Mechanical performance of patient-specific prefabricated temporary shell versus laboratory-fabricated CAD/CAM provisional implant-supported single-tooth restorations: A laboratory study.

OBJECTIVE: To evaluate the mechanical performance of patient-specific prefabricated temporary shell versus laboratory-fabricated CAD/CAM provisional restorations on titanium temporary abutments, with and without thermo-mechanical ageing. MATERIALS AND METHODS: Implants with a conical connection were divided into four groups (n = 24) and restored with temporary shell or laboratory-fabricated central or lateral incisor PMMA restorations that were relined or bonded on titanium temporary abutments. The diameter of the central and lateral incisor groups' implants was regular (ϕ 4.3 mm) or narrow (ϕ 3.5 mm), respectively. Half of each group's specimens were subjected to ageing, simultaneous thermocycling (5-55°C) and chewing simulation (120,000 cycles, 50 N, 1.7 Hz) resulting in eight groups in total (n = 12). The aged specimens were evaluated with optical microscopy, and survival and complication rates were determined according to modified USPHS criteria. The non-aged specimens and those that had survived ageing were loaded until failure, whereupon bending moments were calculated. RESULTS: Survival rates after ageing were 100% for all groups. Apart from wear facets (ϕ 2-3 mm) on the palatal restoration surface, no complications were observed. The mean fracture load and bending moments ranged between 597.6-847.1 N and 433.3-550.6 Ncm, respectively, with no significant differences between the eight groups (p = .25; p = .20). CONCLUSIONS: As patient-specific temporary shell central and lateral incisor provisional implant-supported restorations are mechanically stable enough to withstand clinical bite forces, even after thermo-mechanical ageing, they may serve as an alternative to laboratory-fabricated provisional restorations.

Immediate implant placement with immediate or delayed provisionalization in the maxillary aesthetic zone: A 10-year randomized trial.

AIM: To compare the marginal bone level of immediately placed implants, with either immediate or delayed provisionalization (IP or DP), in the maxillary aesthetic zone after 10 years of function. MATERIALS AND METHODS: Participants with a failing tooth in the maxillary aesthetic zone were randomly assigned to immediate implant placement with either IP (n = 20) or DP (n = 20) after primary wound closure with a free gingival graft. The final restoration was placed 3 months after provisionalization. The primary outcome was change in marginal bone level. In addition, implant survival, restoration survival and success, peri-implant tissue health, mucosa levels, aesthetic indices, buccal bone thickness and patient satisfaction were evaluated. RESULTS: After 10 years, the mean mesial and distal changes in marginal bone level were -0.47 ± 0.45 mm and -0.49 ± 0.52 mm in the IP group and -0.58 ± 0.76 mm and -0.41 ± 0.72 mm in the DP group (p = .61; p = .71). The survival rate was 100% for the implants; for the restorations, it was 88.9% in the IP group and 87.5% in the DP group. Restoration success, according to modified USPHS criteria, was 77.8% in the IP group and 75.0% in the DP group. The prevalence of peri-implant mucositis was 38.9% and 35.7% and of peri-implantitis 0.0% and 6.3%, respectively, in the IP group and DP group (p = 1.0; p = .40). The Pink Esthetic Score and White Esthetic Score was 15.28 ± 2.32 in the IP group and 14.64 ± 2.74 in the DP group, both clinically acceptable (p = .48). The buccal bone thickness was lower in the DP group. Patient satisfaction was similar in both groups (p = .75). CONCLUSIONS: The mean marginal bone level changes after immediate implant placement with IP were similar to those after immediate placement with DP. CLINICAL TRIAL REGISTRATION: Registered in the National Trial Register (NL9340).

Digital versus conventional surgical guide fabrication: A randomized crossover study on operator preference, difficulty, effectiveness, and operating time.

AIM: If surgical guide fabrication is introduced in a dental education program, a digital and conventional workflow can be used. This study evaluated operator preference, perceived difficulty and effectiveness and operating time of both fabrication methods. MATERIALS AND METHODS: Forty participants in a university setting (students, n = 20; dentists, n = 20) with varying levels of dental experience, but no experience in surgical guide fabrication, were randomly assigned to consecutively fabricate surgical guides on a standardized training model, with either the digital or conventional workflow first. The operating time was measured, and operator preference and the perception of difficulty and effectiveness were assessed with a questionnaire. T tests were used for statistical analysis (α = .05). RESULT: Of the students, 95% preferred the digital workflow and of the dentists 70%. The perceived difficulty of the digital workflow was significantly lower than the conventional workflow in the student group. Both groups perceived the digital workflow to be more effective. The mean operating time (mm:ss) amounted 12:34 ± 2:24 (students) and 18:07 ± 6:03 (dentists) for the digital, and 22:20 ± 3:59 (students) and 20:16 ± 4:03 (dentists) for the conventional workflow. CONCLUSION: Both students and dentists prefer the digital workflow for surgical guide fabrication. Students perceive the digital workflow as less difficult and more effective than the conventional workflow. The operating time for surgical guide fabrication is shorter with a digital workflow. This study indicates that digital fabrication techniques for surgical guides are preferred to be incorporated into the dental curriculum to teach students about treatment planning in implant dentistry.

Digital Workflow for Immediate Implant Placement and Chairside Provisionalization in the Esthetic Zone.

Introduction: Immediate implant placement and immediate chairside provisionalization in the esthetic zone require meticulous treatment planning. A digital workflow that combines intraoral scans and a cone beam computed tomography scan can be used to visualize the surgical and restorative aspects of the treatment and to plan a prosthetically driven implant position. A digital workflow in implant dentistry enables the prefabrication of an individualized CAD/CAM temporary restoration, based on the planned implant position. This could be a predictable method to deliver a screw-retained temporary restoration, directly after static computer-assisted immediate implant surgery. Interventions. Three patients with a failing tooth in the maxillary esthetic zone were treated with immediate implant placement and chairside provisionalization using this digital workflow. After 3 months, a final restoration was placed. Clinical, radiographic, and patient-reported outcome measures were collected prior to implant treatment, 6 weeks after placing the temporary restoration and then 1 month and 1 year after placing the final restoration. Outcomes. At the 1-year follow-up, healthy soft tissues were observed, and peri-implant bone levels were stable. Patient satisfaction after the treatment was high. Conclusion: The three reported cases demonstrate the potential for predictable immediate implant placement and chairside provisionalization using a digital workflow.

Monolithic zirconia single tooth implant-supported restorations with CAD/CAM titanium abutments in the posterior region: A 1-year prospective case series study.

PURPOSE: To assess the clinical, radiographic, and patient-reported outcome measures, including the success of screw-retained monolithic zirconia implant-supported restorations with CAD/CAM titanium abutments in the posterior region during a 1-year follow-up. METHODS: In a prospective case series, 50 molar sites in the posterior region of 46 patients with a minimum age of 18 years and sufficient bone volume and anatomical conditions for placing an implant (≥8 mm) and an anatomical restoration were included. Parallel-walled implants with a conical connection were inserted in a two-stage surgical procedure. Implant uncovering and healing abutment placement occurred 12 weeks after insertion. Two weeks after mucosa healing, a screw-retained monolithic zirconia restoration with a CAD/CAM titanium abutment was placed. Clinical, radiographic, and patient-reported outcome measures were collected at baseline before implant placement and then during the 1 month and 1 year follow-ups. RESULTS: At the 1 year follow-up, 49 restorations could be evaluated. The plaque accumulation, presence of calculus, bleeding tendency and peri-implant inflammation indices were low, representing healthy peri-implant conditions. The mean marginal bone level change between the 1 month and the 1 year follow-up was -0.17 ± 0.46 mm. The mean patient satisfaction was high. The restoration success was, according to the modified USPHS criteria, 95.9%. CONCLUSION: Monolithic zirconia implant-supported restorations with CAD/CAM titanium abutments have very good clinical, radiographic and patient-reported outcomes after 1 year in function.