A retrospective cohort study on dental implant survival in patients with grafted alveolar clefts.

OBJECTIVES: The aim of this study was to assess the survival rate of dental implants inserted in an alveolar cleft area where one or more bone graft procedures were performed and to identify possible factors that affect the survival rate. MATERIALS AND METHODS: The available data from 78 implants placed in 64 patients with grafted alveolar clefts were retrospectively analysed. Statistical analyses were performed using Kaplan-Meier survival analysis, log-rank tests and univariable Cox proportional hazard models. RESULTS: The median follow-up period from insertion to the last follow-up appointment was 46 months (IQR: 29-79.3). In five patients, a single implant failed. This resulted in a cumulative survival rate of 95.0% at median follow-up. The factors investigated in this study did not have a significant effect on implant survival. CONCLUSIONS: Dental implants placed in patients with alveolar clefts are a reliable treatment option for dental rehabilitation.

Group 5 ITI Consensus Report: Implant placement and loading protocols.

OBJECTIVES: Working Group 5 was convened to discuss and find consensus on the topics of implant placement and loading protocols associated with single missing teeth in the anterior maxilla (aesthetic zone). Consensus statements, clinical recommendations, patient perspectives and future research suggestions were developed and presented to the plenary for discussion and approval. MATERIALS AND METHODS: Two systematic reviews were developed and submitted prior to the conference. The group considered in detail the systematic reviews and developed statements, clinical recommendations, patient perspectives and future research suggestions based on the findings of the reviews and experience of group members. Definitive versions were developed after presentation to and discussion by the plenary. RESULTS: Five consensus statements were developed and approved from each systematic review. Twelve clinical recommendations were developed by the group based on both reviews and experience. Three patient perspectives were developed, and five suggestions made for future research. CONCLUSIONS: Based on the findings of the systematic reviews and experience of group members, the Type 1A protocol (immediate placement and immediate loading), when utilized in the anterior maxilla under favorable conditions, is considered predictable and is associated with high survival rates. The procedure is considered clinically viable and is associated with aesthetic outcomes, although surgical, technical, and biological complications can occur.

Randomized Clinical Trial comparing clinical adjustment times of CAD/CAM screw-retained posterior crowns on ti-base abutments created with digital or conventional impressions. One-year follow-up.

OBJECTIVES: The purpose of this randomized clinical trial was to compare the required time of potential clinical adjustments of posterior screw-retained monolithic zirconia implant retained crowns based on intraoral optical scanning (IOS) or conventional impressions. MATERIALS AND METHODS: Patients with posterior tissue level implants (Straumann RN) replacing solitary teeth were recruited. Of all patients, impressions were taken with both an IOS (3M™ TDS) and a conventional (polyether) pick-up impression. Randomization was performed after impression taking and patients were to receive either a crown based on the digital or the conventional impression. The time required for adjustments at placement was recorded. Additionally, restoration survival and mechanical complications with a follow-up of one year were documented. RESULTS: Thirty two patients with 45 implants were included: 23 restorations in the test (IOS) and 22 in the control (conventional) group. The average adjustment time was 3.35 min (SD ± 3.38, range: 0-11 min) for the digital versus 6.09 min (SD ± 4.63, range: 0-18 min) for the conventional impressions (p = .039). A proper fit (no adjustments required) was achieved 39,1% in the digital and 18,2% conventional group respectively. All 45 restorations could be placed within the two planned appointments and only two minor mechanical complications occurred during the first year of function. CONCLUSIONS: The use of IOS resulted in shorter adjustment times at try-in than conventional impressions for solitary CAD/CAM implant restorations. Screw-retained solitary monolithic zirconia restorations on ti-base abutments show low complication- and survival rates in the short term.

Computer-assisted bone reduction and static computer-guided implant surgery in a fully edentulous patient: a technique report.

Computer-assisted implant surgery is one of the techniques that has gained much popularity over the past years. The amount of information that can be managed in a virtual environment allows for a faster, safer, and more precise implant placement. In certain cases, an appropriate implant-supported rehabilitation is accompanied by the need for complementary surgical procedures. The present technique report describes a clinical situation in which a bone reduction template and a stackable implant placement guide were digitally designed and 3D printed for a simultaneous ridge ostectomy and computer-assisted implant placement.

The accuracy of computer-guided implant surgery with tooth-supported, digitally designed drill guides based on CBCT and intraoral scanning. A prospective cohort study.

OBJECTIVES: The purpose of this prospective cohort study was to evaluate computer-guided implant surgery with tooth-supported drill guides based on CBCT scans and intraoral scanning. MATERIALS AND METHODS: For partially edentulous patients, a prosthetic and surgical planning was completed in the guided surgery software (coDiagnostiX) and drill guides were 3D-printed accordingly. Three months after implant placement, an intraoral scan of the implant's position was used to evaluate the accuracy of placement using the coDiagnostiX treatment evaluation tool. Deviations were reported in degrees and in distance at implant's entry point and apex. Several risk factors, which might influence the accuracy, were evaluated separately: treated jaw, flap design, prior augmentations, amount of unrestored teeth, crowding, location of implants, cortical interference, and implant's length and diameter. RESULTS: A total of 66 patients received 145 Straumann tissue level implants that were eligible for accuracy analysis. The mean angular deviation was 2.72° ± 1.42. The mean three-dimensional deviation at the implant's entry point was 0.75 mm ± 0.34. At implant's apex, the mean was 1.06 mm ± 0.44. The amount of unrestored teeth (p = .002 & p = .003), the implant's location (p < .001), the implant's length (p = .004), and cortical interference (p = .033) had a significant influence on the accuracy of placement. Implant survival was 99.3% (n = 1 failed implant) at 12 and 24 months. CONCLUSIONS: Guided surgery with tooth-supported drill guides made in a digital workflow is a feasible treatment option. However, deviations do occur and the implant's length, location, cortical interference and the amount of unrestored teeth have a significant influence on the accuracy.

The accuracy of static computer-aided implant surgery: A systematic review and meta-analysis.

OBJECTIVES: To assess the literature on the accuracy of static computer-assisted implant surgery in implant dentistry. MATERIALS AND METHODS: Electronic and manual literature searches were conducted to collect information about the accuracy of static computer-assisted implant systems. Meta-regression analysis was performed to summarise the accuracy studies. RESULTS: From a total of 372 articles. 20 studies, one randomised controlled trial (RCT), eight uncontrolled retrospective studies and 11 uncontrolled prospective studies were selected for inclusion for qualitative synthesis. A total of 2,238 implants in 471 patients that had been placed using static guides were available for review. The meta-analysis of the accuracy (20 clinical) revealed a total mean error of 1.2 mm (1.04 mm to 1.44 mm) at the entry point, 1.4 mm (1.28 mm to 1.58 mm) at the apical point and deviation of 3.5°(3.0° to 3.96°). There was a significant difference in accuracy in favour of partial edentulous comparing to full edentulous cases. CONCLUSION: Different levels of quantity and quality of evidence were available for static computer-aided implant surgery (s-CAIS). Based on the present systematic review and its limitations, it can be concluded that the accuracy of static computer-aided implant surgery is within the clinically acceptable range in the majority of clinical situations. However, a safety marge of at least 2 mm should be respected. A lack of homogeneity was found in techniques adopted between the different authors and the general study designs.

Group 5 ITI Consensus Report: Digital technologies.

OBJECTIVES: Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer-aided implant surgery (s-CAIS) and patient-related outcome measurements when using s-CAIS were addressed. MATERIALS AND METHODS: The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted. RESULTS: Static computer-aided surgery (s-CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s-CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent. CONCLUSIONS: Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s-CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s-CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care.

Current state of the art of computer-guided implant surgery.

The invention of computerized axial tomography (now known as computerized tomography) and developments of interactive software to allow virtual planning, with the aim to guide the surgery precisely toward a specific target, has dramatically improved general, as well as oral, surgery. Virtual dental implant planning allows for a prosthetically driven approach, resulting in the best possible design of the prosthesis, better esthetics, optimized occlusion and loading. This approach has also changed the surgical paradigm of using extensive flaps to obtain a proper view of the surgical area because flapless implant surgery, with or without immediate loading, has become more predictable. Two types of guided implant surgery protocols - static and dynamic - are described in the literature. The static approach, better known as computer-guided surgery, refers to the use of a tissue-supported surgical template. This reproduces the virtual implant position directly from computerized tomographic data and this information can be converted to guide templates to be used during surgery, with or without raising a mucoperiosteal flap. Dynamic guided surgery, also called navigation, reproduces the virtual implant position directly from computerized tomographic data and uses motion-tracking technology to guide the implant osteotomy preparation. As the technology developed further, different levels of evidence were presented that showed various degrees of accuracy. Several protocols for guided surgery are available in the literature and are distinguished by different guide production techniques, methods of support and drilling/placement protocols. Currently, implant planning software using cone-beam computerized tomography data has made it possible to plan the optical implant position virtually the optimal implant position, taking the surrounding vital anatomic structures and future prosthetic requirements into consideration. This paper summarizes the evolution and ongoing trends in digital and virtual planning and in implant surgery. The purpose of this overview was to clarify the different concepts in guided surgery and their respective advantages, disadvantages and limitations. The outcome of guided surgery is assessed in terms of implant survival, precision and complications. Clinical cases are given to demonstrate briefly the workflow and clinical guidelines for safe use of these approaches.

The influence of initial mucosal thickness on crestal bone change in similar macrogeometrical implants: a prospective randomized clinical trial.

OBJECTIVE: The objective of this study was to evaluate crestal bone changes around bone- and tissue-level implants related to initial mucosal thickness. MATERIALS AND METHODS: Patients received at least 2 implants: one with the prosthetic abutment connection at the crestal bone level (MC) and one with the prosthetic abutment connection at 2.5 mm supra crestal (LC). Flap thickness measurements were taken using a periodontal probe after raising the buccal flap. Patients were divided into 2 groups according to the mucosal thickness-Group A (thickness, ≤2 mm) and Group B (thickness, >2 mm). RESULTS: Our study included 33 patients and 78 implants. Each patient received at least 1 implant of each type: Group A (MC), 17 implants, with a mean bone change of -0.6 ± 0.5 mm; Group B (MC), 20 with a mean bone change of -0.2 ± 0.4 mm; Group A (LC), 15 with a mean bone change of -0.1 ± 0.5 mm; and Group B (LC), 22 with a mean bone change of -0.2 ± 0.4 mm. A paired-samples t-test for groups A (MC) and B (MC) yielded a statistically significant difference (P = 0.003); there was no statistically significant difference for groups A (LC) and B (LC) (P = 0.518). CONCLUSION: If the initial mucosal thickness surrounding bone-level implants is more than 2 mm, there is significantly less crestal bone change compared with bone-level implants placed in initial mucosal thicknesses of 2 mm or less. This difference is not statistically significant when tissue-level implants are used and the implant-abutment connection is 2.5 mm above the crestal bone level.

One-year results of maxillary overdentures supported by 2 titanium-zirconium implants - implant survival rates and radiographic outcomes.

OBJECTIVE: To assess implant survival rates and peri-implant bone loss of 2 titanium-zirconium implants supporting maxillary overdentures at 1 year of loading. MATERIAL AND METHODS: Twenty maxillary edentulous patients (5 women and 15 men) being dissatisfied with their complete dentures were included. In total, 40 diameter-reduced titanium-zirconium implants were placed in the anterior maxilla. Local guided bone regeneration (GBR) was allowed if the treatment did not compromise implant stability. Following 3 to 5 months of healing, implant-supported overdentures were inserted on two ball anchors. Implants and overdentures were assessed at 1, 2, 4, and 8 weeks after implant insertion and 2, 4, and 12 months after insertion of overdentures (baseline). Standardized radiographs were taken at implant loading and 1 year. Implant survival rates and bone loss were the primary outcomes. RESULTS: Nineteen patients (1 dropout) with 38 implants were evaluated at a mean follow-up of 1.1 years (range 1.0-1.7 years). One implant failed resulting in an implant survival rate of 97.3%. There was a significant peri-implant bone loss of the implants at 1 year of function (mean, 0.7 mm, SD = 1.1 mm; median: 0.48 mm, IQR = 0.56 mm). CONCLUSIONS: There was a high 1-year implant survival rate for edentulous patients receiving 2 maxillary implants and ball anchors as overdenture support. However, several implants exhibited an increased amount of bone loss of more than 2 mm. Overdentures supported by 2 maxillary implants should thus be used with caution as minimally invasive treatment for specific patients encountering problems with their upper dentures until more long-term data is available.

Randomized clinical study of the peri-implant healing to hydrophilic and hydrophobic implant surfaces in patients receiving anticoagulants.

OBJECTIVES: To compare the peri-implant bone healing between TiZr implants with hydrophilic SLActive and hydrophobic SLA implant surface in patients receiving anticoagulants, to assess the implant survival and success rate, as well as to evaluate whether small-diameter TiZr implants could be used in patients on OAT in order to avoid augmentation procedures. MATERIAL AND METHODS: A total of 80 small-diameter tissue-level TiZr implants with SLActive and SLA surfaces were placed in 20 anticoagulated patients, following the "split-mouth" study design. Implant stability was measured up to the third postoperative month by resonance frequency measurements (RFA). One-year implant survival and success rate were evaluated. RESULTS: After one year, 100% implant survival and success rate were observed. A significant decrease in ISQ comparing to baseline values was noted in the SLActive group from the first postoperative week, and in the SLA group, from the 3rd week after the surgery. In both groups, a statistically significant decline in ISQ was observed between second and third postoperative week. No significant differences in ISQ values between SLActive and SLA implants were noted, at any time point. CONCLUSIONS: Titanium-zirconium small-diameter implants with SLActive and SLA surface predictably achieve and maintain adequate bone tissue integration in patients receiving anticoagulants. OAT appears to influence the bone healing events resulting in lower ISQ in the end of 3-month period in comparison with baseline values, although without compromising implant stability.

A digital approach integrating facial scanning in a CAD-CAM workflow for complete-mouth implant-supported rehabilitation of patients with edentulism: A pilot clinical study.

STATEMENT OF PROBLEM: Complete-mouth implant-supported rehabilitations are challenging because of the multiple surgical and prosthetic steps involved in clinical evaluations to assure passive prosthesis fit and optimal esthetic and functional outcomes. As a result, these rehabilitations are usually associated with substantial clinical time, patient discomfort, and high treatment cost. PURPOSE: The purpose of this pilot clinical study was to evaluate a novel digital approach integrating digital intraoral dental and extraoral facial scanning information to design and mill a computer-aided design and computer-aided manufacturing (CAD-CAM) implant-retained prosthesis for patients with complete edentulism. MATERIAL AND METHODS: Ten patients in need of complete-mouth rehabilitation were included in this pilot study. Digital intraoral records were obtained through optical scanning the duplicate interim prosthesis using a laboratory scanner, while digital extraoral records were obtained through facial scanning using an in-office scanner. The scanned impressions and occlusal records were used to create a virtual tooth arrangement, which was matched to the patient's 3-dimensional face scan to create a virtual clinical evaluation phase. After applying the necessary adjustments, the virtual arrangement was submitted to a CAM procedure where a 5-axis industrial milling machine was used to fabricate an interim prosthesis. RESULTS: Digital intraoral and extraoral records were integrated and used to fabricate CAD-CAM milled interim prostheses, which were inserted and assessed for clinical fit, occlusion/articulation, and esthetics. The prostheses remained in function for at least 6 months with no notable technical or biological complications except for 1 prosthesis that fractured. CONCLUSIONS: A novel digital workflow incorporating facial scanning in a CAD-CAM workflow was used to fully digitally design and mill 10 implant-retained interim prostheses. More research is required to further develop and assess the accuracy and applicability of this approach.

Crestal bone changes in macrogeometrically similar implants with the implant-abutment connection at the crestal bone level or 2.5 mm above: a prospective randomized clinical trial.

OBJECTIVE: Crestal bone loss around dental implants is a criterion for success as this could prevent loss of implant and superstructure. The macrogeometry of the implant could influence bone remodelling when the implant-abutment connection is placed at crestal bone level or above. The aim of this study was to evaluate crestal bone remodelling in a randomized clinical prospective trial in macrogeometrically similar implants with the prosthetic connection at the crestal bone level and 2.5 mm above. The null hypothesis was that there was no difference in crestal bone loss after 1 year of early loading. MATERIAL AND METHODS: Patients were referred to Academic Centre of Dentistry Amsterdam for implant placement. Patients were subjected to inclusion and exclusion criteria and received a minimum of two implants: an implant with the prosthetic abutment connection at the crestal bone level (minimized collar [MC], bone level) and one with the prosthetic abutment connection 2.5 mm supracrestal (long collar [LC], tissue level). The mesial or distal location of each implant type was blinded for the patient and randomized. The implants were loaded splinted after 3 weeks of healing. The primary outcome was bone-level change assessed after 1 year of loading. RESULTS: Thirty-three patients fulfilled the inclusion criteria. Thirty-nine Thommen SPI ELEMENT LC implants and 39 MC were placed, and each fixed dental prosthesis was supported by one LC and one MC implant. The intraclass correlation of measures performed by the first and second X-ray examiner was as follows: on the mesial side of the MC implant 0.990 (0.980-0.995; 95% confidence interval [CI]), 0.980 (0.962-0.990; 95% CI) on the distal side of the MC implant, 0.979 (0.959-0.989; 95% CI) and 0.988 (0.978-0.994; 95% CI) on the mesial and distal side of the LC implant, respectively. The mean bone loss of the MC implant was 0.4 ± 0.4 mm. The mean bone loss of the LC implant was 0.2 ± 0.5 mm. The paired samples t-test showed a statistically significant difference (P < 0.05) between the MC and LC implants. CONCLUSION: Dental implants at bone level show statistically significantly (P < 0.05) more crestal bone change after 1 year of loading than a tissue-level implant.

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

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

Impact of Harvesting Method and Donor Age on the Behavior of Human Osteoblast-Like Cells.

Autogenous particulate bone grafts are being utilized in oral implantology for minor grafting procedures. This study aimed to investigate the influence of the bone-harvesting technique, donor age, and donor site on proliferation and differentiation of human primary osteoblast-like cells in the cell culture. Autogenous bone particles (20 samples) were harvested from the maxilla and mandible during surgery using two different protocols, and two types of particulate bone grafts were collected: bone chips and bone sludge. Bone samples were cultured in growth medium and, after 2 to 3 weeks, the cells that grew from bone grafts were cultured in the normal and osteogenic medium for 0, 4, 7, and 20 days. DNA, alkaline-phosphatase (ALP), calcium-content measurements, and Alizarin red/toluidine blue staining were performed. Data were analyzed by repeated-measures analysis of variance with Bonferroni test. The level of statistical significance was set at 5% (P < .05). Total DNA, ALP, and calcium content were significantly higher for the bone chip samples compared to the bone sludge samples. Total DNA and ALP content were significantly higher for the patients in age group 1 (≤ 60 years) compared to age group 2 (> 60 years) and was significantly higher for mandibular samples than maxillary samples on day 20. However, the calcium measurement showed no significant difference concerning donor age and donor site. Data analysis revealed that harvesting technique (bone chips vs bone sludge), donor age (≤ 60 years vs > 60 years), and donor site (maxilla vs mandible) influenced the osteogenic potential of the collected particulate bone graft. The bone chips were superior in terms of osteogenic efficacy and should be considered a suitable option for particulate bone graft collection.

A Randomized Clinical Trial comparing the clinical fit of CAD/CAM monolithic zirconia Fixed Dental Prostheses (FDP) on ti-base abutments based on digital or conventional impression techniques. One year follow-up.

PURPOSE: To compare the fit and clinical performance of screw-retained monolithic zirconia implant fixed dental prostheses (FDPs) based on either intraoral optical scanning (IOS) or conventional impressions. MATERIALS AND METHODS: Patients with two posterior tissue-level implants (Straumann Regular Neck) replacing two or three adjacent teeth were recruited. Impressions were taken with both IOS (True Definition Scanner, 3M ESPE) and a conventional (polyether) pick-up impression. Double-blind randomization was performed after impression-taking, and patients were to receive an FDP based on either the digital or the conventional impression. The fit was evaluated, and the time required for adjustments was recorded. Additionally, survival and technical complication rates with a follow-up of 1 year were documented. RESULTS: A total of 38 patients requiring 45 FDPs were included: 24 FDPs in the test (IOS) and 21 in the control (conventional) group. The average adjustment time was 6.92 minutes (SD: ± 10.84, range: 0 to 49 minutes) for digital vs 12.38 minutes (SD: ± 14.52, range: 0 to 54 minutes) for conventional impressions (P = .090). A proper fit (no adjustments) was achieved in 33.3% of the digital and 28.6% of the conventional group. Forty-two FDPs could be placed within the two planned appointments, and 3 FDPs exhibited an unacceptable fit and required an extra appointment. Eight technical complications occurred during the first year of function. The overall restoration survival rate was 100%. CONCLUSION: The clinical fit of CAD/CAM FDPs based on digital impressions is comparable to conventional impressions. Screw-retained monolithic zirconia FDPs on Ti-base abutments show low major complication and survival rates in the short term.

Additive Manufacturing of Zirconia Ceramic and Its Application in Clinical Dentistry: A Review.

Additive manufacturing (AM) has many advantages and became a valid manufacturing technique for polymers and metals in dentistry. However, its application for dental ceramics is still in process. Among dental ceramics, zirconia is becoming popular and widely used in dentistry mainly due to its outstanding properties. Although subtractive technology or milling is the state of art for manufacturing zirconia restorations but still has shortcomings. Utilizing AM in fabricating ceramics restorations is a new topic for many researchers and companies across the globe and a good understanding of AM of zirconia is essential for dental professional. Therefore, the aim of this narrative review is to illustrate different AM technologies available for processing zirconia and discus their advantages and future potential. A comprehensive literature review was completed to summarize different AM technologies that are available to fabricate zirconia and their clinical application is reported. The results show a promising outcome for utilizing AM of zirconia in restorative, implant and regenerative dentistry. However further improvements and validation is necessary to approve its clinical application.

Outcomes of dental implants in young patients with congenital versus non-congenital missing teeth.

OBJECTIVE: This cross-sectional study aims to investigate the effect of the cause of missing teeth on the survival and subjective success of dental implant treatment (DIT) in young patients with missing teeth due to non-congenital causes (tooth loss) in comparison to patients with missing teeth because of congenital causes (hypodontia and oligodontia). MATERIAL AND METHODS: All patients were asked 7 questions to extract information about the survival and subjective success of DIT. Implant survival function was designed using the Kaplan-Meier analysis. Differences in implant success outcomes were studied using binary logistic regression analysis. RESULTS: One hundred ten patients aged 18 to 40 years old were included, whereof 32 patients with tooth loss, 25 patients with hypodontia and 53 patients with oligodontia. In the tooth loss group, implant survival reached 96.9%; in the hypodontia group 96.0%; and in the oligodontia group 88.7%. Regarding subjective implant success, patient satisfaction was significantly higher (p < 0.040) among patients with congenital missing teeth in comparison to patients with tooth loss. Other implant success components showed no statistically significant difference (p > 0.050) between the groups. CONCLUSION: The cause of missing teeth does not influence implant survival. However, the cause of missing teeth does have a significant impact on patient satisfaction (implant success), ascertaining young patients with congenital missing teeth as more satisfied of DIT than young patients with tooth loss. CLINICAL RELEVANCE: Young patients with tooth agenesis and with an increased number of missing teeth are more content about the treatment with dental implants than patients with tooth loss. Furthermore, a consensus regarding the assessment of implant success is an essential concern for clarification.

A Prospective Randomized Clinical Trial on Radiographic Crestal Bone Loss Around Dental Implants Placed Using Two Different Drilling Protocols: 12-Month Follow-up.

PURPOSE: There is a substantial need to perform studies to evaluate crestal bone loss (CBL) and implant success when using a newly introduced low-speed drilling protocol. Therefore, this study aimed to evaluate the mean CBL and implant success rate by placing implants utilizing two drilling protocols, ie, standard and low-speed drilling protocols. MATERIALS AND METHODS: A randomized controlled clinical trial was carried out in patients who required dental implants to restore their esthetics and function. The patients were recruited from a university hospital (Academic Centre for Dentistry Amsterdam [ACTA], the Netherlands). Based on the inclusion criteria, patients were randomized to two study groups: (1) control group, standard drilling protocol; and (2) test group, low-speed drilling protocol without saline irrigation. The mean CBL and the implant success rate were evaluated after 12 months of implant placement. RESULTS: Twenty-three patients (15 men and 8 women with a mean age of 57.5 ± 10.7 years) contributed to the study. Forty Camlog screw-line implants were placed (20 implants per study group). After 12 months of implant placement, the mean CBL of implants placed with the standard protocol and the low-speed protocol was 0.206 ± 0.251 mm and 0.196 ± 0.178 mm, respectively. No statistically significant difference could be recorded among both groups (P = .885). Concerning implants placed in the maxilla, the standard drilling group and low-speed drilling group showed a mean CBL of 0.252 ± 0.175 mm and 0.251 ± 0.175 mm, respectively, compared with 0.173 ± 0.210 mm and 0.141 ± 0.172 mm in the mandible, with no significant difference. The success rate of dental implants at 12 months was 95% in the control group and 90% in the test group. CONCLUSION: Within the limitations of this study, it can be concluded that implants placed with the low-speed drilling protocol without saline irrigation exhibited a similar CBL compared with implants placed with the standard drilling protocol. However, a higher success rate was recorded especially in type 1-quality bone for the control group compared with the test group. Further randomized clinical trials with greater sample sizes and extended follow-up times should be performed to obtain stronger evidence and a better understanding of the influence of drilling speed on mean CBL and long-term implant success.

Parameters of passive fit using a new technique to mill implant-supported superstructures: an in vitro study of a novel three-dimensional force measurement-misfit method.

PURPOSE: The objectives of this study are to describe, in vitro, a novel technique to measure the misfit of digitally designed and manufactured implant-supported frameworks according to a new concept based on computer-guided surgery in combination with previously placed mini-implants. Also, the digitally created framework and an impression-based milled structure were compared using strain gauge measurements. MATERIALS AND METHODS: Acrylic resin and plaster models were prepared to represent the edentulous mandible. After insertion of three mini-implants in the acrylic resin model, a cone-beam computed tomographic scan was performed. The data were imported to planning software, where six implants were virtually inserted. A drill guide and titanium framework were designed and milled using a fully digital computer-aided design/computer-assisted machining protocol. Six implants were inserted using the drill guide attached to the mini-implants. After an impression was made of the acrylic resin model with six implants, the second model (plaster model) was prepared. A second milled titanium structure was fabricated following optical scanning of the acrylic resin model. Strain gauge measurements were done on both structures attached to both models. To validate the results, a high-accuracy industrial optical scanning system was used to capture all connection geometry and the measurements were compared. RESULTS: The accuracy of the digital superstructures was 19, 22, and 10 Microm with standard deviations (SD) of 19.2 (17.9), 21.5 (28.3), and 10.3 (10.1) Microm for the x-, y-, and z-axes, respectively. For the impression-based superstructure the measured misfit was 11, 20, and 17 Microm, with SD 11.8 (10.5), 19.7 (11.7), and 16.7 (8.2) Microm for the x-, y-, and z-axes, respectively. CONCLUSION: The misfit of the digitally designed and produced superstructure on the digitally planned and inserted implants was clinically insignificant.