years (range: 1 to 8 years), and 65% of implants had a follow-up time >5 years. No implant failure occurred, and implant success rate was 93%. Proximal BL was 1.42 mm (range: 0.21 to 5.61 mm). Three prosthetic complications (all fracture of veneer material) occurred. Immediate loading of implants inserted into fresh and infected extraction sockets is not a risk factor for implant survival. However, stability of peri-implant soft and hard tissues indicates the need to take measures that minimize loss.

Immediate Loading of Fixed Complete Denture Prosthesis Supported by 4-8 Implants Placed Using Guided Surgery: A 5-Year Prospective Study on 66 Patients with 356 Implants.

High primary implant stability is considered one of the main factors necessary for achieving predictable treatment outcomes with immediately loaded implant-supported screw-retained fixed complete denture prosthesis (FCDP). To evaluate the 5-year clinical and radiographic outcomes of immediately loaded implants placed in edentulous patients using computer-assisted template-guided surgery to support a FCDP. Patients in need to be restored with a FCDP in the mandible or maxilla were included in this prospective study/ and treated using computer-assisted template-guided surgery. Implant sites were prepared in order to achieve an insertion torque ranging between 35-45 Ncm in the mandible and 45-55 Ncm in the maxilla. A prefabricated screw-retained provisional prosthesis was delivered the day of the surgery. Outcomes were: implant and prosthesis cumulative survival rate (CSR), any complications, and peri-implant marginal bone loss (MBL). Sixty-six patients received 356 implants to support 68 FCDPs. Each patient received 4-8 implants. Seven implants failed in six patients, resulting in a CSR of 98.1%. Two definitive prostheses failed resulting in CSR of 97.1%. Mean MBL of 1.62 ± 0.41 mm was reported at the 5-year follow-up. Five implants (1.4%) showed a mean mesio-distal peri-implant bone loss greater than 3.0 mm and received nonsurgical therapy. immediately loaded implants placed in edentulous patients using computer-assisted template-guided surgery to support a FCDP is a valid treatment concept in the medium term follow-up, for edentulous patients.

Biomechanical analysis of immediately loaded implants according to the “All-on-Four” concept

PurposeThe purpose of this study was to investigate the biomechanical behavior of immediately loaded implants in an edentulous mandible according to the “All-on-Four” concept. MethodsA 3D-finite element model of an edentulous mandible was constructed. Four implants were placed between the bilateral mental foramen according to “All-on-Four” concept. A framework made of titanium or acrylic resin between the bilateral first molars was modeled. Immediate loading and a delayed loading protocol were simulated. A vertical load of 200N was applied at the cantilever or on the abutments region of the distal implants, simulating the absence of a cantilever. ResultsThe peak principal compressive strains in the immediate loading models resulted in 24.0–35.8% and 26.4–39.0% increases compared with the delayed loading models under non-cantilever loading and cantilever loading, respectively. The loading position greatly affected the principal compressive and tensile strain values. The peak principal compressive strains in non-cantilever loading resulted in a 45.3–52.6% reduction compared with those in cantilever loading. The framework material did not influence the peak compressive and tensile strain. The maximum micromotion at the bone–implant interface in the immediate loading models was 7.5–14.4μm. ConclusionsMandibular fixed full-arch prostheses without cantilevers may result in a favorable reduction of the peri-implant bone strain during the healing period, compared with cantilevers. The maximum micromotion was within the acceptable limits for uneventful implant osseointegration in the immediate loading models. Framework material did not play an important role in reducing the peri-implant bone strain and micromotion at the bone–implant interface.

Immediate and Early Loading of Two-Implant-Supported Mandibular Overdentures: Three-Year Report of Loading Results of a Single-Center Prospective Randomized Controlled Clinical Trial.

To report the clinical and radiographic outcomes of a 3-year follow-up of immediately and early loaded two-implant-supported mandibular overdentures. Forty edentulous patients were randomly subdivided into two groups. In the immediate loading group, two Straumann implants were splinted with a Dolder bar and loaded with a mandibular overdenture within the first 48 hours postoperative. In the early loading group, the two implants were loaded with an overdenture 6 weeks postoperative. Standardized intraoral radiographs using a film holder were obtained at 1 month and 3 years. Two independent observers assessed marginal bone loss twice, independently, and analysis of variance (ANOVA) was used to follow up marginal bone level changes. In total, there were 26 remaining patients available at the 3-year followup (15 immediate and 11 early). One implant was lost in the early loading group, and no implants were lost in the immediate loading group. All superstructures and dentures were adequately functional at the 3-year control. Mean radiographic marginal bone loss between baseline and the 3-year follow-up was 0.35 ± 0.63 mm for immediately loaded implants and 0.31 ± 0.96 mm for early loaded implants. The difference between the two groups was not statistically significant (P = .26). Within the limitations of this trial and the short follow-up period and high dropout rate, the immediate loading protocol was found to be comparable in its clinical and radiographic outcomes to the early loading protocol for the two-implant Dolder bar-supported mandibular overdentures.

Clinical guidelines and procedures for provision of mandibular overdentures on 4 mini-dental implants

This article describes the flapless placement of mini-dental implants (MDI) to retain mandibular overdentures. Clinical inclusion/exclusion criteria and clinical protocols for the flapless placement of MDIs and for retrofitting the overdenture are presented. A minimum bone height of 13 mm and a minimal flap are recommended. After drilling, the 4 implants are placed with a self-tapping process. A minimum of 15 Ncm of resistance upon final insertion indicates that immediate loading can be performed. The metal housings with O-rings are incorporated into the prosthesis using autopolymerizing resin. The technique and protocol for immediately loaded 4-mini-implant mandibular overdentures is minimally invasive and cost effective.

EVALUATION OF IMMEDIATELY LOADED KNIFE THREAD IMPLANTS FOR THE REPLACEMENT OF MANDIBULAR SINGLE- ROOTED TEETH (CLINICAL & RADIOGRAPHIC STUDY)

INTRODUCTION: Modern implantology is changing direction towards the development of new implant macrodesigns that are able to provide a high level of physico-mechanical characteristics and can offer a high level of primary implant stability that is important for long-term success of the immediate loading treatment protocols.OBJECTIVES: Clinical and radiographic evaluation of immediately loaded knife thread implants for the replacement of mandibular single- rooted teeth.MATERIALS AND METHODS: This study was conducted on ten adult patients with missing mandibular single rooted teeth. AnyRidge knife threaded tapered implants were inserted and immediately loaded with a non-occluding temporary crowns immediately after implant placement. After 3 months, final crowns were delivered. All implants were followed for 6 months. Clinically, each patient was evaluated for pain, tenderness or discomfort, presence of swelling or infection and mobility of the implant. Radiographically, standardized periapical x-ray films were taken then Image-J processing Program was used for the assessment of marginal bone level and bone density around the implant.RESULTS: In only one case moderate pain, peri-implant infection with suppuration and grade III mobility was registered in the first follow up month, that was regarded as a failure case and the implant was removed, resulting in implant survival rates of 90% after six months. There was a statistically significant increase in bone density around the implants throughout the evaluation period. The mean of peri-implant bone loss increased from immediately post-operative to the 3rd month. This increase was statistically significant. Then there was statistically insignificant decrease from the 3rd to the 6th months. CONCLUSIONS: Immediate non-occlusal loading of knife thread implants for the replacement of mandibular single rooted teeth was a successful treatment procedure, with satisfactory clinical outcomes, good survival rate (90%) and a low incidence of complications.

Immediate Loading of Tapered Implants Placed in Postextraction Sockets and Healed Sites.

The aim of the present study was to compare the survival, stability, and complications of immediately loaded implants placed in postextraction sockets and healed sites. Over a 2-year period, all patients presenting with partial or complete edentulism of the maxilla and/or mandible (healed site group, at least 4 months of healing after tooth extraction) or in need of replacement of nonrecoverable failing teeth (postextraction group) were considered for inclusion in this study. Tapered implants featuring a nanostructured calcium-incorporated surface were placed and loaded immediately. The prosthetic restorations comprised single crowns, fixed partial dentures, and fixed full arches. Primary outcomes were implant survival, stability, and complications. Implant stability was assessed at placement and at each follow-up evaluation (1 week, 3 months, and 1 year after placement): implants with an insertion torque (IT) <45 N·cm and/or with an implant stability quotient (ISQ) <70 were considered failed for immediate loading. A statistical analysis was performed. Thirty implants were placed in postextraction sockets of 17 patients, and 32 implants were placed in healed sites of 22 patients. There were no statistically significant differences in ISQ values between the 2 groups, at each assessment. In total, 60 implants (96.8%) had an IT ≥45 and an ISQ ≥70 at placement and at each follow-up control: all these implants were successfully loaded. Only 2 implants (1 in a postextraction socket and 1 in a healed site, 3.2%) could not achieve an IT ≥45 N·cm and/or an ISQ ≥70 at placement or over time: accordingly, these were considered failed for stability, as they could not be subjected to immediate loading. One of these 2 implants, in a healed site of a posterior maxilla, had to be removed, yielding an overall 1-year implant survival rate of 98.4%. No complications were reported. No significant differences were reported between the 2 groups with respect to implant failures and complications. Immediately loaded implants placed in postextraction sockets and healed sites had similar high survival and stability, with no reported complications. Further long-term studies on larger samples of patients are needed to confirm these results.

Does immediate loading affect clinical and patient-centered outcomes of mandibular 2-unsplinted-implant overdenture? A 2-year within-case analysis

ObjectiveTo provide 2-year clinical- and patient-oriented data with regard to mandibular overdenture assisted by 2 immediately loaded unsplinted implants. Material and methodsIn this pre-post design, Phase-I clinical trial, 18 edentate individuals (62.4±7.7years) received a new set of complete denture. Then, following standard procedures, 3 threaded implants (OsseoSpeed TX™, Dentsply Implants, Mölndal, Sweden) were placed in the mandible in each patient, and locator abutments (Zest Anchors LLC, Escondido, U.S.A.) were inserted on the right and left side implants. The midline implant served as a control for within-patient comparison. The immediate loading was conducted within 24h of surgery. Data were collected at baseline (T0), 12 (T1) and 24 (T2) months after immediate loading. The clinical outcomes included implant survival rate, crestal bone level changes and implant stability. These criteria were assessed through clinical and radiographic examinations as well as resonance frequency analysis. Patient-centered outcomes included patient satisfaction and oral health-related quality of life measured using validated questionnaires. Brunner-Langer approach was used for statistical analysis. ResultsImplant survival rate for immediate loaded implants was 91.7% at 2-year follow-up. None of the unloaded implants failed. There was no statistically significant difference at baseline and follow-ups with regard to clinical outcomes between loaded and unloaded implants. Patient satisfaction and quality of life improved (p<0.0001) from baseline to 2-year follow-up. ConclusionImmediate loading protocol did not negatively affect clinical outcomes, satisfaction and quality of life of patients wearing 2-unsplinted-implant mandibular overdenture for 2 years. This conclusion requires confirmation by randomized control trials. Clinical significance statementMandibular overdenture assisted by two immediately-loaded unsplinted implants is successful treatment based on 2-year clinical and patient-based outcomes.

Effect of two different soft liners and thicknesses mediating stress transfer for immediately loaded 2-implant supported mandibular overdentures: A finite element analysis study

Statement of problemThe use of soft liners as female receptacles for ball attachments retaining immediately loaded implant overdenture has been recommended to enhance osseointegration and provide a shock absorbing effect. However, which liner and which thickness is still unclear. PurposeThe purpose of this finite element analysis (FEA) study was to evaluate the effect of a 2- and 4-mm thickness of thermoplastic resin (TRL) and silicone-based liners (SBL) on the displacement and stresses transmitted to immediately loaded implants retaining a mandibular overdenture. Material and methodsFour 3-dimensional (3D) FEA models of a mandibular implant overdenture retained by 2 ball attachments (2 models for each lining material with 2- or 4-mm liner thicknesses) were developed. Implants were placed in the canine regions and surrounded by a 1-mm cylinder of immature bone simulating immediate loading. A vertical and an oblique load of 150 N were applied in the right premolar molar regions. Stresses and displacement were set as output variables. ResultsReplacing the TRL by the SBL was associated with a decrease in stresses by 73% and in displacement by at least 46%. Increasing the thickness of any liner decreases stresses by 45% during vertical loading and by 25% during oblique loading and decreases displacement by 61.5% during vertical loading and by an average of 32.5% during oblique loading. None of the liners exceeded the experimental risk limits for micromotion at the bone-implant interface (50 μm). ConclusionIn immediately loaded mandibular implant overdentures, both SBL and TRL decrease the micromotion of implants and the stresses at the bone-implant interface. However, SBL is more effective. The thickness of both liners seems to play a major role in decreasing the stresses and displacement of periimplant tissues.

Computer-aided flapless implant surgery and immediate loading. A technical note

The aim of the present technical note was to describe a prosthetic technique developed to increase the predictability of immediately loaded implants supporting a fixed prosthesis after computer-aided template-guided flapless implant placement. During a 2-year period, eight patients presenting partial edentulism underwent computer-aided template-guided implant placement. The presented technique was used during the prosthetic procedures to directly transfer the data obtained with the facebow to the surgical environment, allowing for accurate repositioning of the temporary prosthesis on the implants as previously planned with the digital software. A total of 78 dental implants were immediately loaded with an implant-supported fixed prosthesis after flapless template-guided implant placement. A survival and success rate of 100% was reported after a mean follow-up of 1year from the prosthetic loading. Neither major complications nor dropouts were observed during the healing time. From both clinical and radiological evaluations, implants appeared stable with no signs of soft tissue inflammation or infection and no evidence of pathological peri-implant bone resorption. The proposed technique associated with computer-aided implant placement and immediate loading protocol provided a high implant and prosthetic survival and success rate. No complications were reported during the recalls, suggesting predictability and reliability of the present technique over a short-term period.

Evaluation of the Effect of Platelet-Released Growth Factor and Immediate Orthodontic Loading on the Removal Torque of Miniscrews.

The purpose of this study was to evaluate the effect of platelet-released growth factor (PRGF) and immediate orthodontic forces on the removal torque of miniscrews. This study was conducted on three male dogs aged 6 to 8 months with a body weight of 17.6 to 18.4 kg. Sixty miniscrews were inserted in the posterior aspect of the femur. There were four groups, including loaded miniscrews with application of PRGF, unloaded miniscrews without application of PRGF, unloaded miniscrews with PRGF, and loaded miniscrews without PRGF. Twenty miniscrews were inserted in the femoral bone of one foot of each dog, including all the aforementioned subgroups. After 12 weeks, the miniscrews were removed by a removal torque tester device and measured in newton centimeters. The mean removal torque values in four groups of immediately loaded screws with PRGF, unloaded screws with PRGF, immediately loaded screws without PRGF, and unloaded screws without PRGF were 19.68, 21.74, 13.65, and 15.46 Ncm, respectively. It was shown that the mean removal torque value for the group with PRGF was significantly higher than that in the other groups (P = .0001). Although there was a tendency toward a decrease in removal torque value with immediate loading, it was not statistically significant (P = .21). According to the results of this study, applying PRGF with miniscrews increased their stability, but the delivery of immediate force on miniscrews had no effect on the miniscrews' stability.

Changes in alveolar bone density around immediate functionally and nonfunctionally loaded implants

Statement of problemFew studies compare the radiographic changes in bone density associated with immediate implant loading protocols. PurposeThe purpose of this longitudinal study was to quantitatively assess radiographic changes in alveolar bone density around immediate functionally and nonfunctionally loaded implants. Material and methodsA prospective longitudinal study was conducted in which 20 participants with partially edentulous mandibles received implants that were immediately loaded either functionally (IFL) or nonfunctionally (INFL). Standardized intraoral periapical radiographs were made at baseline, 3, and 6 months. These were digitized and analyzed using the histogram tool of the GNU Image Modulation Program for changes in alveolar bone density at crestal and lateral apical levels around the implant. ResultsAn increase in the mean lateral apical pixel grayscale values of 4.68 ±0.80 at 3 months and 4.15 ±0.29 at 6 months was observed with IFL, while INFL demonstrated an increase of 5.66 ±0.53 at 3 months and 6.07 ±0.59 at 6 months. A decrease in the mean crestal pixel grayscale values of -24.40 ±7.41 with IFL and -16.86 ±5.14 with INFL was found from baseline to 3 months. ConclusionsOn the basis of this longitudinal study, it was concluded that immediate loading stimulated alveolar bone formation at 6 months after implant placement. The immediate functional loading of implants resulted in a significantly greater degree of bone demineralization at the alveolar crest from implant placement up to 3 months compared with immediate nonfunctional loading.

The effects of bone density and crestal cortical bone thickness on micromotion and peri-implant bone strain distribution in an immediately loaded implant: a nonlinear finite element analysis.

PurposeThis study investigated the effects of bone density and crestal cortical bone thickness at the implant-placement site on micromotion (relative displacement between the implant and bone) and the peri-implant bone strain distribution under immediate-loading conditions.MethodsA three-dimensional finite element model of the posterior mandible with an implant was constructed. Various bone parameters were simulated, including low or high cancellous bone density, low or high crestal cortical bone density, and crestal cortical bone thicknesses ranging from 0.5 to 2.5 mm. Delayed- and immediate-loading conditions were simulated. A buccolingual oblique load of 200 N was applied to the top of the abutment.ResultsThe maximum extent of micromotion was approximately 100 μm in the low-density cancellous bone models, whereas it was under 30 μm in the high-density cancellous bone models. Crestal cortical bone thickness significantly affected the maximum micromotion in the low-density cancellous bone models. The minimum principal strain in the peri-implant cortical bone was affected by the density of the crestal cortical bone and cancellous bone to the same degree for both delayed and immediate loading. In the low-density cancellous bone models under immediate loading, the minimum principal strain in the peri-implant cortical bone decreased with an increase in crestal cortical bone thickness.ConclusionsCancellous bone density may be a critical factor for avoiding excessive micromotion in immediately loaded implants. Crestal cortical bone thickness significantly affected the maximum extent of micromotion and peri-implant bone strain in simulations of low-density cancellous bone under immediate loading.

A Randomized Case-Series Study Comparing the Stability of Implant with Two Different Surfaces Placed in Fresh Extraction Sockets and Immediately Loaded.

Background. Hydrophilic and moderately rough implant surfaces have been proposed to enhance the osseointegration response. Aim. The aim of this study was to compare early changes of stability for two implants with identical macrodesign but with different surface topographies. Materials and Methods. In 11 patients, a total of 22 implants (11 bimodal (minimally rough, control) and 11 proactive (moderately rough and hydrophilic, test), Neoss Ltd., Harrogate, UK) were immediately placed into fresh extraction sockets and immediately loaded. The peak insertion torque (IT) was measured in Ncm at placement. Resonance Frequency Analysis (RFA) measurements were made at baseline and 2, 4, 6, and 12 weeks after surgery. Results. The two implant types showed similar IT and RFA values at placement (NS). A dip of RFA values after 2 weeks followed by an increase was observed, where the test implant showed a less pronounced decrease and a more rapid recovery than the control implant. The test implants were significantly more stable than the control ones after 12 weeks. Conclusions. The results from the present study indicated that the hydrophilic and rougher test implant was more resistant to immediate loading and showed a significantly higher stability than the smoother control implant after 12 weeks.

The feasibility of immediately loading dental implants in edentulous jaws.

PurposeImmediate loading of dental implants has been proved to be feasible in partially edentulous jaws. The purpose of this retrospective investigation was to assess the feasibility of immediately loading dental implants in fully edentulous jaws.MethodsA total of 24 patients aged between 53 and 89 years received a total of 154 implants in their edentulous maxillae or mandibles. Among the implants, 45 were set in fresh extracted sockets and 109 in consolidated alveolar bones. The implants were provisionally managed with chair-side made provisional resin bridges and exposed to immediate loading. Implants were followed up for 1–8 years, including radiographic imaging. Marginal bone levels were evaluated based on radiographic imaging.ResultsA total of 148 out of the 154 implants survived over the follow-up period of 1 to 8 years, giving a survival rate of 96%. The time or region of the implantation, the pre-implant augmentation, and the length and diameter of the implants had no statistically significant influence on the survival or the success rate. The marginal bone level remained stable with only minimal loss of 0.3 mm after 60 months of loading.ConclusionsWithin the limitations of this study, immediate loading is feasible for dental implants in edentulous jaws.

A Systematic Review on Immediate Loading of Implants Used to Support Overdentures Opposed by Conventional Prostheses: Factors That Might Influence Clinical Outcomes.

Different treatment protocols in terms of number, diameter, and suprastructure design have been proposed for immediately loaded implants that are used to support mandibular overdentures opposed by maxillary conventional dentures. The aim of this study was to investigate the influence of these protocols on survival rates as well as clinical and prosthodontic outcomes. Several electronic databases were searched for all relevant articles published from 1966 to June 2014. Only randomized controlled trials and prospective studies with a minimum follow-up of 12 months were selected. The primary outcomes of interest were the success and survival rates of the implants. Prosthodontic complications were also evaluated. Fourteen studies fulfilled the inclusion criteria. Of the studies identified, nine were randomized controlled trials and five were prospective studies. The mean follow-up period was 3 years or less for the vast majority of the studies. The reported survival and success rates were comparable to that of conventional loading for most of the included studies. No specific immediate loading protocol seemed to perform better in terms of clinical and prosthodontic outcomes. Immediate loading protocols of mandibular overdentures seem to be a viable alternative to conventional loading. It was not possible to recommend a specific treatment protocol related to the number, diameter of the implants, and attachment system used. Long-term, well-designed studies comparing different immediate loading modalities could help to establish a protocol that delivers the most clinically predictable, efficient, and cost-effective outcome for edentulous patients in need of implant overdentures.

From Guided Surgery to Final Prosthesis with a Fully Digital Procedure: A Prospective Clinical Study on 15 Partially Edentulous Patients.

Scope. To demonstrate guided implant placement and the application of fixed, implant-supported prosthetic restorations with a fully digital workflow. Methods. Over a 2-year period, all patients with partial edentulism of the posterior maxilla, in need of fixed implant-supported prostheses, were considered for inclusion in this study. The protocol required intraoral scanning and cone beam computed tomography (CBCT), the superimposition of dental-gingival information on bone anatomy, surgical planning, 3D-printed teeth-supported surgical templates, and modelling and milling of polymethylmethacrylate (PMMA) temporaries for immediate loading. After 3 months, final optical impression was taken and milled zirconia frameworks and 3D-printed models were fabricated. The frameworks were veneered with ceramic and delivered to the patients. Results. Fifteen patients were selected for this study. The surgical templates were stable. Thirty implants were placed (BTK Safe®, BTK, Vicenza, Italy) and immediately loaded with PMMA temporaries. After 3 months, the temporaries were replaced by the final restorations in zirconia-ceramic, fabricated with a fully digital process. At 6 months, none of the patients reported any biological or functional problems with the implant-supported prostheses. Conclusions. The present procedure for fully digital planning of implants and short-span fixed implant-supported restorations has been shown to be reliable. Further studies are needed to validate these results.

Planning Implant Placement on 3D Stereolithographic Models Applied with Immediate Loading of Implant-Supported Hybrid Prostheses After Multiple Extractions: A Case Series

The aim of this noninterventional, retrospective case series was to evaluate the outcome of immediately loaded implants in patients with failing dentitions that require bone tabling using a bone reduction guide and a surgical guide manufactured directly on three-dimensional (3D) stereolithographic models. Consecutive patients with failing dentition and at least two remaining teeth who were treated in a single center between December 14, 2009 and September 23, 2013 were eligible. All patients receiving implants loaded with a hybrid prosthesis on the same day as extraction with their surgery planned on 3D models and performed using a surgical guide manufactured in a laboratory on the planning model were included. Patients who had undergone bone grafting procedures were excluded. Descriptive statistical analyses of available data were performed, including life-table calculations to derive a cumulative survival rate (CSR). Two hundred twenty-eight patients (105 females and 123 males) received 1,657 implants (NobelActive) in 321 arches, in most cases 5 implants (range, 5 to 7) per arch. Ten preexisting implants were used. The mean insertion torque was 60.02 ± 13.1 Ncm (range, 15 to 75 Ncm). The definitive abutment was placed on the same day as surgery in all cases, and the definitive prosthesis (n = 304) was delivered after a mean of 7.9 ± 2.6 months. All implants were followed for 20.01 ± 11.3 months (range, 0 to 52 months) from implant insertion. Four implants (3 patients) had delayed loading, and one implant was left as a sleeping implant. Eight implants among six patients failed, two of the implants after prosthesis delivery. The CSR of the placed implants was 99.4% at implant level and 96.2% at patient level. Planning on 3D models to remove bone and place implants using custom-made bone reduction and surgical guides with immediate loading on the same day as extraction of remaining teeth was safe and effective for implant survival and rehabilitation of patients with periodontitis and failing dentition.