A randomized controlled clinical trial comparing guided with nonguided implant placement: A 3-year follow-up of implant-centered outcomes.

STATEMENT OF PROBLEM: Implant-based prosthetic solutions can be time consuming. If implants can be placed successfully with a guide, surgery time can be reduced. PURPOSE: The purpose of this randomized controlled clinical trial was to assess implant outcomes, both clinical and radiological, comparing guided with nonguided implant placement after 3 years of follow-up. MATERIAL AND METHODS: A total of 314 implants were placed in 72 jaws (60 participants). The jaws were randomly assigned to 1 of the 6 treatment groups: Materialise Universal/mucosa (Mat Mu), Materialise Universal/bone (Mat Bo), Facilitate/mucosa (Fac Mu), Facilitate/bone (Fac Bo), freehand navigation (Freehand), and a pilot-drill template (Templ). Radiographic and clinical parameters (bone loss, pocket probing depth, bleeding on probing, and plaque scores) were recorded at the time of implant placement, prosthesis installment (baseline), and 1-year, 2-year, and 3-year follow-up. Analysis was performed using a linear mixed model, and correction for simultaneous hypothesis was made according to Sidak (α=.05). RESULTS: Three participants left the study before the 3-year follow-up; hence, 302 implants in 69 jaws were included in this study. None of the implants failed. The mean marginal bone loss after the third year of loading was 0.7 ±1.3 mm for the guided surgery group and 0.5 ±0.6 mm for the control group. No significant intergroup or follow-up period differences were observed (P>.05). In the guided surgery groups, the mean number of surfaces with bleeding on probing and plaque at 3-year follow-up was 1.7 ±1.5 and 1.7 ±1.7, respectively; for the control groups, this was 1.6 ±1.4 and 1.6 ±1.6, respectively. The mean pocket probing depth was 3.0 ±1.3 mm for the guided group and 2.6 ±1.0 mm for the control group. No significant differences were found (P>.1). CONCLUSIONS: Within the limitation of this study, no statistically significant differences could be found between the guided group and the control group at the 3-year follow-up.

Randomized controlled trial comparing immediate loading with conventional loading using cone-anchored implant-supported screw-retained removable prostheses: A 2-year follow-up clinical trial.

STATEMENT OF PROBLEM: Implant-based prosthetic solutions can be time consuming. If implants can be loaded immediately, treatment time can be reduced. PURPOSE: The purpose of this prospective randomized controlled trial was to monitor the survival rate of Ankylos implants, comparing conventional with immediate loading by using abutments with the SynCone concept for screw-retained removable prostheses in the edentulous maxilla. MATERIAL AND METHODS: A total of 90 implants were placed in 15 study participants. The participants were randomly assigned to the immediate or conventional loading treatment group. Radiographic and clinical parameters were recorded at the time of permanent prosthesis installment and at 1- and 2-year follow-up examinations, and participants' satisfaction was measured by using questionnaires before and after prosthesis installation. A linear mixed model was used to measure differences. RESULTS: One implant in the conventional group was lost during abutment placement; hence, 89 implants could be followed for 2 years. Approximately 90% of these implants showed no bone loss or even bone gain at 1 and 2 years follow-up. Mean values for the immediate group were, respectively, 0.09 ±0.35 mm and 0.13 ±0.38 mm and 0.01 ±0.41 mm and -0.06 ±0.32 mm for the conventional method. No significant differences (P=.053) were found in bone level alterations between the groups. For all participants, the mean number of surfaces (4 per implant) with bleeding on probing (BoP) and plaque were 0.76 ±0.81 and 0.16 ±0.42 at 1 year follow-up and 0.44 ±0.66 and 0.02 ±0.15, respectively, at the second-year follow-up. The mean pocket probing depths were 2.05 ±0.54 mm at 1 year and 2.18 ±0.64 mm at 2 years. For both groups, a significant rise in satisfaction and quality of life was observed (P≤.001) at 1 and 2 years compared with pretreatment. CONCLUSIONS: Ankylos implants placed in the edentulous maxilla, immediately or conventionally loaded by a detachable prosthesis, showed favorable bone-level preservation after 2 years of follow-up. No significant differences could be found between the immediate and conventional groups. A significant increase in quality of life was observed for both loading modes.

Relationship of implant stability and bone density derived from computerized tomography images.

BACKGROUND AND PURPOSE: Implant stability is one of the most important factors influencing osseointegration. Using stereolithographical guides for maximizing precision, this study aimed at investigating the relationship between implant stability and bone density derived from computerized tomography analysis. MATERIALS AND METHODS: One hundred ninety-five implants were placed in 48 patients using digitally designed stereolithographical surgical guides. Ninety-five implants were placed using a mucosa supported guide and 100 implants were placed using a bone supported guide. Implant stability was measured by means of resonance frequency analysis (RFA) and damping capacity assessment (Periotest, PTV). Bone density (Hounsfield units) was measured at different regions of interest (ROI) and cortex thickness was measured around each implant. RESULTS: Implant stability correlated significantly with the different ROI. The best correlation for RFA was obtained for the spongious bone ROI (r = .64) and PTV best correlated with the coronal cortex density (r = -.41). Shorter implants (9 mm) had a significantly lower primary stability than longer implants (11, 13, 15 mm). Primary stability was also significantly higher in 4 mm diameter implants than in 3.5 mm diameter implants. A formula for the prediction of primary stability based on the different variables investigated was developed. CONCLUSIONS: Bone density and cortex thickness have a significant influence on implant primary stability. Longer and wider implants reached higher primary stability than shorter and narrower implants. These correlations lose their significance after osseointegration has taken place. Implant stability can be predicted based on an preoperative analysis of bone characteristics.

The fate of buccal bone around dental implants. A 12-month postloading follow-up study.

INTRODUCTION AND AIM: Buccal bone thickness is considered to be an important factor during implant surgery. Its resorption might have an effect on the soft tissue stability and eventually on implant survival. This study aimed to investigate the resorption of the buccal bone over the first 12 months after implant loading. MATERIALS AND METHODS: Twenty-four subjects (47 implants) were included. The buccal bone thickness was measured during implant surgery at several distances from the implant shoulder using a specifically designed device which allows buccal bone thickness measurements without the elevation of a muco-periostal flap. These measurements were repeated after 12 months of loading. Sixteen implants were placed flapless and 31 with the elevation of a flap. Of the latter, 19 were placed following a one-stage protocol and 12 following a two-stage protocol. RESULTS: The mean reduction in buccal bone thickness, when all groups pooled, was 0.26, 0.36, 0.35 and 0.27 mm at the shoulder and 2, 4 and 6 mm apically. Implants with initial bone thickness <1mm (thin buccal plate) did not lose significantly more bone than those with an initial thickness ≥1mm (thick bone plate) except in the 'open-flap, one-stage' group (P = 0.009). A flapless procedure leads to less bone resorption compared to an open-flap procedure (P = 0.03). However, the number of surgeries (one stage vs. two stages) did not influence the rate of bone resorption (P = 0.23). CONCLUSION: Within the limitations of this study, one might question the necessity of having a thick bone plate at the vestibular site of the implant.

Guided Implant Surgery in the Edentulous Maxilla: A Systematic Review.

PURPOSE: This systematic review verified the usefulness/limitations of static surgical guides during implant surgery in the edentulous maxilla. The PICO question was: "Does the use of digitally generated surgical guides vs conventional techniques affect the following outcomes: surgical complications, implant complications, prosthesis complications, implant survival, prosthesis survival, economics, patient satisfaction, and maintenance intervention?" MATERIALS AND METHODS: The electronic searches retrieved 2,588 unique articles from which eventually 36 full-text articles were read for eligibility. Because no randomized controlled clinical trials could be found, the PICO question had to be reformulated, now only looking to the outcome of digitally generated surgical guides without comparison with conventional techniques. RESULTS: Although long-term data are lacking, the outcome of implants placed with a static guide and of the prosthetic reconstruction seems similar to that expected from conventional techniques. The number of surgical complications with guided surgery is negligible. Guided flapless implant surgery offers slightly more comfort for the patient; however, the economic benefits are unclear. CONCLUSION: Implant therapy via static surgical guides in the maxilla is predictable, with slightly more comfort for the patient but with only minor economic advantages.

Accuracy and patient-centered outcome variables in guided implant surgery: a RCT comparing immediate with delayed loading.

AIM: To assess the accuracy and patient-centered outcome of a novel guided surgery system for placing implants in an edentulous maxilla. MATERIAL AND METHODS: Fifteen consecutive patients with sufficient bone to place six implants in the maxilla were randomly assigned to the immediate loading (with delivery of the final prosthesis within 24 h) or the delayed loading treatment group. Accuracy was assessed by matching the planning CT with a postoperative CBCT. Patient-centered outcome measures were the Dutch version of the McGill Pain Questionnaire (MPQ-DLV), the health-related quality of life instrument (HRQOL), visual analog scales (VAS), the duration of the procedure, and the analgesic doses taken each day. RESULTS: A mean deviation was found at the entry point of 0.9 mm (range: 0.1-4.5, median 0.8) and of 1.2 mm (range: 0.2-4.9, median 1.1) at the apex, and an angular deviation of 2.7° (range: 0.0-6.6°, median 2.3) was observed. The mean vertical deviation was 0.5 mm (range: 0.0-3.2, median 0.4), and in a horizontal direction, this was 0.7 mm (range: 0.1-3.1, median 0.6). The mean deviation in mesio-distal direction was 0.5 mm (range: 0.0-2.3, median 0.4) and in bucco-lingual direction 0.5 mm ± 0.4 (range: 0.0-2.2, median 0.3). No statistical differences could be shown between treatment groups on pain response (MPQ-DLV), treatment perception (VAS), number or kind of pain killers, or for the HRQOLI instrument. CONCLUSION: The accuracy of a novel CT-based guide is comparable to the accuracy data of other systems. Within the limitations of this study, no difference could be found in patient-centered outcome variables after immediate or delayed loading.

Computer-supported implant planning and guided surgery: a narrative review.

AIM: To give an overview of the workflow from examination to planning and execution, including possible errors and pitfalls, in order to justify the indications for guided surgery. MATERIAL AND METHODS: An electronic literature search of the PubMed database was performed with the intention of collecting relevant information on computer-supported implant planning and guided surgery. RESULTS: Currently, different computer-supported systems are available to optimize and facilitate implant surgery. The transfer of the implant planning (in a software program) to the operative field remains however the most difficult part. Guided implant surgery clearly reduces the inaccuracy, defined as the deviation between the planned and the final position of the implant in the mouth. It might be recommended for the following clinical indications: need for minimal invasive surgery, optimization of implant planning and positioning (i.e. aesthetic cases), and immediate restoration. CONCLUSIONS: The digital technology rapidly evolves and new developments have resulted in further improvement of the accuracy. Future developments include the reduction of the number of steps needed from the preoperative examination of the patient to the actual execution of the guided surgery. The latter will become easier with the implementation of optical scans and 3D-printing.

Digital technologies to support planning, treatment, and fabrication processes and outcome assessments in implant dentistry. Summary and consensus statements. The 4th EAO consensus conference 2015.

OBJECTIVE: The task of this working group was to assess the existing knowledge in computer-assisted implant planning and placement, fabrication of reconstructions applying computers compared to traditional fabrication, and assessments of treatment outcomes using novel imaging techniques. MATERIAL AND METHODS: Three reviews were available for assessing the current literature and provided the basis for the discussions and the consensus report. One review dealt with the use of computers to plan implant therapy and to place implants in partially and fully edentulous patients. A second one focused on novel techniques and methods to assess treatment outcomes and the third compared CAD/CAM-fabricated reconstructions to conventionally fabricated ones. RESULTS: The consensus statements, the clinical recommendations, and the implications for research, all of them after approval by the plenum of the consensus conference, are described in this article. The three articles by Vercruyssen et al., Patzelt & Kohal, and Benic et al. are presented separately as part of the supplement of this consensus conference.

The accuracy of guided surgery via mucosa-supported stereolithographic surgical templates in the hands of surgeons with little experience.

OBJECTIVES: This prospective study analyzed the accuracy of implant placement with mucosa-supported stereolithographic guides, executed by inexperienced surgeons supervised by an experienced colleague. MATERIAL AND METHODS: For the accuracy analysis, 75 OsseoSpeed implants™, placed in 17 fully edentulous jaws (16 patients) using a mucosa-supported stereolithographic guide (IMPLANT SAFE Guide, DENTSPLY Implants) and the Facilitate™ protocol, were included. DICOM images of the pre-surgical planning and the post-surgical CBCT were matched using the Mimics(®) software (Materialise Dental). These data were compared with the data (12 jaws, 52 implants) of an experienced surgeon (Vercruyssen et al. Journal of Clinical Periodontology 2014; doi:10.1111/jcpe.12231). RESULTS: The global deviation at the coronal and apical point was 0.9 mm (SD 0.5) and 1.1 mm (SD 0.5), respectively. Depth deviations were 0.5 mm (SD 0.5) and 1.1 mm (SD 0.5), respectively, and the angular deviation was 2.8° (SD 1.5°). These deviations were statistically not inferior to the deviations of the experienced surgeon and also within the range of deviations reported by several systematic reviews. CONCLUSION: Within the limitations of this study and for the above-mentioned surgical protocol, inexperience of the surgeon had no influence on the accuracy of implant placement in fully edentulous jaws, when all steps needed for the procedure are supervised by experienced dentists.

Implant- and patient-centred outcomes of guided surgery, a 1-year follow-up: An RCT comparing guided surgery with conventional implant placement.

AIM: To assess, in a randomized study, the implant (clinical and radiological) and patient outcomes of guided implant placement at 1-year follow-up, compared to conventional implant treatment. MATERIAL AND METHODS: A total of 314 were placed in 59 patients, randomly assigned to one of the treatment groups. Radiographic and clinical parameters were recorded at the time of implant placement, prosthesis instalment (baseline) and at 1-year follow-up. Patient satisfaction was measured with the oral health-related quality of life instrument (OHIP-49). RESULTS: No implants were lost. The mean marginal bone loss after the first year of loading was 0.04 mm (SD 0.34) for the guided surgery and 0.01 mm (SD 0.38) for the control groups. In the guided surgery groups, the mean number of surfaces with BOP and plaque at 1-year follow-up was 1.41 (SD 1.25) and 1.10 (SD 1.22), for the control groups this was, respectively, 1.37 (SD 1.25) and 1.77 (SD 1.64). The mean pocket probing depth was 2.81 mm (SD 1.1) for the guided, and 2.50 mm (SD 0.94) for the control groups. For all treatment groups, a significant improvement in quality of life was observed at 1-year follow-up (p ≤ 0.01), no differences between groups were observed. CONCLUSION: Within the limitations of this study, no difference could be found at 1-year follow-up between the implant and patient outcome variables of guided or conventional implant treatment.

Different techniques of static/dynamic guided implant surgery: modalities and indications.

For computer-guided surgery a static surgical guide is used that transfers the virtual implant position from computerized tomographic data to the surgical site. These guides are produced by computer-aided design/computer-assisted manufacture technology, such as stereolithography, or manually in a dental laboratory (using mechanical positioning devices or drilling machines). With computer-navigated surgery the position of the instruments in the surgical area is constantly displayed on a screen with a three-dimensional image of the patient. In this way, the system allows real-time transfer of the preoperative planning and visual feedback on the screen. A workflow of the different systems is presented in this review.

Guided surgery: accuracy and efficacy.

Different computer-assisted implant-placement procedures are currently available. These differ in software, template manufacture, guiding device, stabilization and fixation. The literature seems to indicate that one has to accept a certain inaccuracy of ±2.0 mm, which seems large initially but is clearly smaller than for nonguided surgery. A reduction of accuracy to below 0.5 mm seems extremely difficult. A common shortcoming identified in the studies included in this review is inconsistency in how clinical data and outcome variables are reported. Another limitation is the small number of comparative clinical studies. In order to find the best guiding system or the most important parameters for optimal accuracy, more randomized clinical trials are necessary. Information on cost-effectiveness and patient-centered evaluations (i.e. questionnaires and interviews) must also be included.

An RCT comparing patient-centred outcome variables of guided surgery (bone or mucosa supported) with conventional implant placement.

AIM: To assess in a randomized study the patient-centred outcome of two guided surgery systems (mucosa or bone supported) compared to conventional implant placement, in fully edentulous patients. MATERIAL AND METHODS: Fifty-nine patients (72 jaws) with edentulous maxillas and/ or mandibles, were consecutively recruited and randomly assigned to one of the treatment groups. Outcome measures were the Dutch version of the McGill Pain Questionnaire (MPQ-DLV), the Health-related quality of life instrument (HRQOL), visual analogue scales (VAS), the duration of the procedure, and the analgesic doses taken each day. RESULTS: Three hundred and fourteen implants were placed successfully. No statistical differences could be shown between treatment groups on pain response (MPQ-DLV), treatment perception (VAS) or number or kind of pain killers. For the HRQOLI-instrument, a significant difference was found between the Materialise Mucosa and Materialise Bone group at day 1 (p = 0.02) and day 2 (p = 0.01). For the duration of the surgery, a statistical difference (p = 0.005) was found between the Materialise mucosa and the Mental group, in favour of the first. CONCLUSION: In this study little difference could be found in the patient outcome variables of the different treatment groups. However there was a tendency for patients treated with conventional flapped implant placement to experience the pain for a longer period of time.

A randomized clinical trial comparing guided implant surgery (bone- or mucosa-supported) with mental navigation or the use of a pilot-drill template.

AIM: To assess the accuracy of guided surgery (mucosa and bone-supported) compared to mental navigation or the use of a surgical template, in fully edentulous jaws, in a randomized controlled study. MATERIAL AND METHODS: Fifty-nine patients (72 jaws), requiring four to six implants (maxilla or mandible), were consecutively recruited and randomly assigned to one of the following treatment groups; guidance via Materialise Universal(®)/mucosa, Materialise Universal(®)/bone, Facilitate™/mucosa, Facilitate™/bone, or mental navigation or a pilot-drill template. The precision was assessed by matching the planning computed tomography (CT) with a post-operative cone beam CT. RESULTS: A significant lower mean deviation at the entry point (1.4 mm, range: 0.3-3.7), at the apex (1.6 mm, range: 0.2-3.7) and angular deviation (3.0°, range: 0.2-16°) was observed for the guiding systems when compared to mental navigation (2.7 mm, range: 0.3-8.3; 2.9 mm, range: 0.5-7.4 and 9.9°, range: 1.5-27.8) and to the surgical template group (3.0 mm, range: 0.6-6.6; 3.4 mm, range: 0.3-7.5 and 8.4°, range: 0.6-21.3°). Differences between bone and mucosa support or type of guidance were negligible. Jaw and implant location (posterior-anterior, left-right), however, had a significant influence on the accuracy when guided. CONCLUSION: Based on these findings, guided implant placement appears to offer clear accuracy benefits.

Tolerance within the sleeve inserts of different surgical guides for guided implant surgery.

OBJECTIVES: Recently, guided implant surgery has been introduced and several studies verified its accuracy. While those studies reported on the accuracy of the entire procedure, this experiment wanted to evaluate the degree of deviation that can occur during the drilling procedure alone, due to the tolerance of the drill in the sleeve insert. MATERIAL AND METHODS: Drilling was executed in a plexi-glass box with a maximal inclination of the drills within the sleeve insert. Different sleeve inserts, sleeve positions, sleeve heights, sleeve insert heights and diameters were evaluated. RESULTS: The two tested sleeve inserts gave a maximum deviation in angulation of 5.2° and a maximum horizontal deviation of 1.3 mm at the implant shoulder and 2.4 mm at the apex for a 13 mm implant. These deviations decreased if the distance of the sleeve above the plexi-glass box became smaller and hand hold sleeve inserts gave less deviation than drill hold sleeve inserts. The deviation increased by longer implant length, larger drill key diameter, shorter sleeves and/or drill key heights. CONCLUSIONS: For a minimal deviation during the surgery with a stereolithographic guide, it is very important to use the drill in a centric position, parallel to the cylinder. The use of longer drill keys and sleeves are critical for optimal accuracy.

Risk factors and indications of orthodontic temporary anchorage devices: a literature review.

AIMS: The aims of this review are twofold, firstly, to give an overview of the general and local risk factors when using temporary anchorage devices (TADs) and the prerequisites for placement and, secondly, to illustrate the orthodontic indications of various TADs. METHODS: The PubMed database was searched for original articles on: 'orthodontics and miniscrews/mini-implants/ miniplates/temporary anchorage devices/titanium screws/skeletal anchorage', 'miniscrews/mini-implants/miniplates and risk factors/biomechanics/placement procedure'. Only articles published between 2001 and December 2007 were used. In addition, each article was hand searched for references that may have been missed by the PubMed search. RESULTS: General risk factors are factors concerning general health. Bone quality and oral hygiene are local risk factors. Aspects of the placement procedure discussed were: primary stability, loading protocols, pre-drilling diameter and whether or not to make an intra-oral incision. A selection of published case reports is given to illustrate some orthodontic indications of TADs. CONCLUSIONS: Temporary anchorage devices have a place in modern orthodontics. Careful treatment planning involving radiographic examination is essential. Consultation with an oral surgeon is advisable if a soft tissue flap is required. Excellent patient compliance, particularly avoidance of inflammation around the implant, is an important consideration for successful use of TADs.