Search

The objective of this study was to determine the influence of height and thickness of the one wall remaining coronal tooth structure on the fracture resistance of an endodontically treated root with resin abutment build-up using resin composite and fiber-reinforced resin composite post. Static and dynamic fracture tests were performed by placing the remaining tooth wall on the tensile side and applying loads at an angle of 30° from the tooth axis. Superior static fracture resistance was observed when the wall remaining on the tooth had a height and thickness greater than 1.0 mm. The dynamic fatigue test showed high loading capacity or fracture resistance in specimens with large height and thickness. The dynamic fatigue test showed the influence of the remaining tooth structure on fracture resistance clearly. In conclusion, the static and dynamic fracture resistances increased with the height and thickness of the one wall remaining tooth structure.

Owing to the satisfactory esthetic and functional outcomes of implant surgery for the anterior teeth, some dentists consider it the gold standard treatment. However, the risk of developing peri-implantitis is positively associated with the long-term use of the implant. This necessitates the development of an implant design that reduces the risk of peri-implantitis, considering the long-term use of implants in young patients. This case report describes a new approach for an implant surgery using a two-stage implant in a 28-year-old woman. Her clinical course was satisfactory during the 4-year postoperative follow-up period; no inflammation was noted in the surrounding tissues. The two-stage implants allow for the removal of an implant body from an infected area and its replacement with a new abutment if peri-implantitis develops in the future. This article is protected by copyright. All rights reserved.

BackgroundThe All-on-four dental implant method is an implantology method designed to provide a comfortable prosthetic treatment option by avoiding advanced surgical procedures. This research aims to compare and evaluate the stress and tension values in conventional angled multiunit abutment-implant connection systems and monoblock dental implants used in the all-on-four procedure with finite element analysis.MethodsTwo master models were created by placing four implants connected to multiunit abutments (group A) in the interforaminal region of a completely edentulous mandible and four monoblock implants (group B) in the same region of another completely edentulous mandible. Group A implants were classified according to their diameter as follows: 3.5 mm (M1A), 4.0 mm (M2A), and 4.5 mm (M3A). Similarly, group B implants were classified as M1B, M2B, and M3B. In the six models rehabilitated with acrylic fixed prostheses, a 100 N force was applied to the anterior implant region, and a 250 N force was applied to the posterior cantilever in both axial and 30° oblique directions. Von Mises stresses were analyzed in the bone and implant regions of all models.ResultsM1A and M1B, M2A and M2B, and M3A and M3B were compared with each other under axial and oblique forces. The maximum Von Mises stresses in the bone around implants and the prosthesis screws, and the maximum and minimum principal stresses in the cortical and trabecular bone in group A models were significantly higher than those in group B models.ConclusionsIn monoblock implant systems under axial and oblique forces, higher stress is accumulated in the bone, prosthesis screw and implant compared to multiunit abutment-implant connection systems.

Objective To characterize the biomechanical performance of fiber-reinforced composite 5-unit implant-supported fixed dental prostheses (FDPs) receiving individually milled crowns by insilico and fatigue analyses. Methods Eighteen implant-supported five-unit fiber-reinforced composite frameworks with an individually prepared abutment design were fabricated, and ninety resin-matrix ceramic crowns were milled to fit each abutment. FDPs were subjected to step-stress accelerated-life testing with load delivered at the center of the pontic and at 2nd molar and 1st premolar until failure. The reliability of the prostheses combining all loaded data and of each loaded tooth was estimated for a mission of 50,000 cycles at 300, 600 and 900 N. Weibull parameters were calculated and plotted. Fractographic and finite element analysis were performed. Results Fatigue analysis demonstrated high probability of survival at 300 N, with no significant differences when the set load was increased to 600 and 900 N. 1st and 2nd molar dataset showed high reliability at 300 N, which remained high for the higher load missions; whereas 1st premolar dataset showed a significant decrease when the reliability at 300 N was compared to higher load missions. The characteristic-strength of the combined dataset was 1252 N, with 1st molar dataset presenting higher values relative to 2nd molar and 1st premolar, both significantly different. Failure modes comprised chiefly cohesive fracture within the crown material originated from cracks at the occlusal area, matching the maximum principal strain location. Significance Five-unit implant-supported FDP with crowns individually cemented in a fiber-reinforced composite framework presented a high survival probability. Crown fracture comprised the main failure mode.

Objectives The aim of this prospective case series was to assess the implant outcomes as well as hard and soft tissue dimensional changes of immediate implant placement in posterior sites using a custom-made sealing socket abutment (SSA) combined to peri-implant socket filling (PISF). Material and methods Twenty patients were considered for single extraction and immediate implant in upper or lower posterior regions. The remaining peri-implant sockets were filled with Deproteinized Bovine Bone Mineral. Based on intra-oral scans (IOS), custom-made SSAs were placed the same day. Implant survival rate, peri-implant bone changes, peri-implant health and pink esthetic score (PES) were recorded up to 1 year post implant placement. Moreover, CBCT and IOS were performed to monitor hard and soft tissue dimensional changes. Results One implant failed to osseointegrate leading to an implant survival rate of 95% after 1 year. Peri-implant bone changes yielded 0.19±0.31 mm and 84.2% of the implants displayed no or mild bleeding on probing. Horizontal bone remodeling was not significant from baseline to 1 year at any levels. Finally, soft tissue profile was stable in the most cervical area while minor changes occurred during the first 6 months below the gingival margin. Absence of mid-buccal recession (0.07 mm) and good PES were found after 1 year. Conclusion Despite its limitations, this study showed that immediate implants in the posterior region using the SSA + PISF protocol resulted in promising implant outcomes with limited hard and soft tissue dimensional changes while decreasing the overall treatment time.

INTRODUCTION The computer-aided design/computer-aided manufacturing (CAD/CAM) technology has revolutionised dentistry at present. An operator's skills can affect the overall clinical duration and marginal accuracy of the prosthesis fabricated through this workflow. The aim of this study was to assess the effect of CAD/CAM hands-on training compared with that of a self-instructional video on the performance of dental students in digital impression and fabrication of a CAD/CAM crown. METHODS In this cross-sectional study, 30 undergraduate dental students were shown a CEREC demonstration video. Each operator then captured a digital impression using the intra-oral scanner, and a crown was subsequently milled. All participants underwent a training course before repeating the process. Marginal discrepancy for each crown on its abutment tooth was measured before and after training using a stereomicroscope and was evaluated using Wilcoxon signed rank test. The duration taken for the process was recorded before and after training and evaluated using paired t-test. RESULTS The overall mean ±standard deviation marginal adaptation for the CEREC crowns was 78.15 ± 42.83 μm before training and 52.41 ± 17.12 μm after training. The Wilcoxon signed rank test found significant difference (p

Objectives This study aimed to determine whether distally angulating an implant is a successful strategy to avoid the maxillary sinus and the need for bone augmentation, while increasing the anterior-posterior (A-P) implant distribution in the edentulous maxilla. Materials and methods In 115 patients with edentulous maxillae, virtual implant planning was performed utilizing cone-beam computer tomographs. Axial (8 mm length) and tilted (12 mm length) dental implants with 30-degree and 45-degree angulation were virtually positioned to avoid entering the maxillary sinus, while maximizing A-P distribution. Measurements were made between the tilted and axial implants to assess the change in A-P distribution of implants at the implant and abutment levels. Results Forty-seven sites (20.4%) were not able to have either treatment modality with insufficient bone for implant placement. Axial implants were placed more distally than 45-degree and 30-degree tilted implants in 24% and 42% of sites, respectively. The average change in A-P spread measured at the implant level, for 30- and 45-degree tilted implants was -0.25 mm (95% CI -0.76, 0.26) and 1.9 mm (95% CI 1.4, 2.3), respectively. When measured from the center of each multi-unit abutment the average increase in A-P distances for tilted implants appears larger in the 30-degree and 45-degree groups by 0.97 mm and 1.74 mm, respectively compared to measurements at the implant level. Conclusions Angulating 12 mm implants provides a limited increase in A-P distribution of implants in edentulous rehabilitation in most situations. In certain patients, the use of 8mm axial implants may provide a greater A-P spread.

Made available in DSpace on 2022-04-29T08:32:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Dental implants are widely used as a long-term treatment solution for missing teeth. A titanium implant is inserted into the jawbone, acting as a replacement for the lost tooth root and can then support a denture, crown or bridge. This allows discreet and high-quality aesthetic and functional improvement, boosting patient confidence. The use of implants also restores normal functions such as speech and mastication. Once an implant is placed, the surrounding bone will fuse to the titanium in a process known as osseointegration. The success of osseointegration is dependent on stress distribution within the surrounding bone and thus implant geometry plays an important role in it. Optimisation analyses are used to identify the geometry which results in the most favourable stress distribution, but the traditional methodology is inefficient, requiring analysis of numerous models and parameter combinations to identify the optimal solution. A proposed improvement to the traditional methodology includes the use of Design of Experiments (DOE) together with Response Surface Methodology (RSM). This would allow for a well-reasoned combination of parameters to be proposed. This study aims to use DOE, RSM and finite element models to develop a simplified optimisation analysis method for dental implant design. Drawing on data and results from previous studies, two-dimensional finite element models of a single Branemark implant, a multi-unit abutment, two prosthetic screws, a prosthetic crown and a region of mandibular bone were built. A small number of combinations of implant diameter and length were set based on the DOE method to analyse the influence of geometry on stress distribution at the bone-implant interface. The results agreed with previous studies and indicated that implant length is the critical parameter in reducing stress on cortical bone. The proposed method represents a more efficient analysis of multiple geometrical combinations with reduced time and computational cost, using fewer than a third of the models required by the traditional methods. Further work should include the application of this methodology to optimisation analyses using three-dimensional finite element models. Centre for Simulation in Bioengineering Biomechanics and Biomaterials (CS3B) Department of Mechanical Engineering Engineering College of Bauru (FEB) São Paulo State University (UNESP) Department of Mathematics Faculty of Science (FC) São Paulo State University, São Paulo State Centre for Simulation in Bioengineering Biomechanics and Biomaterials (CS3B) Department of Mechanical Engineering Engineering College of Bauru (FEB) São Paulo State University (UNESP) Department of Mathematics Faculty of Science (FC) São Paulo State University, São Paulo State

AIM The aim of this study was to assess the effectiveness of different gingival displacement materials in the management of the width of the gingival sulcus. MATERIALS AND METHODS Totally, 60 participants who were aged 18 years and more were chosen for this study. The eligible participants were those who required fixed prosthesis with at least one abutment. A modified sectional tray was used to make impressions with elastomeric materials along with additional polysilicon using the double mix single impression technique. All participants were divided randomly into three experimental groups with each group having 20 participants as follows: group I-Expasyl, group II-Magic Foam Cord, and group III-Traxodent. Soon after retraction, impressions were made and assessed in a comparable manner to pre-retraction impressions. Image analysis software was used to measure the quantity of displacement of the gingiva, marked as the distance from the tooth to the gingival crest in the horizontal level under stereomicroscope. RESULTS The highest mean sulcular gingival width (0.644 ± 0.22) was found in Traxodent group followed by Expasyl group (0.590 ± 0.11) and Magic Foam Cord group (0.528 ± 0.01). A statistically significant difference (p

The aim of this systematic review with meta-analysis was to compare the survival rate of single crowns supported by extra-short implants (≤ 6 mm) to those supported by conventional implants, with or without previous maxillary sinus augmentation. The proportion of failures was described according to the type of complication and follow-up periods. Materials and methods: Randomized and prospective clinical trials were selected from six databases and gray literature. The risk of bias was evaluated by Joanna Briggs Institute Critical Appraisal Checklist, and the certainty of the evidence was analyzed with Grading of Recommendations Assessment, Development, and Evaluation. Meta-analyses were processed with RevMan and MedCalc Statistical Software. Results: Single crowns supported by extra-short implants had a similar risk of failure to those supported by conventional implants, regardless of previous maxillary sinus augmentation (P > .05). Overall failure proportion of extra-short implants was 5.19%, but it varied according to follow-up (1.18% before loading, 1.56% at 12 months, 1.20% at 24 months, 2.10% at 48 months). Biologic failure complications were 37.90% for bleeding on probing, 22.45% for peri-implantitis, and 11.29% for infection. Prosthodontics failure complications were 14.88% for abutment failures and 14.73% for prosthetic screw loosening. Considering the risk of bias, most studies were classified at moderate risk. Conclusion: The risk of failure of single crowns supported by extra-short implants is similar to those supported by conventional implants, regardless of previous maxillary sinus augmentation or follow-up period. The most frequent biologic and prosthetic complications were bleeding on probing and abutment failures, respectively.

The purpose of this randomized clinical study was to evaluate the efficacy of platform-switching (PS) vs platform-matching (PM) implants when paired with a newly designed marginless abutment (MA) vs a conventional abutment (CA) in maintaining peri-implant tissue stability. Marginal bone level (MBL) and probing depth were measured up to 1 year postloading. Eighty implants were inserted in 42 patients and randomly assigned to one of four groups, each with a different implant/abutment configuration: Group 1 (PM+CA), Group 2 (PM+MA), Group 3 (PS+CA), and Group 4 (PS+MA). Data were collected at implant placement (T0), abutment placement (T1), final crown placement (T2), and 1 year postloading (T3). At the 1-year follow-up, MBL was more stable in Groups 3 and 4 compared to Groups 1 and 2. These results suggest that the role played by the implant-abutment connection (PS vs PM) is more important than the type of abutment preparation (MA vs CA).

Background The present study aims to assess the influence of low-level laser therapy (LLLT) on stability in implants placed in healed sites. Material and methods The present study followed the SPIRIT statement and is reported according to CONSORT. Patients were randomly allocated to LLLT or control groups. LLLT consisted in the application of 808-nm GaAlA laser applied before the preparation of the implant bed and after suturing (80 seconds; 11J/cm2). Implant stability quotient (ISQ) and the distance between the implant platform to the alveolar bone crest (millimeters) were assessed at implant placement (T0) and the abutment selection phase (4–6 months, Ta). Results A total of 64 implants were placed in 33 patients. The insertion torque ranged from 10 to 70 N.cm (mean 43.23; SD ±16.82). The T0 ISQ ranged from 18 to 95.5 (mean 61.7; SD ±18.23) and the crestal bone radiographic distance was 2.03 mm (SD±1.27). At Ta, the ISQ ranged from 39 to 90 (mean 64.2; SD±9.84), and the mean crestal bone radiographic loss was 1.70mm (SD±1.65). However, no differences were observed when LLLT and control groups were compared with ISQ difference (Ta–T0; p=0.598) or radiographical peri-implant alterations (p=0.531). Conclusion LLLT did not influence the implant stability in implants placed in healed sites compared to a control group. Trial registration ReBEC, RBR-35TNJ7. Registered May 23, 2018

PURPOSE To assess the short-term outcomes of two different conservative preparation designs for posterior zirconia inlay-retained fixed dental prostheses (IRFDPs) and to analyze the marginal integrity of such restorations. MATERIALS AND METHODS Thirty patients with a missing maxillary first molar participated in this study and were divided randomly into two groups: one that received abutment preparations for inlay retainers (ID group, n = 20), including a proximal box and an occlusal extension, and one that received only proximal box preparations (PB group, n = 10). Zirconia IRFDPs were bonded in position and followed up after 2 weeks, 6 months, 1 year, and then annually. The in situ restorations were duplicated utilizing a single-step putty/wash impression technique at the 2-week and 2-year follow-up visits. Restoration margins were evaluated under scanning electron microscopy, and marginal continuity was calculated as a percentage of the whole margin at the tooth-cement (TC) interface and the zirconia-cement (ZC) interface. RESULTS After a mean observation period of 26.2 months, all restorations were still in function. The only complication encountered was debonding of restorations; however, they were re-bonded back in place without issue. The cumulative Kaplan-Meier 2-year survival rate for the IRFDPs was 86.6%. There was a significant difference between the two groups regarding percentage of continuous margins (P < .05) after 2 years, with the percentage of continuous margins in the ID group at 92.8% and 91.5% at the TC and ZC interfaces, respectively, and in the PB group at 84.1% and 78.6% at the TC and ZC interfaces, respectively. CONCLUSION Zirconia-based monolithic IRFDPs can be recommended for short-term replacement of a single maxillary molar.

One of the chronic problems with traditional cement or screw retention of crowns to implants is the development of biologic and technical complications, including soft tissue complications, bone loss, screw loosening, loss of retention, and veneering material fractures. The purpose of this case series report is to document preliminary results, specifically crown retention, using a friction-fit connection of crown to abutment. A sample composed of patients who had one or more implants restored between July 1, 2019, and October 30, 2019, were enrolled in this retrospective case-control series. Each patient had their crown connected to the implant abutment using a friction-fit system. Patients were seen for routine follow-up for documentation of crown retention, and 24 crowns were followed. After 6 months of follow-up, 100% of the crowns retained retention and did not become loose under normal masticatory function. The use of a friction-fit connection provided excellent retention of the crown to the abutment over the 6-month follow-up period.

Aim To evaluate the prevalence of buccal peri-implant soft tissue dehiscence (PISTD) in anterior implants and to identify the risk/protective indicators of PISTD in implants not suffering peri-implantitis. Materials and methods 240 randomly selected patients from a university clinic database were invited to participate in the present cross-sectional study. Those who accepted, after the evaluation of their medical and dental records, were clinically examined to assess the prevalence of buccal PISTD in non-molar implants. Multilevel multivariate logistic regression analyses were then carried out to identify those factors associated either positively (risk) or negatively (protective) with buccal PISTD in implants without peri-implantitis. Results 92 patients with a total of 272 dental implants were analysed. At implant-level, the prevalence of buccal PISTD was 16.9%, while when selecting only implants without peri-implantitis it was 12.0%. Buccal PISTD was present in 26.7% of the implants diagnosed with peri-implantitis. The following factors were identified as risk/protective indicators of buccal PISTD in implants without peri-implantitis: malposition (too buccal vs. correct: OR=14.67), thin peri-implant phenotype (OR=8.31), presence of at least one adjacent tooth (OR=0.08) and presence of abutment (OR=0.12). Conclusions PISTD are highly prevalent among patients with dental implants in this university-based population, and several factors were identified as risk and protective indicators of PISTD in implants not suffering peri-implantitis.

Background Customized sealing socket abutment (SSA) has been claimed to optimize the peri-implant hard and soft tissues in type 1 implant placement. However, the evidence to claim the benefits of this technique over the use a conventional healing abutment remains weak. Purpose The aim of this retrospective study was to provide a 3D-radiographic evaluation of hard tissues changes following immediate implant placement in molar sites combined to ARP technique and installation of SSA. Materials and methods Baseline and follow-up (FU) CBCTs (from 1 to 5 years) of 26 patients were collected and included in the study. Baseline and FU CBCTs were superimposed and horizontal and vertical bone changes were assessed. Results A total of 26 patients and 27 implants were included. Horizontal bone remodeling was not significant in any of the measured areas except in the most cervical level, where a mean bone remodeling of 0.73 mm was found. Proximal and buccal vertical bone changes were not significant. Conclusions Within the limits of a retrospective study, dimensional alveolar ridge changes 1 to 5 years after immediate implant placement in molar sites with simultaneous ARP technique and installation of SSA seem to be very limited.

Purpose Implant component fractures are one of the most serious complications in implant treatment. With a better understanding of the risk factors for fracture in the preoperative, surgery, superstructure, and post-loading phases of implant treatment, low-risk treatment could reduce implant component fractures, leading to a better prognosis. The aim of this study was to clarify the risk factors for abutment and implant fractures that occur after loading, and to perform a retrospective, approximately 10-year follow-up study to explore the risk factors in each treatment phase. Methods Subjects were fitted with an implant prosthesis between January 2008 and December 2009. In total, 1,126 Ankylos implants in 430 patients were included for analysis. Binary logistic regression analysis was performed to extract factors related to non-fracture and fracture of the abutment or implant as a dependent variable. Results Gender (OR = 3.466, 95% CI 1.296-9.268, P = 0.013), gonial angle (OR = 3.420, 95% CI 1.308-8.945, P = 0.012), and splinting status of the superstructure (OR = 4.456, 95% CI 1.861-10.669, P = 0.001) were identified as significant risk factors. Conclusion The risk of fracture is increased in males, especially those with a mandibular angle of less than 120° on panoramic radiographs, and those with a non-splinted superstructure.

The prevalence of the elderly population increased in the 20th century, as described in the World Health Organization 2004 Annual Report. The use of tilted implants parallel to the anterior wall of the maxillary sinus or the mental foramen/inferior alveolar nerve has been proposed for the treatment of the atrophic edentulous ridge. The aim of this study was to evaluate stress and strain magnitude in tapered and cylindrical surrounding bones. A 3D finite element model of an edentulous mandible was constructed. Two models of implants were used: cylindrical and tapered BEGO Semados RI Implants. Four implants were inserted between the bilateral mental foramen according to All-on-Four concept, and a mandibular bar was designed to use with the All-on-Four bar supported models. A vertical and 30 degree vertical load of 100 N was applied to both cylindrical and tapered implants models. Strain and stress were analyzed with ANSYS software (ANSYS R18.0). The maximum stress and strain were applied in all axes for the posterior man-dibular areas in the crestal region of the bone, and for the anterior areas at the intraosseous contact site. Also, the stress and strain of the bone under force in all axes in all areas for tapered implants is less compared to that for cylindrical implants. We found that the highest rate of bone resorption occurs in the posterior areas near the junction of the fixture with the abutment of implant, and in the anterior areas near the end of the fixture of implant. Still, more research on the subject is needed.

Purpose Abutment screw loosening is a frequently encountered prosthetic complication in implant dentistry. Due to the detection of preload loss soon after initial torque application, abutment screw retightening 10 minutes after initial tightening has been recommended. The aim of this clinical study was to assess preload maintenance in the abutment screws of single posterior implants after 1 month of use by employing screw-cement-retained prostheses and a clinical assessing method, with the ultimate goal of helping to improve the clinical workflow of implant-based restorations. Materials and methods In total, 158 patients treated using three implant systems were divided randomly into two groups in which abutment screws were and were not retightened, respectively, approximately 10 minutes after initial torque application. Screw-cement-retained prostheses, which permitted the assessment of abutment screw preload maintenance and screw retightening after 1 month of use, were used. Preload loss at 1 month was defined as the failure to achieve the torque recommended for the abutment screws after 90-degree clockwise rotation of the screwdriver. The data were analyzed using binary logistic regression, with a significance level of P ≤ .05. Results No preload loss was detected 10 minutes after initial screw tightening. Preload loss was detected in 16 (10.13%) cases at 1 month after initial tightening, with no significant difference according to the implant system used, the presence or absence of retightening at 10 minutes after initial tightening, or implant position (premolar or molar). Conclusion Under the experimental conditions of this study, abutment screws in some bone-level, internal tapered-connection, platform-switching implant systems showed preload loss at 1 month after abutment placement for single posterior implant-based restorations, regardless of implant system or whether abutment screws had been retightened 10 minutes after abutment placement, or implant position (premolar or molar). It is necessary to retorque the abutment screws 1 month after initial torque. The screw-cement-retained prostheses used in this study permit abutment screw retightening at that time and have advantages over traditional methods.

Purpose To investigate the risk of debonding of resin-bonded fixed dental prosthesis frameworks and the effects on the periodontal tissue in patients with reduced alveolar bone levels. Materials & methods The abutment teeth were the upper central incisor and the canine. Resin-bonded fixed dental prosthesis framework fabricated using zirconia was set to models with five different alveolar bone levels. A 200-N load (the maximum clenching force of the anterior teeth) was applied to the center of the pontic to analyze the internal stress on the framework, adhesive cement, and periodontal tissue using finite element analysis. Results The mean maximum principal stress generated in the framework was 25.33 and 29.35 MPa in the models with the normal and the lowest alveolar bone level, respectively. Regarding shear stress on the adhesive cement, stress concentration was observed on the connector side in all models, and it increased on the cervical side of the central incisor as the alveolar bone level decreased. In addition, the mean maximum and minimum principal strains generated on the periodontal ligament of the central incisor and canine tended to increase as alveolar bone loss progressed. Furthermore, the mean maximum principal stress on the cortical bone was the greatest in the model with the most significant bone loss at 5.10 MPa. Conclusions This study suggested that the risk of debonding and periodontal tissue damage might be higher when resin-bonded fixed dental prosthesis frameworks were used in patients with reduced alveolar bone levels compared to those in a healthy state. This article is protected by copyright. All rights reserved.

BACKGROUND Peri-implant tissue condition can result from prosthodontic, surgical and bacteriological factors. PURPOSE This study investigated the effects of prosthodontic factors on peri-implant tissue. MATERIALS AND METHODS Subjects were 140 patients with 310 implants from Osaka University Dental Hospital. Prosthodontic factors examined were the connection type, the suprastructure retention type, the material of the abutment and the mesiodistal and buccolingual prosthetic form of the superstructure as emergence angle. The objective variables were the modified bleeding index (mBI) and marginal bone level (MBL). Statistical analysis was used as a generalized estimation equation. RESULTS The taper joint had a significantly smaller MBL than the butt joint (P

This retrospective clinical study was conducted to evaluate the clinical usefulness of a freely removable microlocking implant prosthesis (MLP) that was developed to overcome the problems with conventional implant prostheses. A total of 54 patients (male: 31, female: 23) and 100 implant prostheses were included. Patients were divided into three groups such as 6-12 months, 12-18 months, and 18-24 months according to the used period after implant prosthesis delivery, and the patients in each group were recalled for examinations of survival rate, marginal bone resorption, peri-implant soft tissue indices, and complications. The prosthetic complications were analysed by combining the recorded chart data during the periodic checks including the last call for this study. During a 2-year observation period, all the implants showed a 100% survival rate without clinical mobility and functional problems. There was no significant difference in marginal bone resorption, plaque index, and bleeding index over the observation period after implant prosthesis delivery. Probing depth of the 18-24 months group (1.5±0.19 mm) was significantly lower than that of the 6-12 months group (p<0.05). The main complication was abutment loosening (4%), followed by implant prosthesis fracture (2%) and food impaction (2%) which were recorded. Within the limits of the present study, the implant prostheses with MLP are considered to be an applicable and predictable treatment method.

Background: The purpose of this study was to report the results of metaphyseal and diaphyseal ulnar shortening osteotomies (USO) for the treatment of ulnar abutment syndrome (UAS). Methods: From 2011 to 2016, we performed metaphyseal USO in 8 patients (8 wrists) and diaphyseal USO in 6 patients (7 wrists). The results were investigated in terms of bone union and cast immobilization, wrist and forearm range of motion (ROM). The mean follow-up duration was 29 months. Results: All 14 patients had bone union. The mean duration of bone union in metaphyseal USO and diaphyseal USO were 3.5 months and 4.3 months and the duration of cast immobilization after surgery were 24.2 days and 29.2 days. The mean forearm ROM (degree) were 134.3 (pronation/supination: 66.7/67.6) and 169.3 (pronation/supination: 84.3/85.0) at 3 months after surgery and 173.4 (pronation/supination: 86.0/87.4) and 172.8 (pronation/supination: 87.1/85.7) at 6 months after surgery. Conclusions: The results from this study suggest that metaphyseal osteotomies are an effective alternative to diaphyseal osteotomies for the treatment of ulnar abutment syndrome. Although metaphyseal osteotomies were associated with temporary decrease of pronation, this discrepancy resolved at 6 months postoperatively. Metaphyseal USO has the potential to promote primary bone union and appears to be an alternative treatment for UAS.

This clinical report presents the use of a modified polyetheretherketone (PEEK) Inlay Retained Resin Bonded Fixed Dental Prosthesis (IRRBFDP) framework, veneered with indirect high impact composite for the bilateral restoration of mandibular first molar teeth, as the most conservative treatment option for a medically compromised patient. When used as a framework, PEEK's elastic modulus (approximately 4 GPa), could result in the reduction of stresses transferred to the abutment teeth and the cementation interface accordingly, therefore it could result in lower de-bonding rates and higher success rates. Furthermore, the high bond strength with the veneering composite material and the luting cements permit its use for resin-bonded restorations. Preparation guidelines, indications and advantages for the fabrication of IRRBFDPs are described in this clinical report. No technical complications such as de-bonding of the framework, connector or retainer fracture of the adhesive frameworks or loss of retention were observed during the course of 8 years. Prosthetic replacement of single missing posterior mandibular teeth utilizing IRRBFDPs with high performance polymer materials could potentially offer long-term high survival rate outcomes. Further clinical evidence is required in order to justify the above statement.

OBJECTIVES The aim of this study was to examine the microbial composition of early (after 3 days, D3) and mature biofilms (after 31 days, D31) on materials typically used in implant/abutment buildups. Implant/abutment materials with different surface roughness values (Ra ) were compared to detect differences in the quantity and quality of bacterial composition. MATERIAL AND METHODS Four different materials were investigated: rough implant surface (sand-blasted acid-etched titanium, Ti-p), implant collar (machined titanium, Ti-m), titanium abutment (Ti6Al4V), and zirconium dioxide abutment (ZrO2 ). Fourteen periodontally healthy subjects received mandibular acrylic devices with four disks (one for each material) facing the anterior lingual area. The total bacterial count was analyzed using RT-qPCR. Both presence and proliferation of 20 selected bacterial species were assessed with microarrays. RESULTS The highest mean total cell counts (x108 ± standard deviation) were detected at D3 on ZrO2 (5.63 ± 4.83; Ra = 0.74 µm), followed by Ti-p (4.53 ± 5.00; Ra = 1.87), Ti-m (4.43 ± 9.38; Ra = 0.18 µm), and Ti6Al4V (3.83 ± 3.13; Ra = 0.16 µm). ZrO2 showed significantly higher total bacterial cell counts than Ti-p and Ti-m (p

Purpose To evaluate the clinical performance and survival rate of posterior monolithic zirconia fixed partial dentures over a 2-year period. Material and methods A total of 20 patients, requiring 20 posterior fixed partial dentures were included in the study. Tooth preparations were scanned, and restorations were milled and cemented with a resin cement. The restorations were assessed for the quality of the surface and the color, anatomical form and marginal integrity. Periodontal status was assessed by determining the plaque index, gingival index, pocket depth, and margin index of the abutment teeth. Data were statistically analyzed using the Friedman and the Wilcoxon signed-rank tests with the Bonferroni correction. Results The survival rate at 2 years was 100%, and no biological or technical complications were observed. All restorations were assessed as satisfactory. The results obtained for gingival index and plaque index were better at 2 years follow-up, than at baseline. The margin index remained stable throughout the follow-up period. No differences in periodontal parameters were observed between abutment and control teeth. Conclusions The high survival rate after 2 years suggest that monolithic zirconia may be an acceptable alternative to metal-ceramic and veneered zirconia restorations in the posterior region. Additional long-term, controlled studies are necessary to confirm the results.

Statement of problem Resin-bonded fixed partial dentures (RBFPDs) are a reliable treatment option for the replacement of a single missing tooth. Glass-ceramic may be a promising material for the fabrication of RBFPDs, but clinical verification has been lacking. Purpose The purpose of this prospective clinical study was to evaluate the outcomes of glass-ceramic RBFPDs on participants with a single missing premolar. Material and methods Twenty participants (6 men, 14 women; age range: 20 to 54 years) were treated with 2-retainer RBFPDs. These RBFPDs were made of lithium disilicate glass-ceramic (IPS e.max Press; Ivoclar Vivadent AG) and designed with improved C-shaped retention. These prostheses were evaluated at 6 months, 12 months, and annually thereafter and were classified as survival or failure. Analysis was performed with the Kaplan-Meier analysis (95% confidence interval). Modified United States Public Health Service (USPHS) criteria were used to rate the clinical performance. Parameters assessed were fracture, marginal integrity, marginal discoloration, color of restoration, secondary caries, and abutment mobility. Results Twenty RBFPDs were provided, 9 in the maxilla and 11 in the mandible. The mean observation time was 49.2 months (minimum 9 months, maximum 53 months). Nineteen RBFPDs were evaluated as having survived during the observation period with some acceptable marginal discoloration, 1 RBFPD had to be replaced because of fracture and secondary caries and was evaluated as a failure. The Kaplan-Meier analysis revealed a survival rate of 95% after a 4-year observation. Conclusions The glass-ceramic RBFPDs in this study displayed a good survival rate and clinical performance, indicating that glass-ceramic RBFPDs might be a promising approach for the short-term replacement of a single premolar. However, further investigations are needed to determine the long-term outcome.

Purpose To evaluate the implant and prosthetic outcomes and biologic and technical complications of tooth-implant- supported fixed dental prostheses (TISFDPs) in comparison with implant-supported fixed dental prostheses (ISFDPs). Materials and methods A comprehensive electronic search was performed by two independent reviewers up to February 2019. A hand search in relevant dental journals was also performed. The search identified a total of 175 citations, and 160 were excluded. Of the remaining 15 articles, seven were included in the review. Results The implant failure rate was between 0% and 9% for the TISFDPs and between 0% and 13% for the ISFDPs, and the prosthesis failure rate was between 0% and 13% for the TISFDPs and between 0% and 17% for the ISFDPs; no significant differences were observed within 24 to 120 months of follow-up. Less peri-implant marginal bone loss was observed in the TISFDPs (MD: -0.29; 95% CI: -0.58, 0.00; P = .05), but the difference was marginally significant. Abutment tooth intrusion rate was 3%, while abutment tooth fracture rate was between 0% and 4%. No significant differences in the technical complications were observed, although the TISFDPs had higher failure rates in framework fracture and abutment/prosthesis screw loosening, while ISFDPs had a higher failure rate in porcelain fracture. Conclusion The TISFDPs could be an alternative treatment option to ISFDPs for the partially edentulous patient with both treatments achieving comparable implant, prosthetic, biologic, and technical outcomes.

Objectives This study aimed to survey dentists in Germany to identify their favored materials for the fabrication of tooth-supported single crowns (SCs) depending on the location of the abutment teeth and the preparation margin. Materials and methods The survey included questions regarding demographic characteristics of dentists/their dental practice and preferred restorative materials for the fabrication of SCs for abutment teeth 16, 11, 34, and 36 with either supra- or subgingival preparation margins. Results Between August 2019 and February 2020, 721 dentists participated in the survey; responses from 33 dentists were excluded from data analysis because the dentists did not work in Germany or provided less than one fixed dental prosthesis/month. Dentists favored ceramic materials independent of the location of the abutment tooth and preparation margin (56.6–92.2%). CAD/CAM resin composites or full metals were preferred by only a few participants. A significantly higher proportion of dentists recommended porcelain fused to metal for subgingival preparation margins than for supragingival margins (p Conclusions Dentists in Germany selected restorative materials for SCs depending on the clinical scenario. Since numerous dentists did not specify the ceramic materials, postgraduate information and education might help to extend expertise. Clinical relevance The results of this survey provide insight into the favored materials of dentists for the fabrication of tooth-supported SCs.

Introduction The rehabilitation of a maxillary single dental implant represents a great challenge at clinical practice. Harmony among the implant-supported crown and adjacent teeth is required in which concerns pink and white esthetics. The aim of the present case report is to depict a multidisciplinary treatment in which the U-shape flap technique for papillae preservation at second stage surgery was used. Case presentation One female patient presenting an un-rehabilitated dental implant at the left central incisor position sought treatment at the Centre of Education and Research on Dental Implants (CEPID). Alterations of color, shape, and position were observed on the anterior maxillary teeth. For proper treatment planning, radiograph, wax-up, and mock-up were performed. Second stage surgery was performed by the U-shape flap technique. A trunnion abutment was installed at the implant and a provisional subcontoured cemented crown was manufactured. Dental bleaching, feldspathic veneers, and a ceramic crown were performed. Oral hygiene instructions were recommended. Follow-up appointments were set at 1.5 and 3 years after restoration placement. After 3-year follow-up, soft tissue stability and health were preserved and papillae coronal migration around the single dental implant was observed. A complication-free treatment was reached, and patient demonstrated satisfaction towards esthetic and function. Conclusions The use of U-shape technique at second stage surgery associated to adequate prosthetic contour improved soft tissue esthetic outcomes, while the multidisciplinary treatment planning provided adequate solutions, refining harmony between dental and implant-supported components.

Introduction Dental trauma and congenital anodontia are common causes of anodontia in the anterior maxilla. The proposed restorative treatment constitutes a challenge for many dentists, particularly if it is a question of a young patient who has not yet completed skeletal and dental development. Current treatments for anterior maxillary anodontia include: fixed or removable partial dentures; orthodontic closure of interdental spaces; and dental implants. Dental implants do not move with the dento-alveolar complex during the growth period of the maxilla. Therefore, many researchers maintain that implants should be postponed until after adolescence, in order to prevent complications, such as infra-occlusion, that would require the replacement of the abutment and crown-implant restoration, or even invasive treatments, such as the removal of the implant in the future. The objective of this literature review is to investigate the aetiology of the phenomenon, and outcome. Results Continuous tooth eruption is not affected by age, so considerable changes may occur due to eruption of adjacent teeth. In addition, both women and men are affected by this phenomenon and, usually, there is no significant difference in the amount of growth between the short face and the long face. Conclusion It can be concluded that continuous facial skeletal growth and teeth eruption are evident in the second and third decades. Where possible, it is advisable to delay placement of an anterior maxillary implant in the adolescent patient.

Alveolar bone atrophy can directly cause a decrease in bone level. The effect of this process on the service life of dental implants is unknown. The aim of this study was to determine the failure forms of the two-piece dental implants in the descending process of alveolar bone level, and the specific states of the components during the failure process. The CAD software SolidWorks was used to establish the model of alveolar bone and dental implants in this article. The finite element analysis was used to analyze the statics of the dental implants in the host oral model. The finite element analysis results showed that the stress concentration point of the implant and abutment in the implant system has changed greatly during the descending process of alveolar bone level, and indirectly increased the fatigue life of the same fatigue risk point. At the same time, the dental implants were tested in vitro in the descending process of alveolar bone level. Then, the fracture of the implant system was scanned by scanning electron microscope. The fatigue test results proved the finite element analysis hypothesis the central screw first fractured under fatigue and then caused an overload break of the implant and abutment.

Background Low-level laser therapy (LLLT) has been suggested to improve primary stability at the early stages of osseointegration in animal models. However, there is still scarce evidence about its influence on implant stability in humans. Purpose To assess the influence of LLLT on implant stability in implants placed in fresh extraction sockets. Material and methods A randomized controlled trial was designed according to the SPIRIT guidelines and is reported following the CONSORT. Patients were randomly allocated according to control or LLLT groups. LLLT consisted in the application of GaAlAs laser (808 nm, avg. power density: 50 mW, circular spot diameter and area: 0.71 cm/0.4cm2 ) applied in six points in contact mode with peri-implant soft tissue (1.23 minutes in each point of application; dose per point 11 J) before bone perforation and after suturing. The total dose resulted in 66 J per application moment. This LLLT protocol was applied only in the dental implant placement session. Implant stability was by ISQ at implant placement (T0 ) and the abutment selection (Ta ). Digital radiographs for T0 and Ta were used to assess the distance between the implant platform and alveolar bone crest, in millimeters. T-test and Shapiro-Wilk test were used to analyze data between groups using the implant as a unit of analysis. Results Fifty implants were placed in 44 patients. The insertion torque ranged from 15 to 60 N.cm (mean 35.64 ± 13.34). Two implants of the LLLT and one of the control groups were lost to follow-up and one implant of the control group failed to osseointegrate (4.3%). ISQ at T0 ranged from 17 to 79 (mean 59.33 ± 13.05) and from 40 to 89 (mean 66.46 SD ± 11.56) at Ta . No differences were observed when comparing the groups with ISQ difference (P = .433) or radiographical peri-implant alterations (P = .261). Conclusions LLLT did not influence implant stability in implants placed in fresh extraction sockets when assessed at healing abutment installation.

We aimed to investigate a possible relationship between early implant failure (EIF) and an adjacent root canal–treated tooth and/or tooth with a periapical lesion (PL), considering the duration between implantation and root canal treatment (RCT). The importance of prior RCT and/or presence of a PL before implantation was also investigated. A total of 810 implants from 342 patients were included and scored according to the implant failure before abutment connection, adjacent root canal treated teeth, adjacent teeth without RCT, no adjacent teeth, adjacent teeth with PL, extraction of teeth with PL, and/or RCT before implantation. The durations between the extraction and implantation and between RCT and implantation adjacent to the root canal–treated teeth were recorded. The time from the RCT of adjacent teeth to implant placement was categorized into 5 groups: less than 4 weeks before implantation, 4–12 weeks before implantation, at least 12 weeks before implantation, within 4 weeks after implantation, and at least 4 weeks after implantation. Among the endodontic predictors, a prior PL on the tooth extracted was associated with an increased risk of EIF (P < .05, odds ratio: 4.37; 95% confidence interval: 1.604–11.891). Furthermore, EIF was more likely to occur when the RCT of an adjacent tooth was performed within 4 weeks of implantation (P < .05). Additional investigations with larger sample sizes are necessary to validate our findings.

Background Implant-supported fixed partial dentures (ISFPDs) are one of the most common options to rehabilitate partially edentulous patients. Purpose To assess the clinical outcomes of ISFPDs. Methods This retrospective study included all patients treated with ISFPDs with 2 to 6 prosthetic units at one specialist clinic. Implant/prosthesis failure and technical complications were the outcomes analyzed. Results Six hundred and forty-two patients with 876 ISFPDs (2241 implants) were included, followed up for 108.0 ± 76.2 months. Eighty-eight prostheses and 112 implants (26 before, 86 after prosthesis installation) failed. The estimated CSR of ISFPDs at 30 years was 72.7%. Smokers presented lower implant survival than nonsmokers. Two hundred and ninety-nine ISFPDs (33.2%) presented technical complications. Bruxism was a factor to exert a higher risk of screw and implant fracture, and ceramic chipping. ISFPDs with cantilever presented higher risk of failure, and screw loosening/fracture. Prostheses supported by implants with internal abutment connection or with two pontics had higher risk of presenting ceramic chipping. Extension of the prosthesis did not seem to exert influence on prosthesis failure/complications. Conclusions ISFPDs presented good long-term prognosis. Implant failure was the main reason for ISFPD failure. The results suggest that bruxism and the presence of cantilever may contribute to the increased rate of mechanical complications and prosthesis failure.

Ulnar abutment (ulnocarpal impaction) syndrome may be a source of ulnar-sided wrist pain in the athlete. This condition results from excessive load transfer across the triangular fibrocartilage complex and ulnocarpal joints with characteristic degenerative changes. It frequently occurs in patients with either static or dynamic ulnar positive variance. Treatment is tailored to the athlete and their sporting demands. Surgical treatment focuses on addressing ulnar variance to unload the ulnocarpal joint, with multiple surgical options, including the metaphyseal closing wedge osteotomy achieving this goal. This review focuses on the presentation, biomechanics, and treatment options for ulnar abutment syndrome in the athlete.

Objectives To prospectively evaluate, as part of an ongoing randomized pilot trial, the clinical outcomes of two-piece zirconia implants in comparison with titanium implants 80 months after delivery of all-ceramic (lithium disilicate) single-tooth restorations. Material and methods The original sample included 31 (16 zirconia and 15 titanium) implants in 22 healthy patients. In addition to evaluating implant survival and success, a number of clinical or radiographic parameters were statistically analyzed: plaque index (PI), bleeding on probing (BOP), pink esthetic score (PES), and marginal bone loss (MBL). Both implant groups were compared using a Mann-Whitney U test. Results Three implants (2 zirconia and 1 titanium) had been lost, so that 28 implants (14 zirconia and 14 titanium) in 21 patients could be evaluated after a mean of 80.9 (SD: 5.5) months. All surviving implants had remained stable, in the absence of any fixture or abutment fractures and without any chipping, fracture, or debonding of crowns. The zirconia implants were associated with PI values of 11.07% (SD: 8.11) and the titanium implants with 15.20% (SD: 15.58), the respective figures for the other parameters being 16.43% (SD: 6.16) or 12.60% (SD: 7.66) for BOP; 11.11 (SD: 1.27) or 11.56 (SD: 1.01) for PES; and 1.38 mm (SD: 0.81) or 1.17 mm (SD: 0.73) for MBL. Conclusions No significant differences were found between the clinical outcomes of two-piece zirconia and titanium implants based on the aforementioned parameters after 80 months of clinical service. Our results should be interpreted with the limited sample size in mind.

The purpose of this study was to clinically investigate double-crown-retained removable partial dentures (DRPDs) and abutment teeth at dental clinics. Only cases with complete arch reconstruction were included. Endpoints were replacement of denture and loss of abutment tooth. A total of 213 dentures with 1030 abutment teeth were analyzed. During the observation period, 32 dentures were replaced. The mean observation period was 12.7 (± 6.6) years (range 3 to 36). By the Kaplan-Meier method, survival rate at 10 years was 94.7% and at 20 years was 70.8%. Estimated mean survival period was 27.1 years. Cox regression analysis showed that risk factor for replacement was good occlusion as indicated by Eichner index groups A to B3 (HR 2.81). The main reason for denture replacement was loss of abutment teeth. Survival rate of abutment teeth at 10 years was 83.8% and at 20 years was 66.3%. The analysis revealed six risk factors: male gender (HR 1.76), age range 65–89 years (HR 1.51), posterior teeth (HR 1.60), higher number of present teeth in opposite jaw (HR 1.69), lower number of abutment teeth (HR 1.76), and short inner crown (HR 2.28). DRPDs last over 20 years, making them a durable investment in one’s oral health; their survival is influenced by loss of abutment teeth. In cases where there are few teeth remaining in a jaw, DRPDs represent a suitable treatment that makes use of the remaining teeth, even if the abutment teeth are non-vital.

This case report aimed to describe a soft tissue approach to restore a buccal soft tissue dehiscence (BSTD) combined with the loss of peri-implant papillae and loss of periodontal attachment on the adjacent teeth. The first step of the proposed approach was the removal of the crown and abutment to leave the interproximal soft tissue to fill the space previously occupied by the crown. After 3 months, during which time the patient was wearing a provisional restoration (a temporary Maryland bridge), the implant site was treated as an edentulous area with a soft tissue augmentation procedure: the most substantial modification with respect to the original connective tissue platform technique was the use of the wide mesial and distal papillae of the implant, once de-epithelialized on the occlusal surface, as a "partial" connective platform to suture the connective grafts and submerge the implant. At the 4-month reevaluation visit, a minor soft tissue defect remained in both apico-coronal and buccolingual dimensions, and thus a second surgery was performed to obtain further soft tissue augmentation. A flapless punch procedure was used to expose the implant head, and after conditioning the augmented peri-implant soft tissue with a new provisional crown, the definitive restoration was delivered. Complete coverage of the BSTD was achieved, and both papillae entirely filled the interproximal spaces. The results were well maintained up to the 5-year follow-up visit.

Purpose To evaluate the survival rates of dental implants that had been reimplanted in sites of previous failure, including first, second, and third reimplantations, and investigate the various factors that could affect the reimplantation outcomes. Materials and methods All dental implants placed in sites of previous implant failure were identified, including first, second, and third reimplantations. The survival rates were assessed, and epidemiologic and clinical data were collected and analyzed to evaluate the effects on reimplantation survival. Results The survival rate for the total number of initial implants placed was 95.4% (5280 of 5532). For the 208 patients with failed implants, the survival rate was 62.0% (412 of 664). The survival rate of the implants placed in the sites of previous failure (first reimplantation) was 77.4% (137 of 177 implants). A statistically significant difference was found (P = .0001) between the survival rates of implants placed for the first time and implants placed into sites of previous failure. The survival rate of the second reimplantations was 72.7% (16 of 22). The survival rate of the third reimplantations was 50.0% (1 of 2). Each implant and reimplant group demonstrated a statistically significant greater percentage of postoperative pain reports in the failure group than in the survival group. A significantly greater percentage of early failures (failures occurring before abutment connection) occurred compared with late failures for each implant and reimplant group. Conclusions Dental implants placed in sites of previous implant failure had lower survival rates than those of the initial implants, and our findings suggested that the survival rates will be consecutively lower with each successive reimplantation at the same site. Implant and reimplant failures were associated with higher rates of postoperative pain reports and were more often early failures. Such suggestions could improve clinicians' prediction for implant failure and allow for optimization of the conditions to improve implant survival.

Aim: To test whether or not buccal vertical bone dehiscences (≤5 mm) around posterior implants left for spontaneous healing (SH) result in the same clinical and radiologic outcome as dehiscences treated with guided bone regeneration (GBR) at 7.5 years after implant placement (IMPL). Materials and methods: Twenty-two patients receiving 28 posterior implants with a small non-contained buccal bone dehiscence (≤5 mm) were randomly assigned to the SH or the GBR group. Implants were loaded at 6 months. Clinical parameters (probing depths, sulcus bleeding index, plaque index) and approximal marginal radiographic bone levels were assessed regularly up to at least 6.8 years. The vertical extension of the dehiscences was measured clinically at IMPL and abutment connection and radiographically on cone beam computed tomographys at a mean follow-up time of 7.5 years. Results: Twenty patients with a total of 26 implants were recalled at 7.5 years (9.1% dropout). The implant/crown survival rates were 100% in both groups. Stable peri-implant tissues were observed in both groups showing only minimal signs of inflammation. During the entire study period (IMPL-7.5-year follow-up), the median buccal vertical bone gain measured 1.61 mm for the GBR group and 0.62 for the SH group showing no significant difference between the groups. Also, at 7.5 years, the median approximal marginal bone levels (GBR: 0.53; SH: 0.68) were not significantly different between the two groups (p = .61) while the remaining median buccal vertical dehiscences were larger in the SH group (2.51 mm) compared to the GBR group (1.66 mm; p = .02). Conclusions: Implants with small non-contained buccal bone dehiscences exhibited high implant survival rates and healthy peri-implant tissues at 7.5 years. In the GBR group, the buccal vertical bone levels were higher compared to the SH group but remained stable over the entire study period for both treatments. Keywords: bone substitute; dental implant; guided bone regeneration; small buccal defects; spontaneous healing. © 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Background: Postoperative results of ulnar shortening osteotomy for ulnar abutment syndrome were compared between groups of patients in whom the plate was placed on the volar side and those in whom the plate was placed on the dorsal side.Methods: A total of 35 wrists of 14 males and 21 females were evaluated. The average age of patients at surgery was 44.3 years, and the average follow-up period was 66.2 months. After transverse osteotomy was performed, the ulna was fixed using a 6-hole LC-LCP or a LC-DCP on the dorsal (group D) or the volar (group V) side, respectively. Imaging and clinical results, rates and reasons for implant removal were evaluated.Results: There were 27 patients in group D and 8 in group V. A significant difference was observed only in the postoperative grip strength compared with that of the unaffected side between groups V and D (102% and 87%, respectively). Implant removal was performed in 18 (64%) patients in group D and in 7 (88%) in group V, and the main reasons for this were pain in group V and discomfort in group D. Re-fracture occurred after implant removal in one patient in group D.Conclusions: There were no differences in the imaging and clinical results depending on the plate position. It is preferable to avoid implant removal by placing the lower profile plate on the dorsal side.

Digital surgical planning for immediately loaded dental implants can be a predictable and accurate procedure, with the interim prosthesis also designed digitally. If the planning and execution are meticulous, chairside adjustments can be minimized because the outcome should be closely matched to the proposed digital plan. A novel dental implant abutment system made from a shape memory metal could be an answer to the cement versus screw controversy as it uses neither. This new system can provide patients with better esthetics and is biologically favorable.

BACKGROUND Bone anchored hearing implants (BAHI) are widely used and highly successful, accompanied with a high level of patient satisfaction across most techniques. A large UK teaching hospital switched from the previously used wide diameter titanium fixture and drilling system to the novel minimally invasive technique and laser ablated titanium implant. Before this change the rates of fixture failure and skin problems necessitating abutment change were 1% each. METHODS Retrospective case note review of consecutive BAHI patients drawn from an electronic database between January 2015 and October 2016. RESULTS Data from a total of 118 procedures were reviewed, with different combinations of surgical techniques and implant types. Sixty procedures were performed via the novel minimally invasive technique with 21 failures (35%). Fourty-eight modified minimally invasive technique procedures were performed with seven failures. In 64 of the procedures, laser ablated titanium fixtures were placed with 21 failures (32.8%). In 54 procedures wide diameter titanium fixtures were placed with eight failures (5%). CONCLUSION Initial experience with the novel minimally invasive technique and laser ablated titanium fixture showed significantly higher failure rates than expected. This prompted a change to an open technique and subsequent abandonment of the laser ablated titanium fixture and custom drilling solution in our institution.

PATIENT This clinical report describes treatment with a double-crown-retained removable dental prosthesis fabricated using an intraoral scanner (IOS) and computer-aided design/manufacturing technology (CAD/CAM). A 68-year-old female patient presented with complaints of missing maxillary right first and left second premolars. CAD/CAM technology was applied to plan treatment with a double-crown-retained removable dental prosthesis. The patient consented to this treatment option but did not want orthodontic treatment for the anterior crossbite of the right side. After the definitive preparation of the abutment teeth, the shape of the provisional restoration was adjusted to match the definitive prosthesis. An IOS was used to obtain digital scans of the provisional restoration, occlusion, antagonist arch, and prepared surface of the abutment teeth. First, the primary crowns were milled from cobalt-chromium alloy. Next, using an intraoral scanner, a pickup impression of the primary crowns was performed, and the secondary crowns were designed, milled, and veneered. After delivery, the patient expressed satisfaction with the functionality, esthetics, and fit of the double-crown-retained removable dental prosthesis. DISCUSSION The surface of the primary crowns was coated with scan spray when the pick-up impression was made using the IOS. Practice is needed to achieve a thin and homogeneous coating with scan spray to improve reproducibility. CONCLUSION Double-crown-retained removable dental prostheses can be successfully fabricated using an IOS and CAD/CAM technology, resulting in patient satisfaction.

Purpose The purpose of this study was to investigate the inhibitory effect of night denture (ND) placement on abutment tooth mobility in removable partial denture (RPD) wearers with sleep bruxism (SB). Methods The participants were selected from RPD wearers diagnosed with SB using BiteStrip® and randomly allocated to one of the following groups: with ND placement or without ND placement (intervention or control group, respectively). The mobility of the RPD abutment tooth was measured using Periotest® at baseline (T0) and at 1 (T1), 3 (T3), and 6 months (T6). BiteStrip® scores were recorded at T0 and T6. Intragroup comparisons of the Periotest® value (PTV) were performed using analysis of covariance. Intergroup comparisons of PTV and BiteStrip® scores were performed using the linear mixed model and Wilcoxon signed-rank test, respectively. Intragroup comparisons of BiteStrip® scores were performed using the Mann-Whitney U test. Results At T6, the PTV in the intervention group was significantly lower than that in the control group (p=0.004). PTV was significantly lower at T6 than that at T0 in the intervention group (p=0.030), while PTV was significantly higher at T6 than that at T0 in the control group (p=0.007). There was no significant difference in the BiteStrip® score between the two groups. The BiteStrip® score at T6 was significantly lower than that at T0 only in the intervention group (p=0.011). Conclusion ND placement might inhibit the increase in mobility of RPD abutment teeth and be effective in protecting them in RPD wearers with SB.

The purpose of this study was to investigate the survival of removable partial dentures with a mandibular bilateral free end saddle (BFES) and abutment teeth in a clinical setting. Only mandibular dentures with a BFES were included (10 or fewer present teeth, and fewer than 4 occlusal units). The endpoints were replacement of denture and loss of abutment teeth. A total of 128 dentures and 595 abutment teeth were analyzed. Nineteen dentures had to be replaced during the observation period (mean duration: 11.4±6.9 years; range: 3 to 36 years). According to Kaplan-Meier analysis, the survival rate was 93.2% at 10 years and 68.6% at 20 years. The estimated mean survival period was 27.8 years. Single-factor analysis using the log-rank test showed that no factor investigated had a significant influence. The main reason for denture replacement was loss of abutment teeth (47.4%). The survival rate of the abutment teeth was 91.3% at 10 years and 77.3% at 20 years. The analysis revealed 4 significant risk factors: male sex (hazard ratio [HR]: 1.78); premolars (HR: 1.67); a lower number of abutment teeth (HR: 3.24); and history of endodontic treatment (HR: 2.79). The removable partial dentures with a mandibular BFES in this study lasted over 20 years, and their survival was influenced by loss of abutment teeth. Dentures are used continuously over long periods of time and should therefore be designed to allow easy adjustment when abutment teeth are lost.

BACKGROUND Esthetic complications of dental implants in the esthetic zone can have a major negative impact on patients' quality of life and perception of implant therapy. The aim of the present study was to evaluate the prevalence of peri-implant soft tissue dehiscence (PSTD) and the clinical and ultrasonographic risk indicators for this condition. METHODS Subjects with one or more healthy single dental implants in the esthetic area were identified and recruited. Clinical and ultrasonographic measurements, including PSTD class and subclass, pocket depth, keratinized mucosa width (KMW), mucosal thickness (MT) at 1 mm and 3 mm, buccal bone distance (BBD) and buccal bone thickness, were evaluated in healthy implants and implants with PSTD. RESULTS 153 subjects with a total of 176 dental implants were included. The prevalence of PSTD was 54.2% and 56.8% on a patient and implant level, respectively. The most frequent type of PSTD was the one characterized by having both an implant-supported crown longer than the clinical crown of the homologous tooth and a visible abutment/implant fixture exposed to the oral cavity. The multi-variate analysis showed that the presence of an adjacent implant, a longer time of the implant in function, limited MT, reduced KMW and increased BBD were significantly associated with the presence of a PSTD. CONCLUSIONS PSTDs are common findings in the esthetic region. Several risk indicators for this condition, such as presence of an adjacent implant, increased time in function of the implant, higher BBD, lower KMW and MT were identified. This article is protected by copyright. All rights reserved.

BackgroundRestoration with locking-taper implants is a widely used methodology. However, conical connection systems such as locking-taper implant systems have rarely been examined. This study provides a retrospective investigation of locking-taper fixed restorations, mainly focusing on prosthetic complications.MethodsPatients undergo treatment with conical connected implants from 2008 to 2010 were examined. Preparation of the implant sites was performed according to the standard procedures for the Bicon system. Bone healing took over 6 months, and the prosthetic procedure was initiated thereafter. Integrated abutment crowns or gold porcelain crowns were used, and the prosthesis type was a single crown or a fixed dental prosthesis. Once the crown was in place, its occlusion was thoroughly checked and adjusted, and then the crown was glazed or finely polished. The Kaplan–Meier method was used to calculate the cumulative complication-free rates for 5 and 10 years. Additionally, a Cox regression model was used to identify the factors that independently influenced the results. Implant survival and marginal bone loss were also investigated.ResultsA total of 392 patients who underwent 541 implants and 434 locking taper implant-based restorations from 2008 to 2010 were examined. The overall 5-year cumulative complication-free rate was 83.34%. The most common prosthetic complication was veneer chipping, with a frequency of 67.53%. According to the Cox regression model, the complication-free rate of integrated abutment crowns was significantly higher than that of gold porcelain crowns, that of molar regions was significantly higher than that of premolar regions, and that of females was significantly higher than that of males. Only three implant failures happened, and the mean marginal bone loss values at 1- year, 5-years and 10- years were 0.25 mm (95% CI ± 0.12), 0.40 mm (95% CI ± 0.03) and 0.51 mm (95% CI ± 0.05), respectively.ConclusionVeneer chipping was the most common complication with locking-taper implant-supported fixed restorations. The incidence of complications for IACs is significantly higher than that for GPCs. Age, location, and prosthesis type are not determinants of prosthetic complications. Besides, the long-term clinical effect of locking-taper implant can meet the clinical needs. The bone tissue level around the implant can maintain long-term stability.

Objectives This clinical study evaluated the outcome and survival rate of resin-bonded fixed dental prostheses (RBFDPs) made of 3Y-TZP zirconia ceramic with a single-retainer design in the replacement of missing canines, premolars and molars. Methods Twenty-one patients that were provided with twenty-seven cantilevered zirconia ceramic RBFDPs replacing maxillary or mandibular missing canines or posterior teeth were recruited from the patients’ database at the University of Kiel, Germany. The preparation of the abutment teeth was minimal and limited to the enamel and consisted of a retainer wing and an occlusal rest on the abutment tooth. The restorations were observed over up to 12 years. Results The patient age ranged from 16 to 72 years old with a mean age of 34 ± 21 years and 57% were females and 43% were males. The restorations were observed for a mean period of 53 ± 39 months with a minimum of 13 months and a maximum of 151 months of observation. No debonding for any of the restorations was detected, which amounts up to a survival rate of 100%. The development of treatable cervical caries on one abutment tooth of an elderly patient without extending to the retainer wing was the only recorded complication. Conclusions Zirconia ceramic single-retainer RBFDPs provide an esthetic, functional and minimally invasive treatment alternative to replace missing canines, premolar and molars with promising results due to excellent clinical outcome resulting from a survival rate of 100% and a success rate of 96.3% over a mean observation time of 53 ± 39 months. Clinical significance Zirconia ceramic single-retainer RBFDPs might be a valid minimally-invasive option for replacing missing canines and missing teeth in the posterior area especially for young patients, in whom implants are contraindicated and conventional fixed dental prostheses are too invasive.