Implant rehabilitation of the esthetic area: A five-year retrospective study comparing conventional and fully guided surgery.

INTRODUCTION: To compare the clinical outcomes of anterior single maxillary implants placed using conventional or guided implant surgery. METHODS: In this retrospective clinical study 44 patients rehabilitated with a single anterior implant in the maxillary arch were included. Twenty-four implants were inserted applying a guided surgery approach (GS), and 20 applying a conventional freehand approach (CS). Outcome measures were: implant survival rate and complications; mean bone level (MBL) evaluated at surgery (T0), after 6 weeks (6 W), and after 1 year (1Y), 2 years (2Y), 3 years (3Y), 4 years (4Y), and 5 years (5Y); patients' satisfaction evaluated through a questionnaire filled out before surgery (BS) and at 1 week, 6 W, 2Y and 5Y; Pink esthetic score (PES) and white esthetic score (WES) evaluated at 1Y, 3Y and 5 Y. Significance of differences between groups were tested by Fisher's exact test, Mann-Whitney U test, and Wilcoxon's signed rank test. RESULTS: During the 5-year follow-up there were no drop-outs and no implant failed. No significant differences between groups were found in MBL. A significant difference between groups was found in VAS scores regarding speech at 2 years, aesthetics at 6 weeks, confidence at 1 week and 6 weeks, satisfaction at T0 and at 1 W, pain/comfort at 1 W and at 6 W; all VAS scores resulted significantly improved compared to baseline. No significant differences in WES were found, while significant differences in PES scores between CS and GS groups were found at 3 and 5 years (p value = 0.023 and 0.004 respectively) with better outcomes for GS. A significant difference over time was found in PES between 5-year and one-year values. CONCLUSIONS: Guided surgery and conventional surgery implants did not show any difference in MBL during the 5-year observation period. Guided surgical procedure guarantee optimal esthetic outcome and seems able to guarantee better soft tissue result over time, even though more long-term studies are necessary to confirm this data.

Maximum insertion torque loss after miniscrew placement in orthodontic patients: A randomized controlled trial.

OBJECTIVES: To compare torque recordings of immediately loaded orthodontic miniscrews between insertion time and different post-placement timepoints (2 weeks, 4 weeks and removal time, respectively). SETTING AND SAMPLE POPULATION: Parallel trial with an allocation ratio of 1:1. Eligibility criteria were needs of fixed orthodontic treatment, no systemic disease and absence of using drugs altering bone metabolism. MATERIAL AND METHODS: Patients received miniscrews, 2.0 mm diameter and 10 mm length. All miniscrews underwent inter-radicular placement, and they were placed in the maxilla or in the mandible, palatally or buccally. No pre-drilling was performed. Miniscrews were loaded immediately after the insertion and were used for distalization, intrusion, extrusion, mesialization or indirect anchorage. Patients were randomly divided into three groups. For each patient, Maximum Insertion Torque (MIT) was evaluated at baseline. MIT was measured again after 2 weeks and after 4 weeks by tightening the screw a quarter of turn in Groups 1 and 2, respectively. At the end of the treatment, maximal removal torque was evaluated in Group 3. Torque variation with respect to insertion time was considered as the primary outcome. Baseline and longitudinal differences were tested using the linear mixed-effects (LME) model. RESULTS: Forty seven patients and 74 miniscrews were followed up. An association existed between maximum insertion torque and the observation time. A torque decrease of 26.9% and 30% after 2 weeks was observed for mandibular and maxillary miniscrews, respectively. After 1 month, torque values were similar to the baseline records. The overall success rate was 79.7%. No serious harm was observed. CONCLUSIONS: Maximum insertion torque undergoes a loss during the first 2 weeks, and its values may depend on the insertion site and the anchorage purpose. Removal torque value is almost the same as the initial torque after 1 month.

A digital workflow for computer-guided implant surgery integrating CBCT, model scanning, and CAD/CAM for a complete edentulism implant-supported prosthesis: a technique procedure.

The utilization of digital 3D surface images (STL format) for planning cases of computer-guided implant surgery is very useful in partially edentulous cases. In fully edentulous cases, however, the absence of teeth makes it necessary to add reference markers. The proposed protocol demonstrates a simple procedure that allows for the superimposition of STL and radiologic data (DICOM format). In the presented patient case, the tissue-bearing area of the prosthesis was relined with a polysulfide impression material and sent to the laboratory. A master cast was produced. The prosthesis was relined to improve intraoral stability and was provided with at least three radiopaque 3D markers. An STL copy of the prosthesis and the model was generated through a laboratory scanner. The patient wore the prosthesis with the attached markers during the 3D radiologic examination. In the planning software (CoDiagnostiX; Dental Wings), the prosthesis markers on the STL were matched to the corresponding markers visible on the DICOM data. Then, the STL of the model was matched to that of the prosthesis. Once the STL of the mucosa and the prosthesis were imported into the software, new possibilities arose, ie, the option to add other digital or traditional tooth setups to the same radiologic data or to design a surgical guide based on the actual mucosa of the patient.

Comparison of Cemented vs Screw-Retained, Customized Computer-Aided Design/Computer-Assisted Manufacture Zirconia Abutments for Esthetically Located Single-Tooth Implants: A 10-Year Randomized Prospective Study.

PURPOSE: To compare the clinical outcomes of screw-retained vs cemented single crowns supported by customized zirconia abutments on implants. MATERIALS AND METHODS: Thirty-two patients received implant-supported (Regular Neck, Tissue-Level, Straumann AG), single-tooth restorations with customized zirconia abutments in the anterior areas. Participants were randomly assigned to the screw-retained (full-crown abutment [FCA]) group or the cemented (zirconia crown [ZrC]) group and followed up over a 10-year period. Prosthetic and biologic complications, marginal bone level (MBL), mucosal recession, and pink and white esthetic scores (PES and WES, respectively) were evaluated. RESULTS AND CONCLUSION: There were no implant failures during the study period; after 10 years, 94% of crowns were functional. Prosthetic complications were recorded in both groups (three FCA and two ZrC), and no significant difference was found (P = .65). Two cases of mucositis were recorded, one in each group. Esthetic outcomes were assessed using PES and WES scores. MBL was 0.95 mm in the ZrC group and 0.82 mm in the FCA group, with no significant difference between groups. These encouraging preliminary results need to be confirmed with long-term follow-up on larger study samples.

Immediately Loaded Implants in Rehabilitation of the Maxilla: A Two-Year Randomized Clinical Trial of Guided Surgery versus Standard Procedure.

BACKGROUND: Implant-simulation software can now be used to improve treatment planning, guide surgery, and ensure more accurate implant placement. PURPOSE: The aim of this study was to evaluate the outcome of a guided surgery protocol versus a conventional protocol. MATERIALS AND METHODS: Twenty-six patients were randomly assigned to Guided Surgery or Conventional Surgery. In test group implants were placed in the maxilla using a tooth supported model-based surgical guide with a minimally invasive flap and immediately loaded. In control group implants were inserted with an open flap surgery following a prosthetic stent and immediately loaded. RESULTS: A total of 70 implants were placed (36 test and 34 control). Statistically significant differences were found between the test group and the control group for patient opinion about self-confidence, assumption of analgesic tablets and perceived pain. The test group registered a statistically significant reduction (p < .05) as regards time of surgery and time of provisional insertion with respect to the control group. CONCLUSIONS: Implants can successfully integrate in the posterior maxilla using a guided surgery approach with immediate loading. The use of guided surgery helped to reduce the surgery duration, pain intensity, related analgesic consumption, and a more predictable provisional installation.

Immediate versus delayed loading: comparison of primary stability loss after miniscrew placement in orthodontic patients-a single-centre blinded randomized clinical trial.

INTRODUCTION: The aim of this randomized clinical trial was to compare torque recordings at insertion time and 1 week post-placement between immediately loaded orthodontic miniscrews and an unloaded control group. TRIAL DESIGN: This RCT was designed as parallel with an allocation ratio of 1:1. METHODS: Eligibility criteria to enroll patients were: needs of fixed orthodontic treatment, no systemic disease, absence of using drugs altering bone metabolism. All patients were consecutively treated in a private practice and the miniscrews were placed by the same author. Patients received ORTHOImplant (3M Unitek) miniscrews and they were blindly divided in two groups: group 1 screws were unloaded between T0 and T1, group 2 received immediately loaded screws with NiTi coil. For each patient, maximum insertion torque (MIT) was evaluated at T0. After 1 week, without loading, the screw torque was measured again (T1) and at the end of the treatment maximal removal torque was evaluated (T2). Torque variation in the first week was considered as the primary outcome. RANDOMIZATION: A randomization list was created for the group assignment, with an allocation ratio of 1:1. BLINDING: The study was single blinded in regard of the statistical analysis. RESULTS: Patients enrolled in the clinical trial were 51 for a total of 81 miniscrews. The recruitment started in November 2012 and the observation period ended in August 2014. Twenty-six and twenty-five patients were analysed in group 1 and 2, respectively. The MIT mean in each placement time was 18.25 Ncm (SD = 3.00), 11.41 Ncm (SD = 3.51) and 10.52 Ncm (SD = 5.14) at T0, T1, and T2 time, respectively. In group 1, the torque decrease between T1 and T0 was statistically higher compared to group 2 (P value = 0.003). Statistically significant effects of the placement times on MIT were found (P value <0.0001). No serious harm was observed. LIMITATIONS: This study was performed using only direct force on the miniscrew and not using the miniscrew as an indirect anchorage. It was not possible to obtain quantitative data on bone quality or root proximity to miniscrews. CONCLUSIONS: A significant stability loss was observed in the first week in both groups; Group 1 showed a statistically higher torque loss in the first week when compared to the immediately loaded group. There were statistically significant effects of the measurement times on MIT and of the miniscrew location on MIT. The overall failure rate was 7.4%. TRIAL REGISTRATION: This trial was not registered. PROTOCOL: The protocol was not published before trial commencement.

Clinical and Aesthetic Outcome with Post-Extractive Implants with or without Soft Tissue Augmentation: A 2-Year Randomized Clinical Trial.

BACKGROUND: The aesthetic outcome of an implant-supported restoration is first of all dependent on the soft tissue volume. Because the labial bone plate resorbs in every direction after tooth extraction, even when an implant is placed immediately, most patients end up with compromised aesthetics. MATERIALS AND METHODS: In this parallel-designed, randomized clinical trial, participants were randomly assigned to the test group (immediate load post-extractive implant treated with subepithelial connective tissue graft placed using the tunnel technique in the labial area) and control group (immediate load post-extractive implant treated without raising a flap) with an allocation ratio of 1:1. Both groups received deproteinized bovine bone mineral. Patients were observed at baseline, crown insertion, 1-year follow-up, and 2-year follow-up. Clinical, radiological and aesthetic parameters were recorded to assess primary treatment outcomes. A random permuted block system was blindly generated ensuring uniformity of the patient allocation during the trial by randomly distributing three participants to the test and three participants to the control group every six treated patients. RESULTS: At the 2-year examination, all 47 implants were successfully integrated, demonstrating stability and healthy peri-implant soft tissues as documented by standard clinical parameters. The results showed a soft tissue remodeling of -10% in thickness and -18% in highness in the non-grafted group, whereas in the grafted group there was a gain of 35% in thickness and a slight reduction of -11% in highness. Test group reported an increase of aesthetic result (mean pink aesthetic score [PES] 8) compared with control group (mean PES 6.65). CONCLUSIONS: This prospective study demonstrates the effectiveness of placing a soft tissue graft at the time of immediate implant placement in the aesthetic zone. At the 2-year follow-up, test group revealed a better aesthetic outcomes and stable facial soft tissues compared with control group.

Block allograft technique versus standard guided bone regeneration: a randomized clinical trial.

PURPOSE: The aim of this randomized clinical trial was to compare the potential of deproteinized bovine bone added to autologous bone or corticocancellous allograft block with or without the addition of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) to regenerate mandibular atrophic ridges. TRIAL DESIGN: parallel, allocation ratio of 1:1 using a split-mouth model. Eligibility criteria for patients: adult patients; bilateral atrophic edentulous areas in the posterior area of the mandible; a preoperatory cone beam computed tomography scan; and absence of systemic diseases affecting the bone metabolism. Bone graft intervention for control group consisted of bone chips collected with a scraper mixed with deproteinized bovine bone covered with a resorbable membrane. Bone graft intervention for test group consisted of a corticocancellous allograft block, shaped before surgery, and protected with a collagen membrane. In addition, both groups received rhPDGF-BB or a saline solution as control. As primary outcome quantity, bone variation after a 1-year healing period was considered. A p-value of.05 was considered statistically significant. RESULTS: Sixteen patients were enrolled in this trial. A total of 50 implants and 32 bone grafts were placed. All patients concluded the study (no dropouts). Change at 1 year in bone volume was not significantly different between the two groups (p-value = .25). Effect of treatment in terms of change in bone volume at 1 year was not significant (p-value = .89) when saline solution was used while was at limit of significance when rhPDGF-BB was used (p-value = .052). After 1 year, all the implants were successfully integrated. CONCLUSIONS: The block allograft and the standard regenerative procedure showed similar results in terms of regenerated bone volume after 1 year of functional loading. The rhPDGF-BB positively influenced soft-tissue healing.

Internal bone temperature change during guided surgery preparations for dental implants: an in vitro study.

PURPOSE: The aim of this pig model study was to verify whether the use of devices (surgical templates) or procedures (flapless or flap) of guided surgery may cause a potentially pathologic increase of temperature during the bone preparation. MATERIALS AND METHODS: In this in vitro study, pig ribs with mean cortical thickness of 1.90 mm were used. Open-flap and flapless guided surgery (experimental groups OGS and FGS) and open-flap and flapless conventional technique (control groups OSS and OFS) were performed. Temperature changes were recorded at a distance of 0.5 mm from the final test osteotomy by 2 thermocouples at depths of 1.5 (point A) and 12 mm (point B). Data were collected from 80 measurements, 10 for each group. RESULTS: A statistically significant increase of temperature was reported for the FGS and OGS groups considering the measurement at point A (mean Δt 4.81 degrees and 4.21 degrees, respectively). The measurement at Point B for the FGS group compared to the FSS group did not differ significantly for the 3-mm drill, nor did the OSS group with the 2-mm drill. CONCLUSIONS: Site preparation with surgical stents generated higher bone temperature than conventional drilling. However, this heat generation did not reach temperature levels dangerous for the bone.

Rehabilitation of a dentate mandible requiring a full arch rehabilitation. Immediate loading of a fixed complete denture on 8 implants placed with a bone-supported surgical computer-planned guide: a case report.

The use of technologies that merge computerized tomography X-ray imaging and 3-dimensional (3D) planning software allow the surgeon to digitally elaborate on the computer the position, length, and diameter of every implant to be placed. Following this approach, the placement is guided in a 3D digital model, and the implants are placed in the final position avoiding eventual anatomic structures. In this case report, the patient's remaining mandibular teeth were extracted, and the patient received 8 implants with the help of a computer surgical guide. The case was planned using SimPlant and a bone-supported guide. Because of the high precision of the planning, it was possible to realize a provisional rehabilitation before the actual surgery. The planning allows placement of parallel implants to optimize the prosthetic procedure and outcome. An immediate provisional implant was fixed with a flow composite on the temporary abutments and then refined in the dental laboratory. The patient received the provisional rehabilitation the same day of the surgery. After 6 weeks of healing, the final impression was taken and the prosthesis was finalized with a computer-aided design/computer-aided manufacturing titanium full-arch screwed framework with composite veneering. A 6-month follow-up showed good integration of the prostheses and success of all 8 implants. The use of surgical computer-guided planning changes the surgeon's approach: whereas before the use of conventional guides permitted a certain degree of offset from what was planned, the use of computer guides allows the implant to be inserted in a far more precise way. It is obvious that careful planning is the key factor to avoid implant misplacement.

Clinical and radiographic evaluation of small-diameter (3.3-mm) implants followed for 1-7 years: a longitudinal study.

Implants with a small diameter may be used where bone width is reduced or in single-tooth gaps with limited mesiodistal space, such as for the replacement of lateral maxillary or mandibular incisors. The purpose of the present longitudinal study was to compare the prognosis of narrow implants (3.3-mm-diameter) to standard (4.1-mm-diameter) implants. Over a 7-year period, 122 narrow implants were inserted in 68 patients to support 45 partial fixed prostheses (PFD) and 23 single-tooth prostheses (ST). Furthermore, 120 patients received 208 standard implants and were restored with 70 PFD and 50 ST, respectively. Clinical and radiographic assessment data were provided. Six (1.8%) out of 330 implants failed. Cumulative survival and success rates were calculated with life-table analyses processed by collecting clinical and radiographic data. For narrow implants, the cumulative survival rate was 98.1% in the maxilla and 96.9% in the mandible. The cumulative success rate was 96.1% in the maxilla and 92% in the mandible. Conversely, standard-diameter implants showed a cumulative survival rate of 96.8% in the maxilla and 97.9% in the mandible. The cumulative success rate was 97.6% in the maxilla and 93.8% in the mandible. Cumulative survival and success rates of small-diameter implants and standard-diameter implants were not statistically different (P > 0.05). Type 4 bone was a determining failure factor, while marginal bone loss was not influenced by the different implant diameters. The results suggest that small-diameter implants can be successfully used in the treatment of partially edentulous patients.