Microleakage and Marginal Integrity of Ormocer/Methacrylate-Based Bulk-Fill Resin Restorations in MOD Cavities: SEM and Stereomicroscopic Evaluation.

This in vitro study aimed to compare the microleakage and marginal integrity of methacrylate/ormocer-based bulk-fill composite (BFC) restorations used in cervical marginal relocation with two different layering thicknesses in mesio-occlusal-distal (MOD) cavities exposed to thermo-mechanical loading. Standard MOD cavities were prepared in 60 mandibular molars and assigned into three groups: x-tra fil/AF + x-tra base/XB, Tetric N-Ceram Bulk Fill/TNB + Tetric N-Flow Bulk Fill/TFB, and Admira Fusion x-tra/AFX + Admira Fusion x-base/AFB. Each group was further divided into two subgroups (2 mm and 4 mm) based on the thickness of flowable BFCs (n = 10). The specimens were subjected to thermo-mechanical loading (240,000 cycles) and immersed in 0.2% methylene blue. Following mesiodistal sectioning, the specimens were examined under stereomicroscope (×25) and scored (0-3) for microleakage. Marginal integrity was examined using a scanning electron microscope (SEM). Descriptive statistical methods and the chi-square test were used to evaluate the data (p < 0.05). While there was no statistically significant difference in gingival cement microleakage in the XB and AFB specimens with a 4 mm thickness, microleakage was significantly increased in the TFB specimen (p = 0.604, 0.481, 0.018 respectively). A significantly higher amount of score 0 coronal microleakage was detected in the AFX2 mm + AFB4 mm compared to the TNB2 mm + TFB4 mm (p = 0.039). The SEM examination demonstrated better marginal integrity in groups with 2 mm thick flowable BFCs. Ormocer and methacrylate-based materials can be used in marginal relocation with thin layers.

Evaluating the Effect of Ambient and Scanning Lights on the Trueness of the Intraoral Scanner.

PURPOSE: To determine the influence of different scanning and ambient light conditions on the trueness values of an intraoral scanning (IOS) device. MATERIAL AND METHODS: The present study was conducted among 20 complete dentate volunteers. After making complete maxillary arch impressions with vinyl polysiloxane material, type IV dental stone was poured, and working casts were obtained. Then, the models were digitized using a dental laboratory scanner (LS) and standard tessellation language (STL) files were acquired. Full arch digital scans of the volunteers were also performed using an IOS device with 2 ambient light conditions (RL: room light, 1003 lux, and ZL: zero light, 0 lux) and 2 scanning light modes (blue [B] and white [W]). Twenty digital scans per group at each light condition were consecutively obtained. Discrepancy between the digital scans and digitized working casts was analyzed using a 3D inspection software. The obtained data were analyzed using one-way ANOVA and Tukey tests (α = 0.05). RESULTS: Significant differences were obtained among different light conditions for the IOS device (p ˂ 0.0001, F = 42.958 for positive deviations and F = 29.278, for negative deviations). The room light and blue mode (RLB) condition had the lowest deviation values compared with the other light conditions, followed by room light and white mode (RLW), zero light and blue mode (ZLB), and zero light and white mode (ZLW; p =  0.008, p Ë‚ 0.0001, and p Ë‚ 0.0001, respectively). CONCLUSION: Lighting conditions are effective in assessing the trueness of the digital impressions made with an IOS device. RLB conditions are recommended for taking a digital impression.

The Clinical and Radiologic Outcomes of Early Loaded Implants After 5 Years of Service.

PURPOSE: To evaluate the 5-year results of the clinical and radiographic outcomes of three types of early loaded implants. MATERIALS AND METHODS: Seventy-five implants were placed in the posterior mandible or maxilla in 30 patients. Three types of implants (Straumann SLActive, Astra OsseoSpeed, and Thommen Implant System) were used. Definitive restorations were made after 8 weeks of implant placement. The radiographs were taken at the placement of the prosthesis, at 6 months, and at 1- and 5-year follow-ups. Clinical and radiologic data were evaluated for all types of implants. The Wilcoxon signed rank test, least significant differences, and Mann-Whitney U were used to test for statistically significant differences (P < .005). RESULTS: Twenty-four patients and 62 implants were evaluated after 5 years. The mean marginal bone loss was 0.20 ± 0.40 mm, 0.21 ± 0.05 mm, and 0.25 ± 0.36 mm after 1 year and 0.32 ± 0.22 mm, 0.31 ± 0.26 mm, and 0.42 ± 0.36 mm after 5 years for the Straumann, Astra, and Thommen groups, respectively. After 5 years, the mean peri-implant probing depth level was 1.75 ± 0.49 mm, 1.87 ± 0.48 mm, and 1.92 ± 0.57 mm for the Straumann, Astra, and Thommen groups, respectively. No peri-implantitis was detected after 5 years of loading. CONCLUSION: All groups of implants showed a stable peri-implant probing depth and marginal bone level. The survival rate was high and bone loss was low at 5 years; thus, early loading may be a useful procedure that allows reduction in treatment time.

Comparison of Root Surface Wear and Roughness Resulted from Different Ultrasonic Scalers and Polishing Devices Applied on Human Teeth: An In-Vitro Study.

The aim of the present study was to compare the root surface wear and roughness, resulted from the professional dental hygiene instruments, including ultrasonic dental scalers, rubber prophy cups, and nylon bristle brushes, on the extracted human mandibular incisor teeth. Teeth (n = 80) were randomly assigned into eight groups according to the applied scaler type (Ma = Magnetostrictive, Pi = Piezoelectric), degree of power (M = Medium, F = Full), and angulation (0° and 45°). In the second stage, the specimens (n = 40) were further divided into two groups according to the applied polishing device (nylon bristle brush or rubber prophy cup). Laser scanner and contact profilometer devices were used for the surface analysis. Both ultrasonic instruments tested in our study produced rougher surfaces when full power was used at a 0° angle (p < 0.01). The highest wear (0.82 ± 0.07 mm3) and roughness values (0.30 ± 0.01 µm) were detected in the PiF0 group. Polishing performed with a rubber prophy cup resulted in almost twice the wear as well as a smoother surface when compared to polishing performed with a nylon bristle brush (p < 0.001). Variations in the application parameters of ultrasonic scalers and the type of polishing instrument might lead to significantly different root-surface characteristics.

Current status of zirconia-based all-ceramic restorations fabricated by the digital veneering technique: a comprehensive review.

OBJECTIVES: Delamination and chipping are major complications of veneering material on zirconia-based all-ceramic restorations. The digital veneering technique was introduced to overcome these complications as both zirconia frameworks and veneering ceramic are fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM). The aim of this review is to report all articles that evaluate zirconia-based all-ceramic restorations fabricated by the digital veneering technique. Three different digital veneering techniques were detected: the Lava DVS Digital Veneering System (3M ESPE), the Rapid Layer Technology (Vita Zahnfabrik), and the CAD-on technique (Ivoclar Vivadent). There are also some modifications of these techniques in the literature. MATERIALS AND METHODS: For this review, a comprehensive literature search was conducted. Detected studies are reported according to fracture resistance, flexural strength, wear performance, shear bond strength, microtensile bond strength, mechanical performance of restorations on implant abutments, marginal fit, color reproducibility, and clinical success for all types of digital veneering techniques. RESULTS AND CONCLUSIONS: Anatomical framework design and digital veneering using lithium disilicate and fusion porcelain might decrease the risk of chipping and delamination of veneering ceramic on zirconia-supported all-ceramic restorations. However, this result is mainly supported by in vitro studies. More clinical studies with a large sample size, longer follow-up period, and different fixed dental prosthesis designs are needed.

Clinical and Radiographic Evaluation of Early Loaded Maxillary Anterior Implants: Three-Year Follow-up.

The aim of this study was to evaluate clinical and radiologic results up to 3 years in patients treated with early loading of anterior implants supporting single-tooth all-ceramic restorations. Twenty-four patients were treated with 29 screw-type implants in the anterior maxilla. The implants were evaluated by clinical and radiographic parameters. Clinical parameters Plaque Index (PI), Sulcus Bleeding Index (BI), peri-implant probing depth (PD), and marginal bone loss (MBL) were recorded. At the recall examinations, all implants were successfully integrated, demonstrating healthy peri-implant soft tissues as documented by standard clinical parameters. No biologic complications were observed. There was no statistically significant increase in MBL between the baseline and recall stages (P > .05). Early loaded maxillary anterior implants supporting single-tooth restorations reveal successful clinical and radiographic outcomes when treatment steps were performed.

Clinical and radiographic evaluation of early loaded maxillary anterior single-tooth bone-level implants.

PURPOSE: The aim of this study was to evaluate the clinical and radiographic outcomes of early loaded platform-switched implants in the anterior maxilla. MATERIALS AND METHODS: In this study, patients were treated with implants that supported all-ceramic single-tooth crowns and were followed for 2 to 4 years. Implants were evaluated on the basis of clinical and radiographic parameters, including Plaque Index, Sulcus Bleeding Index, peri-implant probing depths (PDs), Papilla Index, soft tissue recession, and marginal bone levels. Statistical analyses were performed. RESULTS: Fifty-five implants were placed in 47 patients. At the recall examinations, all implants had successfully integrated, demonstrating healthy peri-implant soft tissues as documented by standard clinical parameters. At the time of recall, 7 implants had been followed for 4 years, 30 implants for 3 years, and 18 implants for 2 years. Plaque accumulation scores of 2 and 3 were not noted at any point during the study. At baseline, the mean PD was 2.1 ± 0.6 mm, at 2 years it was 2.2 ± 0.6 mm, at 3 years it was 2.2 ± 0.6 mm, and at 4 years (7 implants), the mean PD was 1.9 ± 0.4 mm. There were no statistically significant differences between time intervals. Complete papilla fill was seen for 49 implants. All implants showed less than 0.5 mm of marginal bone loss; mean bone loss at the time of final recall was 0.12 ± 0.22 mm. Seven implants showed an increase in the level of bone contact. There were no statistically significant differences over time. CONCLUSION: Bone-level implants with a platform-switched design are a successful treatment modality for anterior single-tooth implants.

Esthetic outcome evaluation of maxillary anterior single-tooth bone-level implants with metal or ceramic abutments and ceramic crowns.

PURPOSE: The aim of this study was to evaluate the treatment outcome of implants placed in the maxillary anterior segment. MATERIALS AND METHODS: Patients were treated with bone-level implants (Straumann Bone Level Implant, Institut Straumann) that supported all-ceramic single crowns and were followed for 2 to 4 years. Titanium or ceramic abutments were used according to the quality of the soft tissue at each site. Esthetic parameters were recorded to assess treatment outcomes. Pink esthetic scores (PES) and white esthetic scores (WES) were used to evaluate the esthetic outcome of anterior single-tooth implant-supported crowns. Patient satisfaction was also evaluated by means of a questionnaire. RESULTS: Fifty-five implants were placed in 47 patients. At the recall examinations, all implants were confirmed to have successfully integrated and demonstrated healthy peri-implant soft tissues, as documented by generally accepted clinical parameters. Overall, the esthetic results were considered favorable, and there were no significant differences between restorations with ceramic or titanium abutments. WES values were slightly superior to PES values. None of the implants had mucosal recession. CONCLUSION: Objective and subjective evaluation of maxillary bone-level implants in the esthetic zone yielded satisfactory results. Pleasing esthetic outcomes and stable facial soft tissues were achieved.

Marginal and internal adaptation of different superstructure and abutment materials using two different implant systems for five-unit implant-supported fixed partial dentures: an in vitro study.

PURPOSE: To evaluate the marginal and internal adaptation of five-unit implant-supported fixed partial dentures with different superstructure and abutment materials with two different implant systems. MATERIALS AND METHODS: Two mandibular epoxy resin models (one for each implant system) were fabricated, and implants were inserted in the canine, first premolar, and first molar regions. Thirty impressions of each model were then made. The 30 models of each group were divided into three subgroups: group 1, titanium abutment with metal (nickel-chromium) framework; group 2, titanium abutment with zirconium framework; and group 3, zirconium abutment with zirconium framework. The replica technique was used to examine the marginal and internal gap values. For each restoration, 20 measurements were performed, and the data were evaluated statistically using analysis of variance and the least significant difference post hoc test. RESULTS: The highest values for internal adaptation were observed at the occlusal surface in all groups. There were statistically significant differences in marginal measurements between subgroups. The smallest gaps were found in group 1 (79.361 µm), and the largest gaps were found in group 3 (131.242 µm). CONCLUSIONS: In this study, marginal and internal gap measurements were 79 to 131 µm. The marginal discrepancy of the tested materials could be considered clinically acceptable.

The effect of different restorative and abutment materials on marginal and internal adaptation of three-unit cantilever implant-supported fixed partial dentures: an in vitro study.

PURPOSE: Passive fit is generally assumed to be a significant prerequisite for long-term implant success. The aim of this study was to evaluate the precision fit of three-unit implant-supported fixed partial dentures with different restorative and abutment materials on two implant systems: the Straumann and Astra Tech. MATERIALS AND METHODS: Two mandibular epoxy resin models (one for each implant system) were fabricated, and two implants were inserted at the first and second molar region. Poly(vinyl siloxane) impression material was used to make the dental impression. For each implant system, fifteen models were fabricated, and each group was divided into three subgroups (group 1: titanium abutment with metal framework, group 2: titanium abutment with zirconium framework, group 3: zirconium abutment with zirconium framework). The replica technique was used to examine the marginal and internal gap values. For each restoration, 20 measurements were performed, totaling 1200 measurements for all groups. Data were evaluated statistically using ANOVA and LSD post hoc test (p < 0.05). RESULTS: The highest values at internal adaptation measurements were found at the occlusal surface for all groups. When the mean values of the marginal measurements were assessed, the lowest measurements were found in group 3 (51.416 µm), and the highest values were found in group 1 (79.394 µm). There were statistically significant differences between subgroups for marginal measurements (p < 0.05). CONCLUSIONS: As included in our study, marginal measurement values were found to be 46 to 87 µm. The marginal discrepancy of the tested materials could be considered clinically acceptable.