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Aim The aim of this study was to test two different of experimental cements based on two types of polymerization techniques comparing them with one already well known in the market. Materials and methods Thirty intact central incisors, extracted for periodontal reasons, were selected and endodontically treated, then were randomly divided into 3 groups of 10 samples: Group 1, light cured composite experimental material with self-etch adhesive and dual polymerization activator; Group 2, dual experimental core build-up with self-etch adhesive and dual-polymer activator; Group 3 (control group), dual cement with self-etch adhesive and dual polymerization activator. One fiber post was luted into the root canal strictly following manufacturer’s instructions. Each sample was cut in slices in order to perform the push-out bond strength test with a testing machine. To express the bond strength in MegaPascals (MPa), the breaking load recorded in Newton (N) was divided by the area of the bonded interface (A) in mm2. The area of the bond interface was calculated as the area of the surface of a truncated cone using the formula: A = π (R + r) [h2 + (Rr) 2] 1/2, where R represents the major radius of the coronal post, r represents the minor radius of the apical post and h is the thickness of the slice in millimeters. The diameters and thickness of the slice were measured individually using a digital caliper with 0.01 mm precision. After the test, each slide was observed to detect the type of failure and classified as adhesive between cement and dentin (AD); adhesive between the cement and the post (AP); fracture of the sample, cohesive inside the post and dentin (FR); cohesive in cement (CC); mixed (M). Results Group 2 recorded the highest values of adhesion strength, group 1 the lowest. There were no statistically significant differences among groups 1 and 2 and controls. The most common failure mode was the mixed one and the less frequent was the adhesive type between the post and the cement. Conclusions Within the limitations of this study, it can be concluded that the bond strength of experimental resin cements is comparable to that of a cement marketed by the same manufacturer, used here as a control and well known in the market.

Background: The reduction in joint load is a potential beneficial factor in managing osteoarthritis of the temporomandibular joint (TMJ). This paper aims to compare the effectiveness of the intramuscular injection of botulinum toxin (BTX-A) as an adjunct to TMJ arthrocentesis plus viscosupplementation with arthrocentesis plus viscosupplementation alone in the management of TMJ osteoarthritis., Methods: A pilot clinical retrospective study examined TMJ osteoarthritis treatments. Patients were divided into two groups: Group A received BTX-A injections and arthrocentesis with viscosupplementation, while Group B received only arthrocentesis with viscosupplementation. The study assessed outcomes based on mouth opening (MO), pain at rest (PR), pain at mastication (PF), and masticatory efficiency (ME) at various time points (baseline (T0), 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4)) up to 2 months after treatment., Results: The study included two groups, each with five patients. Group A received five weekly sessions of arthrocentesis plus viscosupplementation and a single BTX-A injection during the first arthrocentesis appointment. Group B underwent the five-session protocol of arthrocentesis plus viscosupplementation alone. MO, PF, PR, and ME improved quickly in T2 in both groups, but the improvement was of greater importance over the following weeks and lasted longer in Group A., Conclusions: Arthrocentesis with viscosupplementation associated with BTX-A was found to be more effective than arthrocentesis alone in improving clinical outcomes. This suggests that patients with TMJ osteoarthritis and myofascial pain may benefit from reduced muscle tone and joint load.

Objective: To assess the frequency of awake bruxism (AB) behaviors in a group of undergraduate dentistry students and correlate it with the status of anxiety and depression., Materials and Methods: The frequency of five oral behaviors (i.e., relaxed jaw muscle, teeth contact, mandible bracing, teeth clenching, teeth grinding) was evaluated using a smartphone-based ecological momentary assessment (EMA) approach. The anxiety and depression status was investigated with the four-item patient health questionnaire for anxiety and depression (PHQ-4). ANOVA with Tukey post-hoc test was used to assess the difference in frequency of AB behaviors among the four PHQ-4 groups., Results: Among the four groups, there was a statistically significant difference in the frequency of relaxed jaw muscle, teeth contact, mandible bracing, and teeth clenching, but not for teeth grinding., Conclusion: Based on this cross-sectional study's findings, psyche seems to have a determinant impact on AB behaviors, which is significantly higher in individuals with anxiety and depression traits.

Purpose: To evaluate clinical performances of two lithium disilicate systems (Initial LiSi press vs Initial LiSi Block, GC Co.) using modified United States Public Health Service (USPHS) evaluation criteria and survival rates after 4 years of clinical service., Methods: Partial adhesive crowns on natural abutment posterior teeth were made on 60 subjects who were randomly divided into two groups: Group 1: Initial LiSi press and Group 2: Initial LiSi Block. Fabrication of partial crowns was made with full analog and digital procedure in Groups 1 and 2 respectively. The restorations were followed-up for 1 and 4 years, and the modified USPHS evaluation was performed at baseline and each recall together with periodontal evaluation. Contingency tables to assess for significant differences of success over time in each group and time-dependent Cox regression to test for differences between the two groups were used and the level of significance was set at P< 0.05., Results: Regarding modified USPHS scores, all evaluated parameters showed Alpha or Bravo and no Charlie was recorded. No statistically significant difference emerged between the two groups in any of the assessed variables (P> 0.05). No statistically significant difference between scores recorded at the baseline and each recall. All modified USPHS scores were compatible with the outcome of clinical success and no one restoration was replaced or repaired, and the survival rate was 100% after 4 years of clinical service. No difference was found between traditional and digital procedure to fabricate the crowns. The two lithium disilicate materials showed similar results after 4 years of clinical service., Clinical Significance: The crowns made with the two tested lithium disilicate materials with analog and digital procedures showed 100% survival after 4 years of clinical service with no statistically significant difference using the modified USPHS scores., Competing Interests: The authors declared they had no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright©American Journal of Dentistry.)

Background: The aim of this study was to evaluate the association of perceived stress and poor sleep quality with periodontitis in a university-based cohort of individuals., Methods: A total of 235 individuals were included in this cross-sectional study. Perceived stress and sleep quality were evaluated through validated questionnaires, while periodontitis was identified with a full-mouth periodontal examination protocol using both European Federation of Periodontology/American Academy of Periodontology (EFP/AAP) and Centers for Disease Control and Prevention (CDC)/AAP case definitions. Simple and multiple linear and ordinal logistic regression analyses were performed to evaluate the association between perceived stress and sleep quality with periodontitis prevalence and severity., Results: Stage III/IV periodontitis resulted associated with both moderate/high perceived stress (odds ratio [OR] = 5.4; 95% confidence interval [CI]: 2.2-13.5; p < 0.001) and poor sleep quality (OR = 3.0; 95% CI: 1.2-7.4; p < 0.05). The interaction between moderate/high perceived stress and poor sleep quality presented a multiplicative association with stage III/IV periodontitis (EFP/AAP; OR = 5.8; 95% CI: 1.6-21.3; p < 0.001). Multiple linear regression analyses indicated a similar trend of association also with linear periodontal parameters, that is, mean clinical attachment level (CAL) and mean probing pocket depth (PPD)., Conclusions: The findings from the present study suggest that stress and poor sleep quality may exert a multiplicative effect on periodontitis prevalence and severity., (© 2023 The Authors. Journal of Periodontology published by Wiley Periodicals LLC on behalf of American Academy of Periodontology.)

PMMA (Polymethylmethacrylate) is the material of choice to fabricate denture bases. Recently, with the introduction of CAD-CAM and 3D printers in dentistry, new materials have been proposed for complete denture manufacturing., Aim: This study compared the flexural strength of different resins fabricated using different technologies (conventional, CAD-CAM-milled, and 3D-printed) and polymerization techniques., Methods: A total of 11 different resins were tested: six PMMA conventional (Acrypol R, Acrypol LL, Acrypol HI, Acrypol Fast, Acryself and Acryslef P), two milled obtained from UDMA PMMA disks (Ivotion disk and Aadva disk, control groups), two 3D-printed PMMA resins (NextDent Denture 3D+, and SprintRayEU Denture Base), and one 3D-printed composite resin (GC Temp Print). Flexural strength was measured using a universal testing machine. One-way ANOVA and Bonferroni post hoc tests were performed; the p -value was set at 0.05 to consider statistically significant differences among the groups. Spearman test was used to evaluate the correlation between polymerization technique and the flexural strength of 3D-printed resins., Results: CAD-CAM-milled specimens showed the highest flexural strength (107.87 MPa for UDMA) followed by 3D-printed composite resins (102.96 MPa). Furthermore, 3D-printed resins polymerized for 40 min with the BB cure unit showed no statistically significant differences with conventional resin groups. Moreover, in all the 3D-printed specimens, a high correlation between polymerization technique and flexural strength was found., Conclusions: In terms of flexural strength, the polymerization technique is a determinant for both acrylic and composite resins. Temp Print can be a potential alternative to fabricating removable dentures and showed promising results when used in combination with pink color resin powder.

The aim of this study was to compare the clinical results of combining a pedicle connective palatal flap coupled with the trapezoid buccal flap against the buccal flap alone in the closure of the oroantral fistula. Individuals with oroantral communication were consecutively included and eventually randomly allocated into 2 groups. In the group test, oroantral fistula was treated with the association of a buccal flap with a pedicle palatal connective tissue flap; in group control, a classic buccal sliding flap was performed. Patients' outcomes were recorded at 48 hours, 1 week, 2 weeks, and 1 month after surgery for assessment of primary (success rate) and secondary endpoints, such as experienced pain, discomfort, and complications. The success rate was 96.6% for the test group and 86.6% for the control group. No significant difference between the 2 groups could be observed regarding discomfort and pain. More pronounced pain was detected in the test group during the early healing period. This surgical procedure was demonstrated to be successful, with a high success rate and low patient discomfort., (Copyright © 2023 by Mutaz B. Habal, MD.)

The aim of this study was to assess adaptation and bonding to root canal dentin of discontinuous (short) glass fiber-reinforced composite to intra-radicular dentin (DSGFRC)., Methods: Seventy virgin human teeth were extracted and then endodontically treated; then samples were randomly divided into 7 groups (n = 10), based on the materials' combinations as follows: Group 1, a two-bottle universal adhesive + DSGFRC; Group 2, a single-component universal adhesive + DSGFRC; Groups 3 and 4, the same materials of Goups 1 and 2 were used but after cleaning of the canal walls with 17% EDTA and final irrigation with 5.25% NaOCl Ultrasound Activated (UA); Group 5, traditional prefabricated fiber posts were luted after being silanized with G-Multi Primer; Groups 6 and 7, like Group 5 but after ultrasonic irrigation (UA). All sample roots were cut 1 mm thick (n = 10) to be evaluated regarding root canal adaptation using a light microscope and scanning electron microscope (SEM) and push-out bond strength. These results were statistically analyzed by Kruskal-Wallis analysis of variance by ranks. The level of significance was set at p < 0.05., Results: Bond strength forces varied between 6.66 and 8.37 MPa and no statistically significant differences were recorded among the groups. By microscopic examination, it was noted that ultrasonic irrigation increased the adaptation of the materials to the dentin surface., Conclusions: Within the limitations of this in vitro study, it may be concluded that when DSGFRC was used for intracanal anchorage in the post-endodontic reconstruction, similar push-out retentive force and strength to those of traditional fiber posts cemented with particulate filler resin composite cements were achieved., Competing Interests: P.V. consults GC Corporation in RD and training. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

Aim: The aim of this systematic review is to evaluate the relationship between prosthodontic treatment and temporomandibular disorders (TMD)., Materials and Methods: Two clinical questions have been raised. Can prosthodontic treatment be used as a strategy to manage temporomandibular disorders? Is there any causal relationship between prosthodontic rehabilitation and the onset of TMD? A systematic search was performed in four medical databases to identify Clinical Trials (CT) and Randomized Clinical Trials (RCT) that could answer the two clinical questions., Results: Any articles fulfilling the inclusion criteria were found. Therefore, the best available evidence on TMD management and aetiology is discussed in a scoping review with focus on the relationship with prosthodontic treatment., Conclusions: Based on current scientific evidence, prosthetic rehabilitation cannot be proposed as a treatment option for TMD patients, based on the effectiveness of other more conservative options as well as the absence of association between features of dental occlusion and TMD. Thanks to the high neuro plastic adaptation skills of the stomatognathic system, prosthodontic rehabilitation cannot be identified as a direct cause of TMD, but clinicians should pay caution when performing relevant occlusal modifications., (Copyright© 2023 Dennis Barber Ltd.)

The objective of this clinical study was to collect short-term endodontic outcomes of endodontic-treated teeth (ETT) obturated with different kinds of bioceramic sealers used in combination with warm gutta-percha obturation techniques. Methods: A total of 210 endodontic treatments in 168 patients were performed. At baseline, 155 sample teeth (73.8%) showed symptoms (tenderness or pain to percussion) and 125 (59.5%) showed periapical radiolucency. Periapical radiolucency was present in 125 cases (59.5%); of these, 79 showed a lesion of 5 mm or bigger (63.2%) while lower than 5 mm in 46 cases (36.8%). Regarding ETT with radiolucency, 105 of them (84%) were in coincidence with their need for retreatment and the other 20 (16%) were necrotic teeth. The obturation techniques that were used in this study were: the continuous wave of condensation technique in 75% of cases, and carrier-based technique in 25%. Four bioceramic sealers were used: CeraSeal in 115 cases, BioRoot in 35 cases, AH Plus Bio in 40 cases, and in 20 cases, BIO-C SEALER ION. Preoperative and recall radiographs of the roots were each assigned a periapical index (PAI) score by 2 blinded, independent, and calibrated examiners. The teeth were divided into outcome categories based on the following classification: healed, unhealed, and healing. The healed and healing categories were classified as success, and the unhealed category was classified as failure on the basis of loose criteria. Minimum follow-up period was 18 months. Results: The overall success rate was 99%, with 73.3% healed, 25.7% healing, and 0.95% not healed. The success rate was 100% for initial treatment and 98.2% for retreatment. Fifty-four (N = 54) teeth showed ongoing healing. All of them were retreatment cases with periapical lesions. Regarding the success (healed and healing) versus not healed, no significant difference was found between teeth with or without periapical lesions ( p < 0.05). A statistically significant difference in the distribution of healed, healing, and not-healed teeth was found between the groups of teeth with baseline lesions < 5 mm and >5 mm in diameter ( p < 0.01) and those with sealer groups ( p < 0.01). The success rate of used bioceramic sealers was not statistically significant different (99.1%, 100%, 97.5% and 100%, respectively, for CeraSeal, BioRoot, AH Plus Bio, and BIO-C SEALER ION). Nonetheless, the distribution of healed, healing, and not-healed teeth was different between teeth sealed with different materials ( p < 0.01). From the findings of this clinical study, the following conclusion can be drawn: a correct filling of root canals made with warm gutta-percha technique combined with a bioceramic sealer allows a high success rate in endodontically treated teeth.

Background: The aim of this study was to evaluate the association between adherence to Mediterranean diet (MD) and physical activity (PA) level with the periodontal status of a University-based cohort of individuals., Methods: A total of 235 individuals were included in the study. MD adherence and PA level were registered through validated questionnaires, together with a full periodontal examination. Crude and adjusted odds ratios (ORs) [95% confidence interval] were calculated to evaluate the association between MD adherence, PA level, and periodontitis severity. A final logistic multivariate regression model was built to evaluate the impact of the combination between low MD adherence and low PA level on the prevalence of Stage III/IV periodontitis., Results: The adjusted ORs for Stage III/IV periodontitis were 1.65 [0.84 to 3.28; P = 0.42] for low PA and 5.63 [3.21 to 9.84; P = 0.00] for low MD adherence. The final logistic multivariate regression model resulted in OR = 10.23 [4.01, 26.09; P = 0.00] of having Stage III/IV periodontitis in individuals with low MD adherence and low PA., Conclusions: Individuals conducting a lifestyle characterized by the combination of low MD adherence and lack of regular exercise had 10 times the odds to have severe forms of periodontitis., (© 2022 The Authors. Journal of Periodontology published by Wiley Periodicals LLC on behalf of American Academy of Periodontology.)

Background: To determine the survival rates of endodontically treated posterior teeth (EDPT) restored with partial coverage all-ceramic crowns with or without the use of fiber posts., Methods: MEDLINE and Cochrane searches were conducted in order to identify Randomized Clinical Trials (RCTs) related to endodontically treated posterior teeth restored with partial coverage crowns. The search period was extended until February 2020 and only in vivo, human, and studies in the English language were included. A manual search was also conducted and additional articles, if found, were included in the database., Results: The initial search for the selected databases identified 495 studies, which were all screened for inclusion through titles, abstracts and full-text reading. Out of these 495 studies, only one article met the eligibility criteria and was included in this systematic review. Statistical analysis could not be performed., Conclusions: Only one RCT was identified in this systematic review. More clinical evidence is necessary to assess the survival rate of EDPT with partial-coverage crowns. This systematic review failed because it did not find scientific evidence to support the use of indirect bonded restorations on EDPT.

Objective: This article provides an updated overview of restorative procedures of endodontically treated teeth., Clinical Considerations: The different techniques and procedures to restore an endodontic treated tooth were considered in the last decades. While they are generally performed using bonding procedures in combination with or without the placement of a post into the root to build up the abutment, there has been a lack of interest in restorative difficulties that can be faced. Failures are represented such as debonding of the post, fracture of the root, decementation, and/or fracture of the restoration, microleakage of the margins. Essentially, the presence of a sufficient failure is considered a key point of a long prognosis. Different clinical factors can directly influence the type of restoration and the longevity of the treatment. The restorative difficulty evaluation system (RDES) is proposed in this article. This new system is composed of eight different clinical factors that are divided into six levels of difficulties. The RDES is composed of 1. Endodontic complexity and outcome, 2. Vertical amount of coronal residual structure and dimension of the pulp chamber, 3. Horizontal amount of coronal residual structure, 4. Restoration marginal seal, 5. Local interdisciplinary conditions, 6. the complexity of the treatment planning, 7. Functional need, 8. Dental wear and esthetic need., Conclusion: This article reviews the RDES and outlines critical steps and tips for clinical success., Clinical Significance: The RDES allows to any clinician to evaluate restorative difficulties when an endodontic treated tooth must be restored, combines clinical aspects that can involve from the single tooth to a full mouth rehabilitation., (© 2022 Wiley Periodicals LLC.)

Background: Patient's illness perception, assessed through the Brief-Illness Perception Questionnaire (Brief-IPQ), plays a decisive role in the treatment effectiveness of a wide range of chronic diseases; nonetheless, evidence is still lacking regarding periodontitis. The aim of the present pre-post quasi-experimental study was to evaluate the change in the Brief-IPQ before and after non-surgical periodontal treatment (NST) and to evaluate its ability to foresee the efficacy of NST., Methods: A total of 126 periodontitis participants starting NST were asked to participate in the study. The nine-item Brief-IPQ together with a full periodontal chart were recorded at baseline and at the 3-month follow up (reevaluation) after NST. Pre-post comparisons of psychometric and periodontal variables were carried out through the Wilcoxon signed-rank test (α = 0.05). A predictive model was built to test the ability of the Brief-IPQ items to foresee the efficacy of NST., Results: NST led to a significant reduction in all periodontal parameters (P < 0.001); the proportion of pockets closed was 64.18%. Although the overall sum score of the Brief-IPQ remained fairly stable (P = 0.0673), significant changes occurred for items seven ("understanding") (P < 0.001) and 8 ("emotional response") (P < 0.05). The best model (R 2  = 0.068, F = 2.15, P = 0.033) obtained from the multivariate linear regression analysis demonstrated that item five ("identity") (β = 2.340, P = 0.017) and item eight ("emotional response") (β = -2.569, P = 0.008) significantly predict the efficacy of NST (i.e., the proportion of pockets closed at reevaluation)., Conclusions: NST significantly ameliorates patient's understanding and emotional burden related to periodontitis. Baseline values of perceived symptoms and emotional response are predictive for the short-term efficacy of NST., (© 2021 American Academy of Periodontology.)

Background: The aim of this randomized controlled trial was to evaluate the capability of an IOS (Intra Oral Scanner) device, used in standardized conditions, to detect margins of abutments prepared with knife-edge finishing line located at three different levels in relation to the gingival sulcus., Methods: sixty abutment teeth for treatment with full crowns were selected and randomly divided in three groups accordingly to the depth of the finishing line: Group A: supragingival margin; Group B: 0.5-1.0 mm into the sulcus; Group C: 1.5-2.0 mm into the sulcus. Temporary crowns were placed for two weeks and then digital impressions (Aadva IOS 100, GC, Japan) were made of each abutment. As controls, analog impressions were taken, poured, and scanned using a laboratory scanner (Aadva lab scanner, GC, Japan). Two standard tessellation language (STL) files were generated for each abutment, subsequently processed, and superimposed by Exocad software (Exocad GmbH, Darmstadt, Germany), applying the "best-fit" algorithm in order to align the scan of the conventional with the digital impressions. The distances between each preparation margin and the adjacent gingival tissue were measured. Four measures were taken, two interproximally and buccally, for a total of six measures of each abutment considering three modes of impressions. The data were statistically evaluated using two-way analysis of variance (ANOVA) for each site and the Bonferroni test., Results: there was no difference between the two kinds of impression in Group A in both sites, in Group B a difference of 0.483 mm and 0.682 mm at interproximal and buccal sites, respectively, and in Group C 0.750 mm and 0.964 mm at interproximal and buccal sites, respectively. The analysis performed on a site level (mesial/distal/vestibular) for the depth of both vertical preparations revealed significant differences ( p < 0.0001). After a post hoc analysis (Bonferroni), vestibular sites of the shallow vertical preparations resulted in significantly lower values compared to the other sites prepared deeply., Conclusions: the results showed that the location of the margin is an important factor in making a precise and complete impression when IOS (Intra Oral Scanner) is used. Moreover, deep preparation into the sulcus is not recommended for IOS (Intra Oral Scanner) impressions.

Background: The aim of this study was to collect long-term restorative and endodontic outcomes of endodontically treated teeth (ETT)., Methods: 298 teeth were included in the study and were recalled up to 18 years with a media of 10.2 years. At baseline, 198 sample teeth (66.44%) showed symptoms and 164 (55%) had periapical radiolucency. The most frequently used obturation techniques were warm gutta-percha in 80% of cases, and by carrier in 20%. A total of 192 ETT were restored by direct resin composite restorations, and 106 posts were luted. Moreover, 75 (25.16%) direct restorations remained as final restorations, 137 single crowns (45.97%), 42 (14.09%) partial adhesive crowns, and 42 (14.09%) abutments of fixed bridges were the final treatments. Descriptive and inferential statistics were performed ( α = 0.05). A Cox regression model was made., Results: results showed success for 92.6% of ETT up to 18 years, 2.68% (8 ETT) showed irreversible failures, and 14 (4.69%) reversible complications. Four ETT (1.34%) failed because of root fracture and the other four (1.34%) because of endodontic complications. Eight ETT (2.69%) showed non-irreversible periodontal complications and the other six (2.01%) prosthodontic complications. Accordingly, with Kaplan-Meier analysis, the survival rate after 18 years was 97.3% (Interval of Confidence (IC) 95.1-98.3). The presence of a short or long (at least 1 mm related to radiographic apex) quality endodontic filling displayed a statistically significant higher risk of complication (hazard ratio (HR) = 17.00 (IC 5.68-56.84). Furthermore, a clinically detectable not precise coronal margins predicts the presence of any clinical complication with a hazard ratio almost seven times higher than endodontically treated teeth with a proper margin (HR = 6.89 (IC 2.03-23.38), while the presence of lucency at the baseline did not affect the risk of complication (HR = 0.575 (IC 0.205-1.61). The presence of post, tooth position in the arch, and the type of it did not show a high-risk rate (HR = 1.85, 1.98, and 2.24, respectively)., Conclusions: a correct filling (at the apex) of root canals combined with proper coronal margins allow obtaining a long-term high success rate in teeth with a periapical lesion at the baseline. The use of a post or not, when its placement is related to the residual amount of the crown, does not change the final outcome of the ETT.

The aim of this study was to investigate the mechanical properties of a fiber hollow endodontic post characterized by the presence of an empty central cylindrical channel extended along the whole length. This particular shape allows clinicians to use the post also as a cementation resin carrier. Ten hollow posts were divided in two groups: the control group (unfilled hollow posts) (Group 0) and hollow posts filled with dual resin cement (Group 1). The samples of both groups were subjected to mechanical and micromorphological analysis by performing a three-point test and SEM observations. In the three-point test, the Group 1 samples exhibited a fracture load of 57.09 ± 5.06 N, a flexural strength of 1323.53 ± 110.09 MPa, and a Young's modulus of 42.87 ± 0.86 GPa. The samples of Group 2 exhibited a fracture load of 38.17 ± 1.7 N, a flexural strength of 908.87 ± 30.98 MPa, and a Young's modulus of 40.33 ± 1.9 GPa. The difference between fracture load, flexural strength, and deflection between the two groups was statistically highly significant ( p < 0.01). Further, the difference between the Young's modulus of the two groups was statistically significant ( p < 0.05). The values obtained are similar to those of other posts available on the market.

Purpose: To compare the sealing effectiveness of four different implant-abutment connections against Staphylococcus aureus (S. aureus). The null hypotheses stated that there was no difference on sealing ability among the implant-abutment connections tested., Methods: Five diverse commercially available dental implants were used to investigate the degree of microleakage at the implant-abutment junction (IAJ): Group 1: Torque Type conical implant with double conic connection - TTc (Winsix); Group 2: Torque Type conical implant with Cone Morse connection - TTcm (Winsix); Group 3: Free Lock connection - K type implant (Winsix); Group 4: Internal double hexagon - OsseoSpeed; Group 5: Internal hexagon - Aadva Implant. Nine implants were tested in each group and one group was used as the negative control (Group 4). The abutments were connected to implants according to manufacturers' recommendations. All procedures involving connection and disconnection of implants were performed in sterile conditions in a laminar flow biological safety cabinet. S. aureus ATCC 6538, a methicillin susceptible reference strain, was chosen for the experiments to test the degree of microleakage. Statistical analysis was performed in order to find significant differences among the five groups regarding sealing capability of the implant-abutment connections tested. The recorded data were statistically analyzed., Results: One implant from Group 4 was excluded from the study because of the growth of a contaminant after 48 hours of incubation in all three wells (i.e. Paenibacillus pabuli, environmental Gram-positive bacteria). Wells A and B (i.e. wells where the samples were passed before being located in the final well C) of all other samples (n = 46) remained sterile over the 72 hours of incubation, indicating the lack of external contamination during implant-abutment connection. Similarly, no bacterial growth was observed in the five negative controls (i.e. one implant for each type), which had been inoculated with sterile saline and processed as the others. Bacterial microleakage was demonstrated with three samples, including one sample of Group 1, one of Group 3 and one of Group 5, in which growth of S. aureus in wells C after 48 hours of incubation was demonstrated (Table 1). No statistically significant difference between groups was noticed (P> 0.05)., Clinical Significance: Within the limitations of the present in vitro model, the results obtained suggest a tendency toward a better sealing capability for conical connections and internal hexagon., Competing Interests: The authors declared no conflict of interest., (Copyright©American Journal of Dentistry.)

Objectives: The concept of Cervical Margin Relocation (CMR) consists on placing a base layer of direct resin composite to elevate supra-gingivally the proximal indirect bonded restorations. The aims of this clinical study were to evaluate 1. Bleeding on Probing (BoP) on posterior indirect restorations with one interproximal margin relocated cervically, and 2. possible correlation between depth of the interproximal margins and BoP., Methods: CMR (Group 1) and shoulder preparations (Group 2) were performed in 35 posterior teeth and evaluated after 12 months (T12). Cavities' margins were placed below the Cemento-Enamel-Junction (CEJ). CMR was applied in one interproximal box-slot preparation using G-Premio Bond, for dentin hybridization, and universal flow resin composite (GC Co. Tokyo, Japan). Pressed lithium disilicate crowns (LS2) (LiSi Press, GC Co. Tokyo, Japan) were made and placed with proprietary luting material. At baseline and after 12 months, clinical surrogate parameters were assessed; and measurements were recorded for the restorative margin position in relation to margo gingivae by probing, and radiographically, the distance from the bone crest was calculated (in mm). Statistical analysis was performed., Results: CMR was associated with statistically significant increased BoP scores compared to shoulder preparation at T12 (53.0% vs. 31.5% per site, respectively) (p=0.10). Gingival Index (GI) and Plaque Index (PI) were not statistically different between both groups. The linear distance between the bone crest and the restorative margin was 2mm in 13 out of 19 experimental sites of Group 1, and 6 out of 11 of Group 2., Conclusions: Higher incidence of BoP can be expected around teeth treated with the concept of CMR and in coincidence with deep margins placed at or closer than 2mm from the bone crest., Clinical Significance: CMR is a clinically sensitive-technique, especially when performed on deep subgingival margins., (Copyright © 2017 Elsevier Ltd. All rights reserved.)