Accuracy of fully guided dental implant placement: A prospective clinical in-vivo investigation using intraoral scan data.

AIM: To compare the planned implant position (PIP) with the transferred implant position (TIP) after fully guided implant placements in single-tooth gaps. MATERIALS AND METHODS: Dental implant placements were planned using two different implant systems (Camlog Screw-Line [C-SL] and Straumann Bone Level Tapered [S-BLT]), and two different planning software programs (SMOP and coDiagnostiX). All implants were placed according to fully guided protocols, and intraoral scans were performed intraoperatively. For the comparison of PIP and TIP, scan data were imported to Geomagic Control X (GCX) software and accuracies were evaluated. Deviations were reported in a coordinate system (x- [mesiodistal], y- [vestibulo-oral], and z- [vertical] axis) at entry points and apices. Total deviations, including angular deviations, were calculated with GCX. For statistical analysis, the level of significance was set to P < 0.05. RESULTS: Twenty-six patients received 26 implants. Mean 3D deviation at the implant's entry point was 0.61 mm ± 0.28 for C-SL and 0.63 mm ± 0.24 for S-BLT. For the implant's apex, mean 3D deviation of 0.96 mm ± 0.41 was documented for C-SL and 1.04 mm ± 0.34 for S-BLT. Mean angular deviation was 2.58 degrees ± 1.40 for C-SL and 2.89 degrees ± 1.12 for S-BLT. Statistical analysis revealed no significant differences between implant systems, but showed significant deviations regarding the z-axis, both at entry point and apex (P < 0.05). CONCLUSIONS: Fully guided implant placements in single-tooth gaps provide accurate results. Due to significant vertical deviations, reevaluation of both drilling and insertion depths prior to implant installation should be considered. Maintenance of 1.5- to 2-mm safety distances to critical structures was confirmed.

Immediate loading of a fixed full-arch prosthesis on four template-guided implants.

BACKGROUND: Treatment of the edentulous maxilla with a fixed full-arch prosthesis on four immediately loaded implants has been discussed as a treatment option, although generally five implants are recommended for that indication. The precise transfer of the virtually planned position by 3D-guided implant placement is an essential prerequisite for delivering the prefabricated temporary restoration at the time of surgery. Three-point support on the teeth or implants ensures that the template for the guided surgery is soundly seated during the operation. CASE PRESENTATION: In the described case, the three-point support was carried out by teeth and temporary implants in the molar region inserted prior to the CBCT. The virtual implant planning determined the best prosthetic implant position while using the available bone to avoid extensive augmentation. Following this, a metal-reinforced provisional restoration was prepared using a drilling template. Four implants were placed in the planned position with the aid of a tooth-/implant-supported guide. The prosthetic axis of the angulated distal implants is balanced by 17-degree angled abutments. After transferring the implant position to the dental laboratory, the prepared restoration was finalized. The remaining teeth were extracted and the temporary restoration was delivered 3 h after implant placement. The definitive fixed full-arch zirconia restoration with micro layering was placed 9 months later in a stable situation. CONCLUSION: The remarkable accuracy of the implant placement with a surgical template generated from preoperative virtual implant planning ensures a relatively short treatment time and an uneventful and fast recovery with minimal discomfort. The immediate prosthodontic rehabilitation is a benefit, not only for the patient but also for the dental team. Micro-layered monolithic zirconia seems to be a promising option for screw-retained full-arch prostheses.

Possibilities and limitations of computer-assisted implant planning and guided surgery in the anterior region.

Three-dimensional (3D) implant positioning is an important prognostic factor for anterior dental implants. Modern 3D imaging and implant treatment planning systems are available today for precise dental implant planning and placement. The transfer of implant position information to industrially manufactured templates for guided implant surgery has been possible for years now. What is new is the possibility of combining the datasets with the surface scan data of a diagnostic wax-up and setup for prosthetic-driven implant planning. Digital setups can also be used. This article describes and discusses the available options for digital implant planning and guided surgery.

Navigation in implantology.

The primary objective of implant insertion is optimal prosthetic implant positioning while simultaneously protecting sensitive anatomical structures. In this context, navigated implants show significantly better results than freehand-inserted implants. Computer-assisted navigation, in combination with three-dimensional (3D) imaging by cone beam computed tomography (CBCT), is an ideal way to achieve higher predictability for successful implant therapy. Basically, one can distinguish between static navigation using templates, and direct dynamic navigation using optical transmission systems. Both options demonstrate comparably good results as far as the precision of implant positioning is concerned. Today, the gold standard is digital manufacturing of the template. Direct navigation is the more attractive option, provided acquisition costs can be reduced by simplifying the system. This article presents patient cases that demonstrate different variants of navigated implantology.

Forced Orthodontic Extrusion to Restore the Unrestorable: A Proof of Concept.

The purpose of this clinical study was to assess the feasibility of forced orthodontic extrusion with the Tissue Master Concept to retain subgingivally fractured teeth as abutments for which extraction and replacement would be equal treatment opportunities. Participants were recruited from a group of consecutive patients in need of prosthodontic rehabilitation. In total, 36 deeply destroyed teeth in 31 patients underwent forced orthodontic extrusion with forces exceeding 50 g to reestablish biologic width and ensure a 2-mm dentin-ferrule design prior to single-crown restoration. The primary endpoint was the success of the extrusion in terms of the ability to restore the respective abutment tooth. Information about overall treatment time, frequency, and reasons for failure were collected. Four patients dropped out of the treatment. For the remaining 27 participants, data were fully collected. The amount of extrusion ranged between 2 and 6 mm (3.5 ± 0.9 mm), and the mean duration until retention was 20 ± 12 days. On average, patients returned three (± 3) times for control visits after extrusion. Adhesive failure (n = 6) and orthodontic relapse (n = 2) were the most frequent complication types. Forced orthodontic extrusion may be a useful tool to restore teeth evaluated as nonrestorable.

Dynamic navigation for dental implant placement in single-tooth gaps: A preclinical pilot investigation.

OBJECTIVES: To compare the planned (PIP) and transferred implant position (TIP) after dental implant placement in single-tooth gaps utilizing dynamic computer-assisted implant surgery (dCAIS). METHODS: Five pairs of artificial jaws (n = 5) with four single tooth gaps in FDI (Fédération Dentaire Internationale) regions 16, 25, 36 and 44 were manufactured via injection molding technique. Cone beam computed tomographies (CBCTs) were made and digital implant planning of twenty implants (n = 20) was performed with a dynamic navigation system (DNS, Navident, ClaroNav, Toronto, Canada). After guided drilling and manual implant placement, post-operative CBCTs were made. Global deviations at entry point (two-dimensional, 2D), apex (three-dimensional, 3D), apex (vertical, V) and angulation (in degrees, °) were calculated by DNS software. For statistical analysis, level of significance was set to p < 0.05. RESULTS: Mean deviation at the implants entry point (2D) was 0.78 ± 0.45 mm (range: 0.10-1.63 mm). For the implants apex (3D) and the implants apex (V) deviations were 1.08 ± 0.50 mm (range: 0.33-2.10 mm) and 0.32 ± 0.22 mm (range: 0.02-0.90 mm), respectively. The median angular deviation (°) was 2.81 ± 2.29° (range: 0.56-9.58°). Statistically significant differences (p < 0.05) were found regarding apex (3D), apex (V), and angulation (°) comparing I.-IV. quadrants. CONCLUSIONS: Using the investigated dCAIS seems to provide satisfactory results regarding TIP in single-tooth gaps in vitro. Due to documented deviations, a safety distance of more than 2 mm should be respected while implant planning in DNS software. CLINICAL SIGNIFICANCE: The investigated DNS seems to be reliant in transferring PIP with acceptable deviations in vitro.

Implant or Tooth?-A Prospective Clinical Study on Oral Health-Related Quality of Life for Patients with "Unrestorable" Teeth.

In cases of severely compromised teeth, dental practitioners are confronted with the therapeutic decision of whether to restore a tooth or replace it with an implant. Comparative scientific evidence on patient perception of both treatment approaches is scarce. The subject of this prospective clinical study was to compare oral health-related quality of life (OHRQoL) between two treatment groups: restoration of severely destroyed teeth after orthodontic extrusion (FOE) versus tooth extraction and implant-supported single crown restoration (ISC). A self-selected trial was performed with 21 patients per group. OHRQoL was assessed with the aid of the Oral Health Impact Profile (OHIP-G49) at different time intervals: before treatment (T1), after treatment (T2), after restoration (T3) and at recall (T4). Overall, OHIP scores improved from baseline to follow-up for both concepts with no significant differences between groups. There were no significant differences in subscales between FOE and ISC at T1, T3 and T4. In terms of functional limitations (p = 0.003) and physical disability (p = 0.021), patients in the FOE group temporarily exhibited lower OHRQoL at T2 in comparison to the ISC group. However, at baseline, after final restoration and at recall, the study demonstrates the same level of OHRQoL for both treatment concepts.

Recommendations for Implant-Supported Full-Arch Rehabilitations in Edentulous Patients: The Oral Reconstruction Foundation Consensus Report.

The tasks of Working Groups 1 to 6 at the 4th Consensus Meeting of the Oral Reconstruction Foundation were to elucidate clinical recommendations for implant-supported full-arch rehabilitations in edentulous patients. Six systematic/narrative reviews were prepared to address the following subtopics: (1) the influence of medical and geriatric factors on implant survival; (2) the prevalence of peri-implant diseases; (3) the influence of material selection, attachment type, interarch space, and opposing dentition; (4) different interventions for rehabilitation of the edentulous maxilla; (5) different interventions for rehabilitation of the edentulous mandible; and (6) treatment choice and decision-making in elderly patients. Consensus statements, clinical recommendations, and implications for future research were determined based on structured group discussions and plenary session approval.

Reliability of an injection-moulded two-piece zirconia implant with PEKK abutment after long-term thermo-mechanical loading.

Zirconia implants are appreciated in some clinical indications in light of their aesthetic appearance and good biocompatibility. The aim of this work was to evaluate the performance of a newly developed two-piece zirconia/polyether ketone ketone (PEKK) implant-abutment combination after long-term cyclic loading in a hydrothermal environment, using a new protocol adapted from two available ISO standards. Sixteen implants (n = 8/group) were embedded according to ISO 14801 and divided into two groups: implants in the Observational Group (OG) were cyclically loaded for 60 days (98 N, 10 million loading cycles, 2 Hz) in 85 °C water in a chewing simulator, while non-loaded/non-aged implants (as-received) constituted the Control Group (CG). After 4.7 million loading cycles, one OG implant fractured in the chewing simulator. The surviving implants were compared to CG implants by X-ray diffraction (XRD) to investigate potential ageing as suggested by ISO 13356, but also µ-Raman spectroscopy, Focused-Ion-Beam - Scanning-Electron-Microscopy (FIB-SEM), and load-to-fracture. Ageing was shown to have limited influence on the evaluated zirconia implant, with increased monoclinic content after loading/ageing being to a shallow transformed zone of ~2 µm at the implant surface. However, OG implants showed a significantly decreased fracture load of 751 ± 231 N (CG: 995 ± 161 N; p = .046). These values enable clinical application, but the fact that one failure was recorded during cyclic fatigue along with the significant decrease in strength after cyclic loading/ageing suggest that there may be room for further optimization of especially the PEKK abutment. Furthermore, good agreement was observed between the fracture modes of the implant that failed during the cyclic fatigue experiment and the in vivo failure of one implant during pre-clinical trials, validating the interest of the in vitro protocol used in this work to check the reliability of zirconia implant.