Hyperbaric oxygen therapy for the placement of dental implants in irradiated patients: systematic review and meta-analysis.

This study was a systematic review with meta-analysis to evaluate the influence of hyperbaric oxygen therapy (HBOT) on the survival of dental implants placed in patients who had had radiotherapy for cancer of the head and neck. A systematic literature search was conducted using the PubMed/Medline, Science Direct, Embase and the Cochrane Library, between January 1985 and July 2018. The study observed the PRISMA (Preferred Reporting Items for Systematic review and Meta-Analysis) declaration and norms, and the systematic review was duly recorded in the PROSPERO (International prospective register of systematic reviews) database. Inclusion and exclusion criteria were applied, and all articles were selected on the basis of PICO questions. The process of eligibility and quality evaluation yielded three studies for statistical analysis. Based on the survival rates, there was no evidence that the risk of an implant failing was different between the patients who received HBOT and those who did not. Moreover, the risk of an implant failing did not depend on the anatomical site. HBOT exerted no beneficial influence on the survival rates of implants placed in irradiated patients, and the risk of an implant failing did not depend on its location.

Implant Placement in Patients under Treatment with Rivaroxaban: A Retrospective Clinical Study.

The management of patients under treatment with Direct Oral Anticoagulants (DOACs) has led clinicians to deal with two clinical issues, such as the hemorrhagic risk in case of non-interruption or the risk of thromboembolism in case of suspension of the treatment. The primary aim of this retrospective study was to evaluate the incidence of perioperative bleeding events and healing complications in patients who were under treatment with Rivaroxaban and who received dental implants and immediate prosthetic restoration. Patients treated with Rivaroxaban (Xarelto 20 mg daily) and who needed implant rehabilitation were selected. Four to six implants were placed in mandibular healed sites or fresh extraction sockets. All patients, in agreement with their physicians, interrupted the medication for 24 h and received implants and immediate restorations. Twelve patients and 57 implants were analyzed in the study. No major postoperative bleeding events were reported. Three patients (25%) presented slight immediate postoperative bleeding controlled with compression only. The implant and prosthetic survival rate were both 100% after 1 year. Within the limitations of this study, multiple implant placement with an immediate loading can be performed without any significant complication with a 24 h discontinuation of Rivaroxaban, in conjunction with the patient's physician.

Implant stability in patients treated with platelet-rich fibrin and bovine bone substitute for alveolar ridge preservation is associated with peripheral blood cells and coagulation factors.

AIMS: The aim of the present study was to assess the association between dental implant stability and peripheral blood cell composition and levels of coagulation factors in patients treated with alveolar ridge preservation with platelet-rich fibrin (PRF) and bovine bone substitute. MATERIALS AND METHODS: Fifty patients were included between 2015 and 2017. PRF was prepared from autologous blood, in which blood cells and coagulation factor levels were measured. PRF and bovine bone were placed in the socket, followed by closure with PRF membrane. Implants were placed 14 (±2.5) weeks postextraction. The implant stability quotient was measured at t = 0, t = 10 days, t = 7 weeks, and t = 17 weeks by resonance frequency analysis. RESULTS: Erythrocyte count was inversely associated with PRF membrane length, but not with implant stability. Conversely, platelet count did not correlate with membrane size but inversely correlated with implant stability at 7 and 17 weeks. In addition, implant stability was directly correlated with levels FXIII (t = 0, p < .01), active von Willebrand factor (VWF; t = 0 and 7 weeks, p < .05), and total VWF (t = 7 weeks, p = .012). CONCLUSION: Implant stability following alveolar ridge preservation with PRF and bovine bone substitute is associated with circulating blood cells and coagulation factors. In particular, fibrin structure, VWF, and FXIII may be important modulators of implant stability.

Influence of green tea extract in the color of composite resin restorations.

The aim of this study was to evaluate the color change of composite resin restorations in Class I cavity preparation with different depths, submitted to challenge of thermocycling in coffee, after the use of green tea extract (EGCG) as treatment on the dentin surface. Forty-eight human molars were divided into 6 groups according to dentin treatment and depth of restoration (n = 8): Group C3- Control/3 mm; Group C4- Control/4 mm; Group C5- Control/5 mm; Group EGCG3- EGCG/3 mm; Group EGCG4- EGCG/4 mm; and Group EGCG5- EGCG/5 mm. The teeth of the control groups were restored by the bulk fill technique (Filtek Bulk Fill), conditioning the dentin surface only with universal bonding system (Single Bond Universal). The teeth of the EGCG groups were also restored by the bulk filling technique, but conditioning the dentin surface with 0.5% EGCG for 30 s prior to the application of the adhesive system. Initial and final color readings were performed according to the CIE L*a*b* scale in UV-2450 spectroscope, before and after challenge of thermal cycling in coffee. The color change (ΔE) was then calculated based on the formula ΔE = [(ΔL*)2+(Δa*)2+(Δb*)2]½. The ΔE data were submitted to statistical tests of normality, two-way ANOVA and Tukey test to compare the means (p < 0.05). There was no statistically difference for both study factors analyzed (EGCG application and restoration depth), as well as the interaction between both, after aging in coffee (p > 0.05). It was concluded that the previous application of EGCG did not cause a significant color change at the dentin-resin interface.

Treatment of the Complete Edentulous Atrophic Maxilla: The Tall Tilted Pin Hole Placement Immediate Loading (TTPHIL)-ALL TILT™ Implant Option.

AIM: A severely atrophied maxilla presents serious limitations for conventional implant placement and the reconstruction of which requires extensive surgical treatments. This original article presents an overview of this evidence-based technique used for maxillary rehabilitation. BACKGROUND: Growing patients' needs to regain proper oral function with limited surgical effort presents a challenge to the surgeon for implant placement in harmony with the planned prosthesis. Different techniques and protocols have been put forward through the ages to improve implant survival, osseointegration, and quality of life. A new technique-Tall Tilted Pin Hole Immediate Loading (TTPHIL-ALL TILT™ technique)-utilizes angulated long bicortical tapered implants placed in a flapless way in immediate loading with screw-retained prosthetic solutions. TECHNIQUE: TTPHIL-ALL TILT™ technique involves flapless subcrestal bicortical placement of a total of six tall threaded tilted implants engaging the nasal cortex and the pterygoid pillars, rigidly splinted maintaining adequate anteroposterior spread, achieving proper primary stability, fit for immediate loading. Screw-retained prosthetic solutions are provided with the elimination of distal cantilever. CONCLUSION: The TTPHIL-ALL TILT™ technique can facilitate surgical rehabilitation of patients with maxillary resorption, as an alternative to other graft less and grafting procedures. CLINICAL SIGNIFICANCE: TTPHIL-ALL TILT™ technique provides a graftless solution for the challenging resorbed maxillary edentulous ridges. By following this protocol, primary stability is achieved which gives way for immediate loading satisfying the patient's functional and aesthetic needs.

Ceramic implant fracture: A clinical report.

This clinical report describes the presentation of a fractured ceramic dental implant. The fractured implant segment was examined by scanning electron microscopy and energy dispersive spectroscopy. Energy dispersive spectroscopy confirmed that the fractured implant was made of alumina. Although alumina implants were withdrawn from the market because of poor survival rates, clinical reports of their complications are rare.

A Prospective Clinical Study of Alumina-Toughened Zirconia Abutments for Implant-Supported Fixed Restorations with a Mean Follow-up Period of 6.9 Years.

PURPOSE: The goal of this study was to compute the estimated cumulative survival and success rates of alumina-toughened zirconia (ATZ) abutments used for external connection-type implant-supported fixed dental prostheses (FDPs) after a mean follow-up of 6.9 years (82.3 months). MATERIALS AND METHODS: From May 1998 to July 2016, patients who provided informed consent and received implant-supported restorations with ATZ abutments were recruited. Clinical performance of zirconia abutments was evaluated using survival analysis. Failure was defined as the removal of the restoration due to zirconia abutment fracture, and complications included both failure and abutment screw problems. Survival and success were the counterparts of failure and complications, respectively. The effects of restoration-related factors (restored area, type of prosthesis, and implant system) on the survival and success of the abutments were estimated. RESULTS: A total of 231 patients were included in this study. One hundred twenty-six implant-supported single-unit and 204 multiple-unit FDPs were evaluated. All the placed implants had the external hex connection. The estimated cumulative 5-year, 7-year, and 10-year survival rates (95% confidence interval [CI]) of zirconia abutment-supported FDPs were 97.3% (95.5% to 99.1%), 96.8% (94.8% to 98.8%), and 94.1% (90.4% to 97.8%), respectively. The estimated cumulative 5-year, 7-year, and 10-year success rates (95% CI) were 94.1% (91.4% to 96.8%), 90.8% (87.3% to 94.3%), and 80.1% (73.6% to 86.6%), respectively. The type of prosthesis (P = .001) and implant system (P < .001) were the significant factors in the success of zirconia abutment-supported FDPs. CONCLUSION: Prefabricated ATZ abutments have a high predictability of survival at 10 years when used in implant-supported FDPs that replace both anterior and posterior teeth. However, the success of zirconia abutments was significantly influenced by the type of prosthesis and implant system.

Interfacial Fracture Toughness of Adhesive Resin Cement-Lithium-Disilicate/Resin-Composite Blocks.

PURPOSE: Resin composite blocks (RCB) are advocated as alternative to ceramic blocks (CB). Prior to use, adherence to these materials should characterized. This study aimed to test the null hypothesis (H0 ) that material and surface treatment combinations do not influence interfacial fracture toughness (KIC ) of a self-cured adhesive resin cement [RelyX Ultimate (RXU)] to RCB or CB, under nonaged and aged conditions. MATERIALS AND METHODS: Two RCB, Lava Ultimate (LU) and Enamic (EN), and one CB, IPS e.max Press (EMP) were used. Half-size [(6 × 6 × 6 × 6 mm)] specimens were prepared for EMP (n = 30), EN (n = 30), and LU (n = 60). RCB specimens were prepared by wet cutting/grinding, while CB specimens were pressed. Surfaces of EMP and EN were preconditioned with hydrofluoric acid (5%); surfaces of LU were sandblasted with either 27 µm alumina (LUS) or 30 µm silica-modified alumina Rocatec soft (LUR). All specimens were bonded with Scotchbond Universal adhesive and RXU. Additionally, twenty (4 × 4 × 4 × 8 mm) RXU specimens were prepared. All specimens were stored in water at 37°C and tested after 1 and 60 days. Interfacial KIC was determined with the notchless triangular prism specimen KIC test. Results were analyzed with two-way ANOVA and Scheffé multiple means comparisons (α = 0.05). Preconditioned and selected fractured surfaces were characterized with scanning electron microscopy. RESULTS: At 24 hours, LUS-RXU and LUR-RXU had significantly higher interfacial KIC than EN-RXU and EMP-RXU and were not different from KIC of RXU. Aging lead to a significant decrease in KIC of RXU and interfacial KIC of LUS-RXU, LUR-RXU, and EMP-RXU; interfacial KIC of EN-RXU was not affected. Based on the results, H0 was rejected. CONCLUSION: Under the conditions of this study, at 24 hours, interfacial KIC of LUS-RXU and LUR-RXU was superior to EMP-RXU and EN-RXU. Aging in water at 37°C did not affect interfacial KIC of EN-RXU but adversely affected KIC of RXU and the other interfacial KIC . CLINICAL IMPLICATIONS: The results suggest that RXU and its adherence to LU and EMP deteriorates upon exposure to water at 37°C. In making clinical decisions related to material selection, practitioners should consider in vitro results.

Influence of Particle and Air-Abrasion Moment on Y-TZP Surface Characterization and Bond Strength.

PURPOSE: To evaluate the influence of particle and air-abrasion on the surface characterization and shear bond strength (SBS) of a Y-TZP ceramic with a resin cement. MATERIALS AND METHODS: Y-TZP specimens were air-abraded with 50 µm alumina particles; 120 µm alumina particles; 30 µm silica-coated alumina particles (Rocatec Soft); 110 µm silica-coated alumina particles (Rocatec Plus). Air-abrasion was performed before (BS); after (AS); before and after (BAS) zirconia sintering. Surface characterization included roughness (n = 10), wettability (n = 10), morphology (n = 2), and elemental composition (n = 2). For SBS (n = 11), composite resin discs were bonded to the air-abraded and silane-treated zirconia surface, with the resin cement RelyX ARC. Failure mode was determined. Roughness, wettability, and SBS data were analyzed by two-way ANOVA with pairwise interaction and Tukey's test (α = 0.05). RESULTS: Air-abrasion performed with coarser particles at BS and BAS moments provided the highest roughness values, while the lowest roughness values were observed with particles combined with AS moment (p < 0.01). Rocatec Plus provided lower contact angle than the 120 µm alumina particles (p = 0.013), and BAS exhibited lower contact angle than BS (p = 0.002). The combinations 120 µm/BS and the silica-coated alumina particles/AS and /BAS showed the highest SBS (p < 0.05). The combination of each particle/BAS was statistically similar to the same particle/AS. Failure mode was 100% adhesive for all groups. The interaction particle size/air-abrasion moment determined the morphological pattern. Silicon was observed only in the Rocatec groups. CONCLUSIONS: Roughness was influenced by the particle size and was higher when the zirconia was air-abraded in its green stage. The particle composition played an important role in the wettability and both studied air-abrasion moments provided similar wettability than the one in which air-abrasion is usually performed. The highest SBS values were observed in the three moments, by using certain particles for each moment.

Miniaturized Electromagnetic Device Abutment Improves Stability of the Dental Implants.

BACKGROUND: The overall success and predictability of dental implant treatment hinge on the primary stability, direct bone-to implant contact formation, and quantity and/or quality of residual bone. Pulsed electromagnetic field has been reported to increase bone regeneration in various clinical situations. Therefore, it was hypothesized that devices which could locally generate a Pulsed electromagnetic field would stimulate bone healing and increase bone density surrounding implants. OBJECTIVE: To retrospectively assess the effects of the miniaturized electromagnetic device (MED) on the implants stability for the first time in human subjects, in a prospective case controlled series. METHODS: Twelve consecutive patients (28 implants) were included in the study.Twelve MED healing caps and 16 regular control healing caps were inserted. Resonance frequency analysis (RFA) was performed at implant placement and abutment connection and an implant stability quotient value was given for each implant. RESULTS: Twenty-eight dental implants were included in the current study. Maxillary implants stability was significantly higher with MED healing cups compared with controls at 15 days postimplantation (66.2 vs 62.1, P = .0008). Resonance frequency analysis test performed at 30 days postimplantation demonstrated significantly increased stability in MED as compared with the control 73.5 ±â€Š3.2 vs 66.7 ±â€Š4.8 in mandibular implants and 74 ±â€Š1.7 vs 65 ±â€Š2.3 in maxillary implants. At the 50 days postimplantation, RFA tests revealed markedly higher stability of the maxillary implants with MED active healing caps compared with nonactive 75.4 ±â€Š5.1 vs 68.5 ±â€Š8.5, respectively. CONCLUSIONS: We conclude that MED-abutment implants demonstrated a superior stability during the early phase of healing as compared with standard implants.

How to improve root canal filling in teeth subjected to radiation therapy for cancer.

The aim of this study was to evaluate the influence of radiation therapy on root canal sealer push-out bond strength (BS) to dentin and the sealer/dentin interface after different final irrigation solutions (NaOCl, EDTA, and chitosan). Sixty-four maxillary canines were distributed into two groups (n=30): non-irradiated and irradiated with 60 Gy. Canals were prepared with Reciproc-R50 and subdivided (n=10) for final irrigation (NaOCl, EDTA, chitosan) and filled. Three dentin slices were obtained from each root third. The first slice of each third was selected for BS evaluation, and the failure mode was determined by stereomicroscopy. SEM analysis of the sealer-dentin interface was performed in the remaining slices. Two-way ANOVA and Tukey's tests (α=0.05) were used. Lower BS (P<0.0001) was obtained after irradiation (2.07±0.79 MPa), regardless of the final irrigation solution used. The NaOCl group (P<0.001) had the lowest BS in the irradiated (1.68±0.72) and non-irradiated (2.39±0.89) groups, whereas the EDTA (irradiated: 2.14±0.77 and non-irradiated: 3.92±1.54) and chitosan (irradiated: 2.37±0.73 and non-irradiated: 3.51±1.47) groups demonstrated a higher BS (P<0.05). The highest values were observed in the coronal third (3.17±1.38) when compared to the middle (2.74±1.36) and apical ones (2.09±0.97)(P<0.0001). There were more cohesive failures and more gaps in irradiated specimens, regardless of the final solution. The present study showed that radiation was associated with a decrease in BS, regardless of the final solution used, whereas chitosan increased BS in teeth subjected to radiation therapy.

Laser-assisted removal of all ceramic fixed dental prostheses: A comprehensive review.

OBJECTIVE: The aim of this comprehensive review was to assess the effectiveness of erbium lasers in the removal of all ceramic fixed dental prostheses (FDPs). OVERVIEW: Indexed databases were searched without language or time restriction up to and including December 2017 using different combinations of the following keywords: "lasers"; "phototherapy"; "crowns"; "prostheses and implants"; "inlays"; "ceramics"; "dental porcelain"; "zirconium"; "removal"; "debonding"; "fixed dental prostheses"; "veneers"; "laminates"; and "fixed bridge." All levels of available evidence including experimental studies, case reports and case series were included. Six clinical studies reporting a total of 13 cases and 6 experimental studies were included. Results from all studies showed that erbium lasers are effective reducing the shear bond strengths of all ceramic FDPs, in terms of easy removal of the restorations with none or minimal damage to teeth or ceramic surfaces. CONCLUSION: Laser-assisted removal of all ceramic FDPs is a promising treatment protocol. Further well-designed controlled clinical trials and longitudinal prospective studies are needed to determine the precise laser parameters and duration of irradiation that could be used for removal of ceramic restorations with varying thicknesses. CLINICAL SIGNIFICANCE: Benefits of lasers over mechanical instrumentation for crown removal encompass efficient restoration retrievability without restoration or teeth surfaces damages; and relatively easier and time effective procedure with no prerequisite for anesthetic agents. It is however imperative for clinicians to be well-trained and exhibit adequate knowledge regarding recommended power settings and laser-safety parameters with reference to interactions between light and different tissues and ceramics.

How to improve root canal filling in teeth subjected to radiation therapy for cancer

Abstract The aim of this study was to evaluate the influence of radiation therapy on root canal sealer push-out bond strength (BS) to dentin and the sealer/dentin interface after different final irrigation solutions (NaOCl, EDTA, and chitosan). Sixty-four maxillary canines were distributed into two groups (n=30): non-irradiated and irradiated with 60 Gy. Canals were prepared with Reciproc-R50 and subdivided (n=10) for final irrigation (NaOCl, EDTA, chitosan) and filled. Three dentin slices were obtained from each root third. The first slice of each third was selected for BS evaluation, and the failure mode was determined by stereomicroscopy. SEM analysis of the sealer-dentin interface was performed in the remaining slices. Two-way ANOVA and Tukey's tests (α=0.05) were used. Lower BS (P<0.0001) was obtained after irradiation (2.07±0.79 MPa), regardless of the final irrigation solution used. The NaOCl group (P<0.001) had the lowest BS in the irradiated (1.68±0.72) and non-irradiated (2.39±0.89) groups, whereas the EDTA (irradiated: 2.14±0.77 and non-irradiated: 3.92±1.54) and chitosan (irradiated: 2.37±0.73 and non-irradiated: 3.51±1.47) groups demonstrated a higher BS (P<0.05). The highest values were observed in the coronal third (3.17±1.38) when compared to the middle (2.74±1.36) and apical ones (2.09±0.97)(P<0.0001). There were more cohesive failures and more gaps in irradiated specimens, regardless of the final solution. The present study showed that radiation was associated with a decrease in BS, regardless of the final solution used, whereas chitosan increased BS in teeth subjected to radiation therapy.

Influence of root dentin treatment on the push-out bond strength of fibre-reinforced posts

This study evaluates the influence of root dentin treatment with NaOCl alone and combined with EDTA, with and without ultrasound activation, on the push-out bond strength (BS) of fiber-reinforced posts in weakened roots, cemented with RelyX or Panavia. The root canals of 42 maxillary canines were instrumented with Reciproc and 2.5% NaOCl. In the coronal 12mm of all canals, experimental weakening of the roots was produced by reducing dentin thickness with 2.44mm diameter diamond burs. The roots were assigned to 3 groups (n = 14) according to root dentin treatment: 2.5% NaOCl; 2.5% NaOCl + 17% EDTA; and 2.5% NaOCl + 17% EDTA, with solutions agitated using passive ultrasonic irrigation. After cementation of the fiber-reinforced posts the roots were divided in thirds. The first slice of each third was used for the push-out BS test, the second slice for confocal laser scanning microscopy and dentin microhardness (Knoop) analysis. Data were analysed by a two-way ANOVA and Tukey test (a = 0.05). NaOCl + EDTA provided highest BS values than NaOCl (p < 0.0001). Specimens cemented with Panavia presented significantly higher BS than those with RelyX in the three root thirds (p < 0.0001). The highest BS values occurred in the cervical third (p < 0.001). Ultrasound-activated NaOCl + EDTA promoted the greatest reduction in dentin microhardness, followed by NaOCl/EDTA and NaOCl. Ultrasonic activation of NaOCl and EDTA reduced root dentin microhardness, but did not improve the push-out BS of resin-based cements. Panavia presented higher BS than RelyX. RelyX was not influenced by the root dentin treatment protocols.

Fifteen-year survival of anterior all-ceramic cantilever resin-bonded fixed dental prostheses.

PURPOSE: The aim of this follow-up study was to report the long-term outcome of all-ceramic cantilever resin-bonded fixed dental prostheses (RBFDPs). MATERIALS AND METHODS: In 16 patients (mean age of 33.3±17.5years) 22 RBFDPs made from a glass-infiltrated alumina ceramic (In-Ceram) were inserted with a phosphate monomer containing luting agent after air-abrasion of the retainer wings. The abutment preparation included a shallow groove on the cingulum and a small proximal box. The restorations replacing 16 maxillary and 6 mandibular incisors were followed over a mean observation time of 188.7 months. RESULTS: No restoration debonded. Two RBFDPs fractured and were lost 48 and 214 months after insertion, respectively. The 10-year and 15-year survival rates were both 95.4% and dropped to 81.8% after 18 years. CONCLUSION: Anterior all-ceramic cantilever RBFDPs exhibited an excellent clinical longevity.

In Vitro Comparison of the Bond Strength between Ceramic Repair Systems and Ceramic Materials and Evaluation of the Wettability.

PURPOSE: When fracture of an all-ceramic restoration occurs, it can be necessary to repair without removing the restoration. Although there are many studies about the repair of metal-ceramic restorations, there are few about all-ceramic restorations. The aim of this study was to evaluate the shear bond strength between ceramic repair systems and esthetic core materials and to evaluate the wettability of all-ceramic core materials. MATERIALS AND METHODS: Disk-like specimens (N = 90) made of three dental ceramic infrastructure materials (zirconia ceramic, alumina ceramic, glass ceramic) were polished with silicon carbide paper, prepared for bonding (abrasion with 30 µm diamond rotary cutting instrument). Thirty specimens of each infrastructure were obtained. Each infrastructure group was divided into three subgroups; they were bonded using 3 repair systems: Bisco Intraoral Repair Kit, Cimara & Cimara Zircon Repair System, and Clearfil Repair System. After 1200 thermocycles, shear bond strength was measured in a universal testing machine at a 0.5 mm/min crosshead speed. In addition, the contact angle values of the infrastructures after surface treatments were examined for wettability. Data were analyzed by using ANOVA and Tukey post hoc tests. RESULTS: Although there were no significant differences among the repair systems (p > 0.05) in the glass ceramic and zirconia groups, a significant difference was found among the repair systems in alumina infrastructure (p < 0.001). There were no statistically significant differences among the infrastructures (p > 0.05); however, a statistically significant difference was found among the repair systems (p < 0.05). No difference was found among the infrastructures and repair systems in terms of contact angle values. CONCLUSIONS: Cimara & Cimara Zircon Repair System had higher bond strength values than the other repair systems. Although no difference was found among the infrastructures and repair systems, contact wettability angle was decreased by surface treatments compared with polished surfaces.

Implant osseointegration in irradiated bone: an experimental study.

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate the effect of radiotherapy on the osseointegration of dental implants in the tibia and the action of platelet-rich plasma (PRP) as an adjuvant therapy. MATERIAL AND METHODS: A total of 18 rabbits received two implants in each tibial epiphysis, totalizing 72 implants. The control group (group I) was composed by six rabbits and did not receive radiotherapy. The test groups (II and III) received a single dose of 1727 cGy. Group II was composed by six irradiated animals and group III by six animals that received irradiation and PRP during implant placement. The implant success rate, the bone-implant contact (BIC), and the bone volume were analyzed. RESULTS: There was no osseointegration in four of the implants, three in group II and one in group III. Total BIC was significantly higher in group I, when compared to the other groups. There was a significant difference of osteoid BIC only between irradiated animals (group II, 8.5%; group III, 4.7%; p = 0.001). On the other hand, the mineralized BIC was significantly higher in group I. Furthermore, group II had a lower mineralized BIC than group III (p = 0.002). Bone volume was higher in the control group (41.3%), followed by group III (33.4%) and II (25.1%), with differences between groups I and II (p = 0.001) and groups II and III (p = 0.022). CONCLUSIONS: The present study showed that both the bone volume and BIC were higher in the control group. However, the failure rates of the implants were low in both irradiated groups. The PRP was a positive adjuvant in the osseointegration process.

Influence of root dentin treatment on the push-out bond strength of fibre-reinforced posts

Abstract This study evaluates the influence of root dentin treatment with NaOCl alone and combined with EDTA, with and without ultrasound activation, on the push-out bond strength (BS) of fiber-reinforced posts in weakened roots, cemented with RelyX or Panavia. The root canals of 42 maxillary canines were instrumented with Reciproc and 2.5% NaOCl. In the coronal 12mm of all canals, experimental weakening of the roots was produced by reducing dentin thickness with 2.44mm diameter diamond burs. The roots were assigned to 3 groups (n = 14) according to root dentin treatment: 2.5% NaOCl; 2.5% NaOCl + 17% EDTA; and 2.5% NaOCl + 17% EDTA, with solutions agitated using passive ultrasonic irrigation. After cementation of the fiber-reinforced posts the roots were divided in thirds. The first slice of each third was used for the push-out BS test, the second slice for confocal laser scanning microscopy and dentin microhardness (Knoop) analysis. Data were analysed by a two-way ANOVA and Tukey test (a = 0.05). NaOCl + EDTA provided highest BS values than NaOCl (p < 0.0001). Specimens cemented with Panavia presented significantly higher BS than those with RelyX in the three root thirds (p < 0.0001). The highest BS values occurred in the cervical third (p < 0.001). Ultrasound-activated NaOCl + EDTA promoted the greatest reduction in dentin microhardness, followed by NaOCl/EDTA and NaOCl. Ultrasonic activation of NaOCl and EDTA reduced root dentin microhardness, but did not improve the push-out BS of resin-based cements. Panavia presented higher BS than RelyX. RelyX was not influenced by the root dentin treatment protocols.

Marginal Fit Metal-Ceramic and In-Ceram Single Crown Cement retained in Implant-supported Abutments.

INTRODUCTION: This study evaluated the cervical fit of cemented metal-ceramic and In-Ceram implant-supported crowns, before and after the cementing procedure. MATERIALS AND METHODS: Twenty crowns cemented on implant abutments are divided into two groups (n = 10): Group 1 -cemented metal-ceramic crowns and group 2 - cemented In-Ceram crowns. The marginal adaptations before and after cementation were evaluated in a comparison microscope with an error of 1 µm. All crowns were cemented with zinc phosphate cement. RESULTS: The cervical misalignment of cemented crowns before cementation (52.65 ± 11.83 and 85.73 ± 14.06 µm) was lower than that after cementation (66.80 ± 15.86 and 89.36 ± 22.66 µm). CONCLUSION: The cementing procedure interferes with the marginal fit of cemented crowns on implant abutments, with the prosthesis having better adaptation before cementation. Cemented metal-ceramic crowns exhibited better cervical adaptation than In-Ceram crowns cemented before and after the cementing procedure. CLINICAL SIGNIFICANCE: The maintenance of gum health and the longevity of prosthetic restorations are closely related to the restoration's marginal integrity.

Pit and Fissure Sealant Retention Following Air Abrasion Preparation with Bioactive Glass and Aluminum Oxide Particles.

PURPOSE: Alumina air abrasion is an alternative for acid-etch technique for tooth preparation before placement of a fissure sealant. The aim of this study was to compare the retention of sealants placed subsequent to air abrasion with alumina and bioactive glass (BAG) particles. METHODS: Sixty-two 6-12 year old children were included in this study. Using a halfmouth design, the fissures were prepared using air abrasion with alumina particles on randomly assigned permanent mandibular or/and maxillary first molars on one side of the mouth (Group 1) and air abrasion with BAG on the contralateral side of the mouth (Group 2). Sealants were applied on 180 teeth, and were scored as missing, partially retained, and completely retained after three, six, nine and 12 months. Data were analyzed using Friedman and Wilcoxon tests (α=0.05). RESULTS: Sealant retention rates in the alumina group were higher than those in the BAG group at all time periods (P<0.001). CONCLUSIONS: Sealant retention after air abrasion with alumina particles was higher than BAG over 12 months.