Immediately loaded CAD-CAM manufactured fixed complete dentures using flapless implant placement procedures: a cohort study of consecutive patients

Surgical guides for flapless dental implant placement and immediate definitive prosthesis installation by using selective laser melting and sintering for 3D metal and polymer printing: A clinical report

Integration between the phases of computer-based guided dental implant surgery can be used to optimize oral rehabilitation. Two new surgical guides prepared by using the 3D metal and polymer printing technology are presented for immediate implant loading and definitive fixed prosthesis construction in flapless dental implant surgery. Nine implants and 2 fixed prostheses were installed in 2 completely edentulous adult patients by using a metallopolymer surgical guide with a metal central bar attached to a polymer seal or a metal guide. Virtual planning was used to design the 3D printed surgical guides, which were then constructed by using selective laser sintering (SLM) and selective laser melting (SLS). The 3D printed surgical guides oriented the surgical placement of the implants and were welded to the abutments and attached to the denture framework. The technique allowed implants and prostheses to be installed on the same day.

Guided Dental Implant Surgery: Systematic Review

Among the common procedures in clinical practice in the field of dentistry is prosthetic rehabilitation through the insertion of dental implants. In order to obtain the best aesthetic and functional results, the oral surgeon who deals with implantology must be able to position the dental implants correctly; a crucial role is therefore played by the diagnostic and treatment planning phases, where attention must be paid to anatomical constraints and prosthetic constraints in the alveolar bone site. The parameters, such as bone quality, bone volume, and anatomical restrictions, can be processed and simulated using implant planning software. The simulation of the virtual positioning of the implant can lead to the construction of a three-dimensional model of the implant positioning guide, which can be used during the implant surgery. The aim of this systematic review is to evaluate survival rates, early and late failure rates, peri-implant bone remodeling, and possible implant-prosthetic complications related to implants placed using digitally designed surgical guides. This systematic review was written following the indications of PRISMA and envisaged the use of 3 databases: Scopus, PubMed, and Cochrane Library. Results: Only 9 of the 2001 records were included, including 2 retrospective studies and 7 prospective studies. Conclusion: On the basis of the studies selected in this review, it can be seen that the implant survival obtained with the use of guided implant surgery shows high percentages. Many recorded failures occurred early, due to a lack of osseointegration, and the variables that come into play in the survival of the implants are many.

Material Extrusion Based Fabrication of Surgical Implant Template and Accuracy Analysis

An implant template with great precision is significantly critical for clinical application. Currently, the application of an immediate implant remains limited by the deviations between the planned and actual achieved positions and long periods required for preparation of implant templates. Material Extrusion (MEX), as one kind of 3D printing method, is well known for its low cost and easy operation. However, the accuracy of the implant template printed by MEX has not been fully researched. To investigate the accuracy and feasibility of in vitro computer-guided surgery assisted with a MEX printed template, unidentified plaster samples missing a maxillary molar are digitalized. Mimics software (Materialise, Leuven, Belgium) is used for preoperative design. Surgical templates are fabricated by a MEX 3D printer (Lingtong III, Beijing SHINO, Beijing, China). Postoperative CBCT data are obtained after surgical template placement. The differences in positions of X, Y, Z, and dXYZ as well as angulations between the placed and the designed template are measured on labiolingual and mesiodistal planes. The deviations of the planned and the actual outcome in each dimension are observed and analyzed. Data from different samples indicate that the mean deviation of the angle measures approximately 3.640°. For position deviation, the maximum deviation is found in the z-direction and the mean deviation is about 0.365 ± 0.136 mm. The mean deviation of space Euclidean distance dXYZ is approximately 0.537 ± 0.123 mm. Implant templates fabricated by MEX present a relatively high accuracy for tooth-supported guide implantation.

Digital vs. conventional workflow for one-abutment one-time immediate restoration in the esthetic zone: a randomized controlled trial

OBJECTIVES

To compare short-term outcomes after immediate restoration of a single implant in the esthetic zone with one-abutment one-time technique comparing a conventional (control) vs. a fully digital workflow (test).

MATERIALS AND METHODS

Eighteen subjects were randomly assigned to the two groups, and a digital implant planning was performed for all. In the test group, a custom-made zirconia abutment and a CAD-CAM provisional crown were prepared prior to surgery; implants were placed using a s-CAIS guide allowing immediate restoration after surgery. In the control group, the implant was placed free-handed using a conventional surgical guide, and a custom-made zirconia abutment to support a stratified provisional crown was placed 10 days thereafter, based on a conventional impression. Implant accuracy (relative to the planning), the provisional restoration outcomes, as well as PROMs were assessed.

RESULTS

The implant positioning showed higher accuracy with the s-CAIS surgical guide compared to free-handed surgery (angular deviation (AD): 2.41 ± 1.27° vs. 6.26 ± 3.98°, p < 0.014; entry point deviation (CGD): 0.65 ± 0.37 mm vs. 1.27 ± 0.83 mm, p < 0.059; apical deviation (GAD): 1.36 ± 0.53 mm vs. 2.42 ± 1.02 mm, p < 0.014). The occlusion and interproximal contacts showed similar results for the two workflows (p = 0.7 and p = 0.69, respectively). The PROMs results were similar in both groups except for impression taking with intra-oral scanning preferred over conventional impressions (p = 0.014).

CONCLUSIONS

Both workflows allowed implant placement and immediate/early restoration and displayed similar clinical and esthetic outcomes. The fully digital workflow was associated with a more accurate implant position relative to planning.

CLINICAL RELEVANCE

Our results show that both conventional and digital workflow are predictive and provide similar clinical outcomes, with extra precision provided by digitalisation.

Immediate loading protocols increase the risk of failure of implants placed by fully guided surgery in partially edentulous jaws: A randomized clinical trial

AIM

To compare the 1-year outcomes of immediate loading (IL) and delayed loading (DL) protocols for implants placed by fully guided surgery in partially edentulous jaws.

MATERIALS AND METHODS

This study included 72 patients who received implant surgery with either IL (93 implants, 36 patients) or DL (94 implants, 26 patients). A prefabricated provisional prosthesis was delivered immediately for the IL group (86 implants, 32 patients) with the exception of 4 subjects in whom an initial torque of >20 Ncm and an implant stability quotient of >65 were not achieved, while all DL-group implants were loaded after 3 months. The 1-year implant survival rate estimated by intention-to-treat (ITT) and per-protocol (PP) analyses, and the marginal bone loss (MBL) estimated by cone-beam computed tomography were statistically evaluated (p < 0.05).

RESULTS

The survival rate in the DL group was 100% at both patient and implant levels. With only 26 subjects with 78 implants surviving in the IL group, the survival rates were 69.4% and 83.4% at the patient and implant levels, respectively, in the ITT analysis, and 78.1% and 90.2% in the PP analysis. All intergroup differences in survival rates were statistically significant (p < 0.01). MBL was less than 0.1 mm in both groups (p > 0.05).

CONCLUSIONS

IL for implants placed by fully guided surgery in the partially edentulous jaws increased the probability of failure compared to 3-month DL. Regardless of when loading occurred, marginal bone levels remained stable.

Immediate Loading of Implants Placed by Guided Surgery in Geriatric Edentulous Mandible Patients

The aim of this study was to show the clinical outcomes of the immediate loading of implants inserted by guided surgery in edentulous mandible patients. Edentulous mandible patients were diagnosed with oral examination, cone beam computerized tomography and diagnostic casts for intermaxillary relations and treated with 8–10 implants for rehabilitation with guided surgery and immediate loading. After flapless surgery, implants were loaded with an immediate acrylic temporary prosthesis. After a period of six months, a ceramic definitive full-arch prosthesis was placed. A total of 22 patients (12 females and 10 males) were treated with 198 implants. Eleven patients (50%) had a previous history of periodontitis. Six patients (27.3%) were smokers. The follow-up was 84.2 ± 4.9 months. Clinical outcomes showed a global success rate of 97.5% of implants. Five implants were lost during the healing phase with provisional prosthesis. Twenty-two fixed full-arch rehabilitations were placed in the patients over the 193 remaining implants. Mean marginal bone loss was 1.44 mm ± 0.45 mm. Six patients (27.3%) showed some kind of mechanical prosthodontic complication. Eighteen (9.3%) of the 193 remaining implants were associated with peri-implantitis. The antecedents of peri-implantitis are critical elements for the survival of the implants. The loss of implants was significant in patients who smoked up to 10 cigarettes, compared to non-smokers. Peri-implantitis is one of the key elements in the long-term follow-up of implants and it was more manifest in smoking patients, and in those with a history of peri-implantitis. Marginal bone loss was more significant in smokers. Full-arch rehabilitation is presented as a predictable alternative with minor fatigue problems that are easily solvable.

Five-year survival rates for implants placed using digitally-designed static surgical guides: a systematic review

Digitally-designed static surgical guides provide an acceptable level of accuracy and predictability for the placement of dental implants. However, to our knowledge, few published studies have compared the long-term survival of implants placed in this way with those placed using other methods. A systematic search of electronic databases using a population, intervention, comparison, and outcome (PICO) framework was conducted of Medline and EMBASE, as well as grey literature and hand searches, to obtain all relevant work pertaining to the survival of dental implants placed by guided surgery. The studies were required to have at least 10 patients with a follow up of at least five years. A total of 621 titles were screened. Four studies met the inclusion criteria for quantitative analysis, and they all reported the exclusive use of Nobel Biocare implants and the NobelGuide system (Nobel Biocare Services). Cumulative survival rates ranged from 94.5% to 100% over five years. The survival rates of implants placed using digitally-designed static surgical guides are comparable to the estimated overall survival rate (95.6% over five years), despite the complex nature of the treatments done with guided surgery. Clinicians who do these operations should, however, have the experience and ability to revert to conventional freehand techniques if complications arise.

The influence of prosthetic material on implant and prosthetic survival of implant-supported fixed complete dentures: a systematic review and meta-analysis

PURPOSE

Evaluating the impact of the prosthetic material on implant- and prosthetic survival of implant-supported fixed complete dentures.

STUDY SELECTION

Electronic and hand searches were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to identify clinical studies including at least 10 patients restored with implant-supported dentures. The primary outcome was to evaluate the implant survival rate according to the applied restorative materials. The prosthetic survival rate was evaluated as secondary outcomes.

RESULTS

Forty-one of 2254 studies were finally selected. A statistically significant difference (p = 0.0337) was found between implant survival rates in the main restorative groups (metal-ceramic:97%(95%CI [0.96;0.98]), all-ceramic:99%(95%CI [0.98;1.00]), metal-resin:97%(95%CI [0.96;0.98])). Prosthetic survival rates were: (metal-ceramic:95%(95%CI [0.89;0.97]), all-ceramic:97%(95%CI [0.92;0.99]), metal-resin:97%(95%CI [0.95;0.98]), with no statistically significant difference (p = 0.3796) between the groups. Chipping incidence rates were as follows: metal-ceramic:8%(95%CI[0.03;0.20]), all-ceramic:15%(95%CI [0.06;0.32]), and metal-resin:22%(95%CI [0.13;0.33]). Five types of exact restorative materials were identified (porcelain-fused-to-non-precious alloy, porcelain-fused-to-zirconia, precious-metal-acrylic-resin, non-precious-metal-acrylic resin, and PMMA). Again, implant survival rates were statistically significantly influenced by the applied restorative materials (p = 0.0126), whereas, no significant differences were reported regarding prosthetic survival rate.

CONCLUSIONS

Prosthetic material selection seems to have no clinically relevant influence on implant- and prosthetic survival rate in implant-supported fixed complete dentures. Due to the high chipping rate, quantifying prosthetic survival alone does not seem to be a reliable tool for evaluating the outcome of the restorations and providing recommendations. These results, along with the obvious lack of evidence, suggest that clinicians must exercise caution whenever porcelain-fused-to-zirconia or metal-resin restorations are considered.

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.

Flapless dental implant surgery and use of cone beam computer tomography guided surgery

Flapless implant surgery is increasing in popularity, particularly due to advances and increased usage of cone beam computed tomography (CBCT) and dental implant treatment planning software allowing three-dimensional assessment of the implant site. It is the aim of the article to provide an overview of flapless implant surgery and CBCT guided flapless implant surgery and summarise the literature with regard to the effectiveness of this surgical technique.

Clinical applications and effectiveness of guided implant surgery: a critical review based on randomized controlled trials

Background

Nowadays implant placement protocols are widespread among clinicians all over the world. However, available literature, only partially analyses what can be potential benefits for the clinicians and patients, often focusing just on specific aspects, such as accuracy. The purpose of this review is to compare computer guided implant placement with conventional treatment protocols.

Methods

A search strategy according to the P-I-C-O format was developed and executed using an electronic MEDLINE plus manual search from 2000 up to December 2016. This review included only randomized controlled trials (RCTs) focusing on subjects treated with digital workflow for oral implant placement compared to conventional procedures. Data were extracted from eligible papers and analysed. All kinds of outcomes were considered, even patient-related and economical outcomes.

Results

The search strategy revealed 16 articles; additional manual searches selected further 21 publications. Afterwards the evaluation of articles, only two studies could be selected for subsequent data extraction. The two identified RCTs analysed primary outcomes as prosthesis failure, implant failure, biological or prosthetic complications, and secondary outcomes as periimplant marginal bone loss. One RCT evaluated also the duration of treatment, post-surgical progress, additional treatment costs and patient satisfaction. The other RCT focused instead on evaluating eventual improvement of patient’s quality of life. In both selected studies, were not observed by the authors statistically significant differences between clinical cases treated with digital protocols and those treated with conventional ones. In one RCT, however post-surgical progress evaluation showed more patients’ self-reported pain and swelling in conventional group.

Conclusions

Within the limitation of this review, based on only two RCTs, the only evidence was that implant survival rate and effectiveness are similar for conventional and digital implant placement procedures. This is also confirmed by many other studies with however minor scientific evidence levels. Reduction of post-operative pain, surgical time and overall costs are discussed. Authors believe that scientific research should focus more in identifying which clinical situations can get greatest benefits from implant guided surgery. This should be done with research protocols such as RCT that assess comprehensively the advantages and disadvantages of fully digital surgical protocols.

Definitive Presurgical CAD/CAM-Guided Implant-Supported Crown in an Esthetic Area

This paper describes the digital workflow from cone beam computer tomography (CBCT) to the installation of a definitive presurgical zirconium individual crown in a 19-year-old woman requiring implant replacement of a maxillary right lateral incisor. The patient had agenesis of this tooth and had completed the orthodontic treatment. CBCT was conducted and diagnostic casts were digitized. Virtual planning was completed by defining a prosthetically driven implant and a stereolithographic surgical template was produced. Good adaptation of a stereolithographic surgical template was verified in the working cast. Implant and abutment were installed in this cast using a stereolithographic surgical template, and a CAD/CAM definitive zirconium crown was produced. Flapless computer-guided implant surgery was performed. The abutment was connected, and a definitive zirconium crown was cemented using resin cement. The digital workflow presented herein shows high accuracy for a virtually planned implant with flapless guided placement, allowing the successful delivery of a definitive presurgical zirconium single crown in an esthetic area in a single visit. The patient was revaluated after 1 year of function with an excellent outcome of the treatment.

3D printing in dentistry

3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery.

[Accuracy of computer-guided implant placement and influencing factors]

Digital technology is a new trend in implant dentistry and oral medical technology. Stereolithographic surgical guides, which are computer-guided implant placement, have been introduced gradually to the market. Surgeons are attracted to this approach because of it features visualized preoperative planning, simple surgical procedure, flapless implant, and immediate restoration. However, surgeons are concerned about the accuracy and complications of this approach. This review aims to introduce the classification of computer-guided implant placement. The advantages, disadvantages, and accuracy of this approach are also analyzed. Moreover, factors that may affect the outcomes of computer-guided implant placement are determined. Results will provide a reference to surgeons regarding the clinical application of this approach.

Flap Designs for Implant-Related Surgical Procedures: A Review

PURPOSE

The objective of this study was to compare the reliability and results of 2 flap techniques, flapless (FL) and full-thickness (FT) flap, during implant placement.

MATERIALS AND METHODS

Online and hand searches of the literature published were conducted to identify studies examining different flap techniques on clinical and histological outcomes. The search terms used, alone or in combination, were "flapless," "full-thickness flap," "crestal bone resorption," "gingival blood circulation," and "biological width."

RESULTS

Fifty studies were selected for comparison and to address the points highlighted in this study. Fourteen articles and 1 book were not directly related to flap design but were included for understanding the process of soft tissue healing. Five articles discussed the principles of oral surgery and flap design.

CONCLUSION

This review revealed that the FL technique might be more appropriate in immediate implant loading cases. This specific technique results in shallower biological width, reduced inflammation, less morbidity with guided implant placement, and better esthetics in comparison with the FT technique. The implant survival rates are not significantly different between the 2 flap techniques. With respect to crestal bone resorption in FL and FT, it is inconclusive, depending on the study type (human or animal).

Percutaneous implant retention of a nasal prosthesis

This report describes an approach to the simultaneous retention of a nasal prosthesis and an intraoral prosthesis for a patient who had undergone a total rhinectomy with resection of the upper lip and premaxilla. At the time of the nasal resection, 2 dental implants were placed adjacent to the resection margins in the first premolar positions. These were used to anchor an intraoral, milled titanium bar and overdenture to replace the missing anterior teeth and provide support for the upper lip, which had been reconstructed with a vascularized radial forearm free-flap. The titanium bar also incorporated a connection for a tissue-penetrating percutaneous nasal extension, which pierced the radial forearm flap near the junction with the hard palate. Magnetic attachments screwed to the nasal extension retained a nasal prosthesis. The predictable and straightforward implementation of this novel concept with digital design and manufacture of the titanium components and guided placement of the nasal extension was made possible with software planning.

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

PURPOSE

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.

METHODS

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.

RESULTS

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 1 year 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.

CONCLUSIONS

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.

Combining guided alveolar ridge reduction and guided implant placement for all-on-4 surgery: A clinical report

Immediate restoration with the all-on-4 concept has become an established treatment option. The technique involves alveoloplasty before implant placement to provide space for the prosthetic components and to provide a platform on which dental implants can be placed in clinical situations where a knife-edge alveolar ridge is present. Guided implant surgery involves the fabrication of a guide by using data from cone-beam computed tomography (CBCT) and implant surgery performed without flap reflection. In the presented technique, a printed cast based on a CBCT is used to fabricate a guide for both alveolar ridge reduction and guided implant surgery. The alveolar ridge reduction and implant surgery are virtually simulated in the laboratory to provide space for the restorative components and to avoid critical anatomic landmarks (mental nerve or perforation of the lingual mandibular plate). The described surgical guide enables guided alveolar ridge reduction and guided implant placement where the implant placement performed in the laboratory can be duplicated clinically during implant surgery.

In vitro evaluation of the marginal integrity of CAD/CAM interim crowns

STATEMENT OF PROBLEM

The accuracy of interim crowns made with computer-aided design and computer-aided manufacturing (CAD/CAM) systems has not been well investigated.

PURPOSE

The purpose of this in vitro study was to evaluate the marginal integrity of interim crowns made by CAD/CAM compared with that of conventional polymethylmethacrylate (PMMA) crowns.

MATERIAL AND METHODS

A dentoform mandibular left second premolar was prepared for a ceramic crown and scanned for the fabrication of 60 stereolithical resin dies, half of which were scanned to fabricate 15 Telio CAD-CEREC and 15 Paradigm MZ100-E4D-E4D crowns. Fifteen Caulk and 15 Jet interim crowns were made on the remaining resin dies. All crowns were cemented with Tempgrip under a 17.8-N load, thermocycled for 1000 cycles, placed in 0.5% acid fuschin for 24 hours, and embedded in epoxy resin before sectioning from the mid-buccal to mid-lingual surface. The marginal discrepancy was measured using a traveling microscope, and dye penetration was measured as a percentage of the overall length under the crown.

RESULTS

The mean vertical marginal discrepancy of the conventionally made interim crowns was greater than for the CAD/CAM crowns (P=.006), while no difference was found for the horizontal component (P=.276). The mean vertical marginal discrepancy at the facial surface of the Caulk crowns was significantly greater than that of the other 3 types of interim crowns (P<.001). At the facial margin, the mean horizontal component of the Telio crowns was significantly larger than that of the other 3 types, with no difference at the lingual margins (P=.150). The mean percentage dye penetration for the Paradigm MZ100-E4D crowns was significantly greater and for Jet crowns significantly smaller than for the other 3 crowns (P<.001). However, the mean percentage dye penetration was significantly correlated with the vertical and horizontal marginal discrepancies of the Jet interim crowns at the facial surface and with the horizontal marginal discrepancies of the Caulk interim crowns at the lingual surface (P<.01 in each instance).

CONCLUSIONS

A significantly smaller vertical marginal discrepancy was found with the interim crowns fabricated by CAD/CAM as compared with PMMA crowns; however, this difference was not observed for the horizontal component. The percentage dye penetration was correlated with vertical and horizontal discrepancies at the facial surface for the Jet interim crowns and with horizontal discrepancies at the lingual surface for the Caulk interim crowns.

Computer-assisted surgery and intraoral welding technique for immediate implant-supported rehabilitation of the edentulous maxilla: case report and technical description

BACKGROUND

Complications are frequently reported when combining computer assisted flapless surgery with an immediate loaded prefabricated prosthesis. The authors have combined computer-assisted surgery with the intraoral welding technique to obtain a precise passive fit of the immediate loading prosthesis.

METHODS

An edentulous maxilla was rehabilitated with four computer assisted implants welded together intraorally and immediately loaded with a provisional restoration.

RESULTS

A perfect passive fit of the metal framework was obtained that enabled proper osseointegration of implants. Computer assisted preoperative planning has been shown to be effective in reducing the intraoperative time of the intraoral welding technique. No complications were observed at 1 year follow-up.

CONCLUSIONS

This guided-welded approach is useful to achieve a passive fit of the provisional prosthesis on the inserted implants the same day as the surgery, reducing intraoperative time with respect to the traditional intraoral welding technique. Copyright © 2015 John Wiley & Sons, Ltd.

Immediate loading of two freestanding implants placed by computer-guided flapless surgery supporting a mandibular overdenture with magnetic attachments

PURPOSE

The present article describes a novel clinical procedure for mandibular overdentures supported by two freestanding implants loaded immediately after placement via computer-guided flapless surgery.

METHODS

A conventional acrylic complete denture was fabricated, and CT scans obtained using the denture as a radiographic guide. Preoperative computer-assisted planning was performed using commercially available software, permitting simulation of implant placement at optimal positions. Using simulation data, a surgical guide was manufactured and used during surgery. The surgical guide was placed and local anesthesia injected for drilling of anchor pins to stabilize the surgical guide. The drilling protocol for each osteotomy site achieved an insertion torque greater than 35 Ncm. Immediately after implant placement, a keeper of the magnetic attachment was connected to each implant, and the magnetic assembly incorporated into the denture. The mucosal surface of the denture around the magnet was relieved to avoid excessive tissue pressure. The patients were instructed to wear the denture in place continually for the following 7 days. After six months of healing and follow-up, a final denture with a metal framework may be fabricated if necessary.

CONCLUSION

A novel treatment protocol for immediately loaded implant-supported mandibular overdentures is described in detail. The protocol ensures secure precise and safe implant placement, successful osseointegration, and immediate improvement of oral health-related quality of life for patients with unstable complete dentures.

Implant-supported overdenture manufactured using CAD/CAM techniques to achieve horizontal path insertion between the primary and secondary structure: A clinical case report

This report describes the case of an edentulous patient with an atrophic maxilla and severe class III malocclusion. Prosthetic rehabilitation was performed using CAD/CAM techniques for manufacturing an implant-supported overdenture with horizontal insertion. A vestibulo-lingual insertion overdenture is a precision prosthesis with a fixation system affording a good fit between the primary and secondary structure. Both structures exhibit passive horizontal adjustment. This treatment option requires the same number of implants as implant-supported fixed dentures. The horizontal assembly system prevents the prosthesis from loosening or moving in response to axial and non-axial forces. The technique was used to rehabilitate a patient presenting an atrophic upper maxilla, with the insertion of 8 implants. No complications were reported at follow-up 3, 6 and 12 months after fitting of the prosthesis. This system offers solutions to the clinical and laboratory complications associated with hybrid prostheses, concealing emergence of the chimneys and improving implant-prosthesis hygiene.

Computer-Guided Implant Surgery in Fresh Extraction Sockets and Immediate Loading of a Full Arch Restoration: A 2-Year Follow-Up Study of 14 Consecutively Treated Patients

Statement of Problem. Low scientific evidence is identified in the literature for combining implant placement in fresh extraction sockets with immediate function. Moreover, the few studies available on immediate implants in postextraction sites supporting immediate full-arch rehabilitation clearly lack comprehensive protocols. Purpose. The purpose of this study is to report outcomes of a comprehensive protocol using CAD-CAM technology for surgical planning and fabrication of a surgical template and to demonstrate that immediate function can be easily performed with immediate implants in postextraction sites supporting full-arch rehabilitation. Material and Methods. 14 subjects were consecutively rehabilitated (13 maxillae and 1 mandible) with 99 implants supporting full-arch fixed prostheses followed between 6 and 24 months (mean of 16 months). Outcome measures were prosthesis and implant success, biologic and prosthetic complications, pain, oedema evaluation, and radiographic marginal bone levels at surgery and then at 6, 12, 18, and 24 months. Data were analyzed with descriptive statistics. Results. The overall cumulative implant survival rate at mean follow-up time of 16 months was 97.97%. The average marginal bone loss was 0,9 mm. Conclusions. Within the limitations of this study, the results validate this treatment modality for full-arch rehabilitations with predictable outcomes and high survival rate after 2 years.

Smoking and dental implants: A systematic review and meta-analysis

OBJECTIVE

Recent studies implicate smoking as a significant factor in the failure of dental implants. This review aims to test the null hypothesis of no difference in the implant failure rates, risk of postoperative infection, and marginal bone loss for smokers versus non-smokers, against the alternative hypothesis of a difference.

DATA

Main search terms used in combination: dental implant, oral implant, smoking, tobacco, nicotine, smoker, and non-smoker.

SOURCES

An electronic search was undertaken in September/2014 in PubMed/Medline, Web of Science, Cochrane Oral Health Group Trials Register plus hand-searching.

STUDY SELECTION

Eligibility criteria included clinical human studies, either randomized or not. The search strategy resulted in 1432 publications, of which 107 were eligible, with 19,836 implants placed in smokers, with 1259 failures (6.35%), and 60,464 implants placed in non-smokers, with 1923 failures (3.18%).

CONCLUSIONS

The insertion of implants in smokers significantly affected the failure rates, the risk of postoperative infections as well as the marginal bone loss. The results should be interpreted with caution due to the presence of uncontrolled confounding factors in the included studies.

CLINICAL SIGNIFICANCE

Smoking is a factor that has the potential to negatively affect healing and the outcome of implant treatment. It is important to perform an updated periodic review to synthesize the clinical research evidence relevant to the matter.

Accuracy and reliability of stitched cone-beam computed tomography images

PURPOSE

This study was performed to evaluate the linear distance accuracy and reliability of stitched small field of view (FOV) cone-beam computed tomography (CBCT) reconstructed images for the fabrication of implant surgical guides.

MATERIALS AND METHODS

Three gutta percha points were fixed on the inferior border of a cadaveric mandible to serve as control reference points. Ten additional gutta percha points, representing fiduciary markers, were scattered on the buccal and lingual cortices at the level of the proposed complete denture flange. A digital caliper was used to measure the distance between the reference points and fiduciary markers, which represented the anatomic linear dimension. The mandible was scanned using small FOV CBCT, and the images were then reconstructed and stitched using the manufacturer's imaging software. The same measurements were then taken with the CBCT software.

RESULTS

The anatomic linear dimension measurements and stitched small FOV CBCT measurements were statistically evaluated for linear accuracy. The mean difference between the anatomic linear dimension measurements and the stitched small FOV CBCT measurements was found to be 0.34 mm with a 95% confidence interval of +0.24 - +0.44 mm and a mean standard deviation of 0.30 mm. The difference between the control and the stitched small FOV CBCT measurements was insignificant within the parameters defined by this study.

CONCLUSION

The proven accuracy of stitched small FOV CBCT data sets may allow image-guided fabrication of implant surgical stents from such data sets.

The NobelGuide® All-on-4® Treatment Concept for Rehabilitation of Edentulous Jaws: A Prospective Report on Medium- and Long-Term Outcomes

BACKGROUND

There is a need for long-term studies on complete edentulous flapless rehabilitations.

PURPOSE

This study aimed to evaluate the long-term outcomes of the rehabilitation of completely edentulous jaws for immediate function with the All-on-4® treatment concept using a computer-guided surgical protocol (NobelGuide®, Nobel Biocare, Göteborg, Sweden).

MATERIALS AND METHODS

This prospective clinical study included 23 totally edentulous patients rehabilitated between February 2005 and May 2006 with 92 implants with the All-on-4 treatment concept using NobelGuide. Outcome measures were implant survival, marginal bone loss at 1, 3, and 5 years, and the incidence of mechanical and biological complications. Survival was calculated using life-table analysis.

RESULTS

Two dropouts occurred. The cumulative implant survival rate was 96.6% at 5 years of follow-up. Prosthetic survival was 100%. The average marginal bone loss was 1.7 mm (standard deviation 1.4 mm) at 1 year, 1.7 mm (standard deviation 0.9 mm) at 3 years, and 1.9 mm (standard deviation 1.1 mm) at 5 years. Seven patients experienced fracture of the definitive prosthesis (6 patients were heavy bruxers), and abutment screw loosening occurred in 2 patients. Two implants in 2 patients showed peri-implant pathology.

CONCLUSIONS

Within the limitations of this study, it is possible to conclude that this treatment modality for completely edentulous jaws is safe and predictable with good long-term outcomes.

A subtractive radiographic template for computer-guided surgery

The procedure for creating a computer-aided design/computer-aided manufactured surgical template with the NobelClinician software was originally designed for the completely edentulous arch. With the development of new techniques and expanded functions in the software, guided surgery for the partially edentulous became a viable option. As of yet, few protocols have been reported for the guided surgery of immediate implants with the NobelClinician software. A new technique is described whereby the radiographic template is modified to allow the use of guided surgery for the immediate placement of dental implants after extractions.

Computer-designed selective laser sintering surgical guide and immediate loading dental implants with definitive prosthesis in edentulous patient: A preliminary method

Objective:

The aim of this study was to analyze a preliminary method of immediately loading dental implants and a definitive prosthesis based on the computer-aided design/computer-aided manufacturing systems, after 2 years of clinical follow-up.

Materials and Methods:

The study comprised one patient in good general health with edentulous maxilla. Cone beam computer tomography (CBCT) was performed using a radiographic template. The surgical plan was made using the digital imaging and communications in medicine protocol with ImplantViewer (version 1.9, Anne Solutions, Sao Paulo, SP, Brazil), the surgical planning software. These data were used to produce a selective laser sintering surgical template. A maxilla prototype was used to guide the prosthesis technician in producing the prosthesis. Eight dental implants and a definitive prosthesis were installed on the same day. A post-operative CBCT image was fused with the image of the surgical planning to calculate the deviation between the planned and the placed implants positions. Patient was followed for 2 years.

Results:

On average, the match between the planned and placed angular deviation was within 6.0 ± 3.4° and the difference in coronal deviation was 0.7 ± 0.3 mm. At the end of the follow-up, neither the implant nor the prosthesis was lost.

Conclusions:

Considering the limited samples number, it was possible to install the dental implants and a definitive prosthesis on the same day with success.

Stabilization of a computer-aided implant surgical guide using existing dental implants with conversion of an overdenture to a fixed prosthesis

This clinical report describes a technique to stabilize a computer-aided dental implant surgical guide to existing implants. A patient requested conversion of her existing mandibular implant-assisted overdenture into a fixed complete denture. The surgical procedure was planned virtually, and the two existing dental implants were integrated into the surgical plan as a means to fixate the surgical guide. The implants were placed, and the patient's prosthesis was converted into an interim fixed complete denture.

Clinical advantages of computer-guided implant placement: a systematic review

OBJECTIVES

To systematically scrutinize the current scientific literature regarding the clinical advantages of computer guidance of implant placement.

MATERIALS AND METHODS

Four electronic databases were searched using specified indexing terms. The reference lists of publications were also searched manually. For inclusion, publications had to meet pre-established criteria.

RESULTS

The searches yielded 1028 titles and abstracts. After data extraction and interpretation, 28 publications and 2 systematic reviews remained for inclusion. Fifteen studies were prospective observational and four were retrospective observational. Nine studies included a control group (controlled clinical trials) of which seven were prospective and two retrospective. Only three of the prospective studies were randomized (RCT's). A total of 852 patients were treated with 4032 implants using computer-guided implant surgery. The number of patients included in each study ranged from 6 to 206. The age ranged from 16 to 92 years and the follow-up period varied between 1 and 49 months.

CONCLUSIONS

The limited scientific evidence available suggests that guided placement has at least as good implant survival as conventional protocols. However, several unexpected procedure-linked adverse events during guided implant placement indicate that the clinical demands on the surgeon were no less than those during conventional placement. A clinical advantage with flapless guided surgery is that the technique is likely to decrease pain and discomfort in the immediate postoperative period.

Outcomes of implants placed with three different flapless surgical procedures: a systematic review

The aim of this systematic review was to evaluate the outcomes of flapless surgery for implants placed using either free-hand or guided (with or without 3D navigation) surgical methods. Literature searches were conducted to collect information on survival rate, marginal bone loss, and complications of implants placed with such surgeries. Twenty-three clinical studies with a minimum of 1 year follow-up time were finally selected and reviewed. Free-hand flapless surgery demonstrated survival rates between 98.3% and 100% and mean marginal bone loss between 0.09 and 1.40 mm at 1-4 years after implant insertion. Flapless guided surgery without 3D navigation showed survival rates between 91% and 100% and mean marginal bone loss of 0.89 mm after an observation period of 2-10 years. The survival rates and mean marginal bone loss for implants placed with 3D guided flapless surgery were 89-100% and 0.55-2.6mm, respectively, at 1-5 years after implant insertion. In 17 studies, surgical and technical complications such as bone perforation, fracture of the surgical guide, and fracture of the provisional prosthesis were reported. However, none of the identified methods has demonstrated advantages over the others. Further studies are needed to confirm the predictability and effectiveness of 3D navigation techniques.

The effect of flapless surgery on implant survival and marginal bone level: a systematic review and meta-analysis

BACKGROUND

The clinical outcomes of implants placed using the flapless approach have not yet been systematically investigated. Hence, the present systematic review and meta-analysis aims to study the effect of the flapless technique on implant survival rates (SRs) and marginal bone levels (MBLs) compared with the conventional flap approach.

METHODS

An electronic search of five databases (from 1990 to March 2013), including PubMed, Ovid (MEDLINE), EMBASE, Web of Science, and Cochrane Central, and a hand search of peer-reviewed journals for relevant articles were performed. Human clinical trials with data on comparison of SR and changes in MBL between the flapless and conventional flap procedures, with at least five implants in each study group and a follow-up period of at least 6 months, were included.

RESULTS

Twelve studies, including seven randomized controlled trials (RCTs), one cohort study, one pilot study, and three retrospective case-controlled trials (CCTs), were included. The SR of each study was recorded, weighted mean difference (WMD) and confidence interval (CI) were calculated, and meta-analyses were performed for changes in MBL. The average SR is 97.0% (range, 90% to 100%) for the flapless procedure and 98.6% (range, 91.67% to 100%) for the flap procedure. Meta-analysis for the comparison of SR among selected studies presented a similar outcome (risk ratio = 0.99, 95% CI = 0.97 to 1.01, P = 0.30) for both interventions. Mean differences of MBL were retrieved from five RCTs and two retrospective CCTs and subsequently pooled into meta-analyses; however, none of the comparisons showed statistical significance. For RCTs, the WMD was 0.07, with a 95% CI of -0.05 to 0.20 (P = 0.26). For retrospective CCTs, the WMD was 0.23, with a 95% CI of -0.58 to 1.05 (P = 0.58). For the combined analysis, the WMD was 0.03, with a 95% CI of -0.11 to 0.18 (P = 0.67). The comparison of SR presented a low to moderate heterogeneity, but MBL presented a considerable heterogeneity among studies.

CONCLUSION

This systematic review revealed that the SRs and radiographic marginal bone loss of flapless intervention were comparable with the flap surgery approach.

Computer guided implantology accuracy and complications

The computer-based method allows the computerized planning of a surgical implantology procedure, using computed tomography (CT) of the maxillary bones and prosthesis. This procedure, however, is not error-free, unless the operator has been well trained and strictly follows the protocol. A 70-year-old woman whom was edentulous asked for a lower jaw implant-supported prosthesis. A computer-guided surgery was planned with an immediate loading according to the NobelGuide technique. However, prior to surgery, new dentures were constructed to adjust the vertical dimension. An interim screwed metal-resin prosthesis was delivered just after the surgery; however, after only two weeks, it was removed because of a complication. Finally, a screwed implant bridge was delivered. The computer guided surgery is a useful procedure when based on an accurate 3D CT-based image data and an implant planning software which minimizes errors.