The load capacity of maxillary central incisor with simulated flared root canal restored with different fiber-reinforced composite post and cementation protocols.

Background: This study aimed to evaluate the load capacity of maxillary central incisors with simulated flared root canal restored with different fiber-reinforced composite (FRC) post cemented with either self-adhesive or self-etch resin cement and its mode of fracture. Methods: Sixty-five extracted maxillary incisors were decoronated, its canal was artificially flared and randomly categorized into group tFRC (tapered FRC post) (n = 22), mFRC (multi-FRC post) (n = 21), and DIS-FRC (direct individually shaped-FRC (DIS-FRC) post) (n = 22), which were further subdivided based on cementation resin. The posts were cemented and a standardized resin core was constructed. After thermocycling, the samples were loaded statically and the maximum load was recorded. Results: The load capacity of the maxillary central incisor was influenced by the different FRC post system and not the resin cement (p = 0.289), and no significant interaction was found between them. Group mFRC (522.9N) yielded a significantly higher load capacity compared to DIS-FRC (421.1N). Overall, a 55% favorable fracture pattern was observed, and this was not statistically significant. Conclusion: Within the limitation of the study, it can be concluded that prefabricated FRC posts outperform DIS-FRC posts in terms of the load capacity of a maxillary central incisor with a simulated flared root canal. The cementation methods whether a self-adhesive or self-etch resin cement, was not demonstrated to influence the load capacity of a maxillary central incisor with a flared root canal. There were no significant differences between the favorable and non-favorable fracture when FRC post systems were used to restored a maxillary central incisor with a flared root canal.

Effects of calcium hydroxide intracanal medicament on push-out bond strength of endodontic sealers: A systematic review and meta-analysis.

OBJECTIVE: To investigate the effect of calcium hydroxide intracanal medicament on the push-out bond strength of resin-based and calcium silicate-based endodontic sealers. METHODS: A comprehensive search of was conducted for all relevant in-vitro studies. All randomized controlled in-vitro studies that evaluated the effect of calcium hydroxide on the push-out bond strength of resin-based or calcium silicate-based endodontic sealers were assessed. The variables of interest were extracted, and the risk of the included studies was evaluated. The standardized mean difference was calculated and the significance level was set at p value <0.05. RESULTS: A total of 26 studies were eligible for analysis. There were 45 independent comparison groups and 1009 recruited teeth. The pooled data showed no significant difference in push-out bond strength between calcium hydroxide and control group in the resin-based group (SMD = 0.03; 95% CI = -0.55, 0.60; p = 0.93), and calcium silicate-based group (SMD = 0.02; 95% CI = -0.31, 0.35; p = 0.90). Most of the studies (21 out of 26) were at medium risk of bias and five studies showed a low risk of bias. CONCLUSION: The available evidence suggests that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of the resin- and calcium silicate-based endodontic sealers. CLINICAL SIGNIFICANCE: The results of this meta-analysis suggest that calcium hydroxide used as intracanal medication does not influence the push-out bond strength of resin-based and calcium silicate-based endodontic sealers.

Fracture Resistance of Titanium and Fiber Dental Posts: A Systematic Review and Meta-Analysis.

PURPOSE: The fracture resistance of dental post systems is influenced by the material of the post. The purpose of this systematic review and meta-analysis was to assess if there is a difference in fracture resistance between prefabricated dental titanium posts and fiber posts. METHODS: An online electronic search was performed using the PubMed, Scopus, and Web of Science databases for in vitro studies published from 2010 to 2020 in English. The retrieved eligible studies that compared the fracture resistance of titanium and fiber posts on human teeth were selected. The pooled standardized mean difference (SMD) with a 95% confidence interval was calculated. In addition, the trial sequential analysis (TSA) was performed to test if the available studies are sufficient to make conclusive evidence. RESULTS: Of the 1165 retrieved studies, 17 studies were included in the qualitative analysis, while 16 studies were included in the quantitative analysis. Because of the high heterogeneity among studies, data from 10 studies were pooled and submitted to TSA. A total of 852 teeth were evaluated for fracture of the posts in 27 independent comparison groups. The pooled effect of the residual studies revealed no significant difference between titanium and fiber posts (SMD = -0.12; 95% CI = -0.30, 0.06; p = 0.20). Results of the TSA revealed no conclusive evidence. CONCLUSIONS: The results of the current evidence revealed no significant difference between fiber and titanium posts. The evidence is insufficient, and more standardized in vitro studies are required.

Quality and readability of web-based Arabic health information on periodontal disease.

BACKGROUND: Currently, the Internet seems to be a helpful tool for obtaining information about everything that we think about, including diseases, their prevention and treatment approaches. However, doubts exist regarding the quality and readability of such information. This study sought to assess the quality and readability of web-based Arabic information on periodontal disease. METHODS: In this infodemiological study, the Google, Yahoo!, and Bing search engines were searched using specific Arabic terms on periodontal disease. The first 100 consecutive websites from each engine were obtained. The eligible websites were categorized as commercial, health/professional, journalism, and other. The following tools were applied to assess the quality of the information on the included websites: the Health on the Net Foundation Code of Conduct (HONcode), the Journal of the American Medical Association (JAMA) benchmarks, and the DISCERN tool. The readability was assessed using an online readability tool. RESULTS: Of the 300 websites, 89 were eligible for quality and readability analyses. Only two websites (2.3%) were HONcode certified. Based on the DISCERN tool, 43 (48.3%) websites had low scores. The mean score of the JAMA benchmarks was 1.6 ± 1.0, but only 3 (3.4%) websites achieved "yes" responses for all four JAMA criteria. Based on the DISCERN tool, health/professional websites revealed the highest quality of information compared to other website categories. Most of the health/professional websites revealed moderate-quality information, while 55% of the commercial websites, 66% of journalism websites, and 43% of other websites showed poor quality information. Regarding readability, most of the analyzed websites presented simple and readable written content. CONCLUSIONS: Aside from readable content, Arabic health information on the analyzed websites on periodontal disease is below the required level of quality.

Push-out Bond Strength of Two Types of Dental Post Luted with Two Types of Cement at Two Different Root Levels.

OBJECTIVE: Endodontically treated teeth may require posts for retaining the core and replacing the coronal structures that have been lost. The objective of this study was to evaluate and compare the push-out bond strength between different types of post cemented with different types of luting cement at different types of root level. MATERIALS AND METHODS: In this in-vitro study, a total of 48 single-rooted permanent human teeth were decoronated, and the roots were treated endodontically. Following post space preparation, the sample was divided into four groups (n= 12 each) based on the types of post and cement. Two different types of post [GC everStick®POST (ES) and Parapost® Fiber LuxTM (PF)], and two different types of cement [G-CEMTM (G), and RelyXTM Unicem (R)] were used according to the manufacturer's instructions. All roots were sectioned at the coronal and middle thirds with a thickness of 3±0.1mm. The Push-out bond strength (PBS) test was performed using a universal testing machine at a cross-head speed of 0.5mm/ min. The bond strength values were recorded, and the data were analyzed using the SPSS program. Apart from descriptive statistics, three-way ANOVA was used for the interaction of the independent variables (post, cement, and root level). For differences between the groups, the Mann-Whitney U test was used. A P-value of less than 0.05 was considered significant for all analyses. RESULTS: Push-out bond strength of samples at the middle level (11.38±10.31 MPa), with PF posts (11.18±9.98 MPa), and of those luted with RelyXTM Unicem cement (13.26±8.73 MPa) was higher than that of their counterparts. The PBS means of RelyXTM Unicem cement at both root levels were much higher than PBS means of G-CEMTM cement. Three-way ANOVA test revealed a significant effect for each variable with a higher effect of cement (Sum of Squares= 1310.690; P< 0.001). No significant difference (P= 0.153) was found between the coronal and middle parts and between ES and PF posts (P= 0.058). However, a highly significant difference (P< 0.001) was found between RelyXTM Unicem and G-CEMTM cements. CONCLUSION: The type of cement had a significant effect on push-out bond strength with RelyXTM Unicem which had higher values than G-CEMTM. However, the type of post and root level had no significant effect on PBS, although Parapost® Fiber LuxTM and middle root level had higher values than their counterparts.

Perception of orofacial appearance among laypersons with diverse social and demographic status.

BACKGROUND: The perception of dentofacial esthetics differs considerably between patients and dentists. Patient's expectations regarding his/her esthetics are important and should be assessed ahead of any planning of esthetic treatment. The aim of this study was to explore the differences in perception of orofacial appearance by laypersons with different social and demographic status. MATERIALS AND METHODS: Self-administered questionnaires were distributed to 400 subjects. The questionnaire comprised three parts; the first part addressed the demographic variables. The second part queried about dental prosthesis, orthognathic or plastic surgery, and/or ongoing or previous orthodontic treatment. The third part included the Arabic version of the-8-item Orofacial Esthetic Scale (OES-Ar) whose responses were scored in the 5-point Likert scale. These scores were compared by different grouping factors (age, gender, marital status, and education) using non-parametric Mann-Whitney U and Kruskal Willis tests with 95% confidence interval (α > 0.05). RESULTS: A total of 268 questionnaires were eligible for analysis, representing 67% response rate. The satisfaction with facial profile appearance was the highest (4.0±1.1) followed by facial appearance (3.9±1.1), while the color of teeth was the least satisfying item (3.1±1.3). No significant differences were found between age groups for the mean summary score as well as for each item independently. No significant difference was found between both sexes except for the last item "overall impression". Married subjects rated one item (alignment of teeth) better than their counterparts. Positive perception of orofacial appearance increased significantly with the increase of education level, the perception of the oral health status, and the perception of the general health status. CONCLUSION: Good oral health and/or high education level are significant determinants of more positive perception of orofacial esthetic appearance. Patients with these characteristics might be more concerned about their orofacial appearance, and this should be taken into consideration before planning any esthetic restorative dental treatment.

The association between Epstein-Barr virus and oral lichen planus: A systematic review and meta-analysis.

BACKGROUND: Oral lichen planus (OLP) is a relatively common inflammatory disease, with unclear etiology. A number of studies have linked Epstein-Barr virus (EBV) with OLP. The present systematic review and meta-analysis aimed to evaluate the available evidence regarding the potential association between EBV and OLP. METHODS: Online databases (PubMed, Scopus, Web of Science, ProQuest, and Google Scholar) were searched from date of inception till May 2020. Studies were included if they met the following criteria: 1) observational studies that assessed the relationship between EBV and OLP, 2) the study comprised OLP patients and control subjects, 3) diagnosis of OLP was confirmed histopathologically, and 4) articles were in English. Studies without control groups, experimental studies, case reports, and reviews were excluded. The fixed-effects model was performed for meta-analyses using RevMan 5.3 software. RESULTS: A total of 10 studies comprising 386 OLP cases and 304 controls were included. Of these, only 8 studies were eligible for the meta-analysis. The results of the quality assessment showed that only 2 studies were of high quality, while the remaining studies were of moderate quality. The results of the pooled eight studies revealed a significant positive association between EBV and OLP (OR = 4.41, 95% CI: [2.74, 7.11], P < .0001). CONCLUSION: The results of the present systematic review suggest that EBV infection is statistically associated with increased risk of OLP. However, these results are preliminary, and high-quality, large-scale studies are warranted to further explore the potential role of EBV in the pathogenesis of OLP.

Happiness among dentists: a multi-scale, multi-national study from 21 countries.

OBJECTIVES: The extent to which dentists are happy with their profession and their life has not been well studied. The present study aimed to explore the level of happiness, satisfaction with life and psychological well-being among a sample of dental professionals from 21 countries. MATERIALS AND METHODS: The sample comprised 2,200 dentists from 21 countries. Three scales - Subjective Happiness Scale (SHS), Satisfaction With Life Scale (SWLS), and Affect Balance Scale (ABS) - were used to measure the subjective responses. Data related to demographic and social characteristics were recorded. Mann-Whitney and Kruskal-Wallis tests were used as appropriate. Scales were correlated, and multiple linear regression analyses were employed to identify the independent determinants of SHS, SWLS and ABS. Data were analysed using the SPSS software program; a value of P <0.05 was considered significant. RESULTS: The overall mean scores of SHS, SWLS and ABS were 18.53 ± 5.06, 23.06 ± 6.25 and 1.26 ± 2.40, respectively, with significant differences found across countries: dentists working in Croatia, Peru and Serbia recorded the highest scores, unlike dentists practicing in Yemen, Syria, and Iraq, who recorded the lowest scores. There were significant, moderately positive correlations between the various scales: SHS and SWLS: r = 0.535, P < 0.001; SHS and ABS: r = 0.58, P < 0.001; and SWLS and ABS: r = 0.533, P < 0.001. Country of practice, age, qualification and monthly income were the significant independent predictors of SHS, SWLS and ABS. CONCLUSION: Country of residence and social characteristics were associated with dentists' responses regarding their feelings and subjective well-being.

Quality and Readability of Web-based Arabic Health Information on Denture Hygiene: An Infodemiology Study.

AIM: This study aimed to assess the quality and readability of the available health information on the net regarding denture hygiene. MATERIALS AND METHODS: Three search engines (Google, Yahoo!, and Bing) were searched. The first 20 consecutive websites from each engine were obtained and checked for eligibility. For the quality of the websites, the Health on the Net Foundation Code of Conduct (HONcode), the DISCERN tool, the Journal of the American Medical Association (JAMA) Benchmarks, and Google PageRank were used for the assessment of the included websites. For readability, an online web tool was used, including well-known analyzing indices [Flesch Kincaid grade level (FKGL), Simple Measure of Gobbledygook (SMOG), and Flesch Reading Ease (FRE)]. The acceptable readability level was set to be ≥80.0 for the FRE and <7 for the FKGL and SMOG. The data were presented in frequencies and percentages. RESULTS: Out of the 60 screened websites, 14 websites were eligible for analysis. There was only one (7.1%) website that had the HONcode seal. The mean score of all websites based on the DISCERN tool was 29.6 ± 12.1, with no website achieved the high score (≥65). Only one (7.1%) website scored >5 based on Google PageRank. Regarding JAMA benchmarks, all websites achieved a mean score of 2.57 ± 1.1. The mean grade level based on the FKGL was 8.4 ± 6.3. All websites had a score of <7 according to the SMOG index. The mean score of the readability ease index was 90.5 ± 16.4. CONCLUSION: Most of the dental health information on denture hygiene available on the Arabic websites did not have the required level of quality, regardless of being readable and comprehensible by most of the general people. CLINICAL SIGNIFICANCE: Directing the patients to the appropriate websites related to their cases is the responsibility of the dentists.

Marginal Gap Evaluation of Metal Onlays and Resin Nanoceramic Computer-Aided Design and Computer-Aided Manufacturing Blocks Onlays.

OBJECTIVE: This study was carried out to assess and compare the marginal gap of conventionally used metal onlays and new resin nanoceramic (RNC) (Lava Ultimate block) onlays. MATERIALS AND METHODS: This is an in vitro study using two extracted sound human mandibular molars. One tooth was prepared to receive the metal onlays and another one for the RNC onlays which were fabricated using the computer-aided design and computer-aided manufacturing (CAD/CAM) technology. Twelve metals and 12 ceramic onlays were fabricated before they were placed at their respective preparation and examined under the Leica stereomicroscope, M125C (Leica Microsystems, Wetzlar, Germany) for a marginal analysis. The gap width was measured at 10 predefined landmarks which included 3 points on the buccal and lingual surfaces each and 2 points each on the mesial and distal surfaces, respectively. STATISTICAL ANALYSIS: Mann-Whitney post hoc test was used for statistical analysis (P ≤ 0.05). RESULTS: Overall, the RNC onlays showed significant lower marginal gap with the exception of the landmarks 5 and 6 (on distolingual) and no significant difference at landmark 7 (on midlingual). It was observed that the marginal gap were all within the clinically acceptable limit of 120 µm. CONCLUSIONS: Based on the results obtained, it can be concluded that the RNC CAD/CAM onlays are a promising alternative to the metal onlays.

Evaluation of Microleakage Between Different Post and Core Systems Under Gradual Loading: an In-Vitro Study.

OBJECTIVE: This study aimed to compare the difference in marginal dye penetration between everStick, Parapost XP, Parapost fiber white and control groups under gradual loading. MATERIALS AND METHODS: Sixty-eight human maxillary permanent incisors were divided into four groups. Each specimen was endodontically treated with step-back technique and prepared for each post system according to experimental groups, subsequently cemented in the canal. Composite resin cores were built and laboratory fabricated metal crowns were cemented. All specimens except those in the control group were subjected to thermal cycling. All groups were subjected to gradual loading from 0N-50N for 100 cycles. Specimens were sectioned transversely and the depths of dye penetration along the post were measured. Data were entered in SPSS ver. 22 and analyzed using two-way ANOVA test. RESULTS: There was no significant difference in marginal dye penetration between each group (p-value>0.05). However, there was a significant difference in percentage of marginal dye penetration between all groups (p-value<0.05); post-hoc comparison showed significant difference between Fiber White and Control groups (p-value=0.009). CONCLUSION: All the groups showed dye penetration but the percentage was significant only between Parapost Fiber White and the control groups.

Surface Coating of Gypsum-Based Molds for Maxillofacial Prosthetic Silicone Elastomeric Material: Evaluating Different Microbial Adhesion.

PURPOSE: To compare the adhesion of three microorganisms on modified and unmodified silicone elastomer surfaces with different surface roughnesses and porosities. MATERIALS AND METHODS: Candida albicans, Streptococcus mutans, and Staphylococcus aureus were incubated with modified and unmodified silicone groups (N = 35) for 30 days at 37°C. The counts of viable microorganisms in the accumulating biofilm layer were determined and converted to cfu/cm2 unit surface area. A scanning electron microscope (SEM) was used to evaluate the microbial adhesion. Statistical analysis was performed using t-test, one-way ANOVA, and post hoc tests as indicated. RESULTS: Significant differences in microbial adhesion were observed between modified and unmodified silicone elastomers after the cells were incubated for 30 days (p < 0.001). SEM showed evident differences in microbial adhesion on modified silicone elastomer compared with unmodified silicone elastomer. CONCLUSIONS: Surface modification of silicone elastomer yielding a smoother and less porous surface showed lower adhesion of different microorganisms than observed on unmodified surfaces.

Intracanal Adaptation of a Fiber Reinforced Post System as Compared to a Cast Post-and-Core.

BACKGROUND: The purpose of this study was to compare the adaptation of fiber reinforced composite post system and cast post-and-core. METHODS: 17 extracted human permanent maxillary central incisors were endodontically treated following the standard protocol. 17 fiber reinforced composite post had been fabricated and adapted to the prepared parallel root canals. A light body poly vinyl siloxane (EXAMIX NDS, Japan) impression material was inserted into the root canals followed by the post. A digital scale was used to measure the weight of the remaining material that filled the gap between the post and the canal wall. The adaptation was indicated by the weight difference before and after impression material insertion. The same procedures were repeated with 17 cast post-and-core in the same teeth specimens. RESULT: The mean difference for the weight of the material within the group was statistically significant (P-value <0.001) with the value of 6.1mg(± 2.7mg) for cast metal post and 6.4mg(± 2.7mg) for fiber reinforced composite post. However, the mean difference was not statistically significant when compared with both materials (P-value>0.05). CONCLUSIONS: Both cast post-and-core and fiber reinforced composite post systems showed similar adaptation to the canal.

Combined Mandibular Guidance Therapy in the Management of a Hemimandibulectomy Patient.

This case history report describes two different devices, maxillary ramp prostheses (MRP) and mandibular guide flange prostheses (MGFP), prescribed for managing a hemimandibulectomy patient's deviated mandible. The patient was given muscle reprogramming exercises with coordinated use of both guidance prostheses for 2 months, leading to improvements in both postsurgical mandibular deviation and occlusal equilibration. A successful intercuspal position was eventually accomplished through the use of the combination therapy. MRP and MGFP can be a useful approach to avoid mandibular deviation and compromised function following a partial mandibular resection.

Shear bond strength of computer-aided design and computer-aided manufacturing feldspathic and nano resin ceramics blocks cemented with three different generations of resin cement.

AIM: To evaluate the shear bond strength between the dentin substrate and computer-aided design and computer-aided manufacturing feldspathic ceramic and nano resin ceramics blocks cemented with resin cement. MATERIALS AND METHODS: Sixty cuboidal blocks (5 mm × 5 mm × 5 mm) were fabricated in equal numbers from feldspathic ceramic CEREC(®) Blocs PC and nano resin ceramic Lava™ Ultimate, and randomly divided into six groups (n = 10). Each block was cemented to the dentin of 60 extracted human premolar using Variolink(®) II/Syntac Classic (multi-steps etch-and-rinse adhesive bonding), NX3 Nexus(®) (two-steps etch-and-rinse adhesive bonding) and RelyX™ U200 self-adhesive cement. All specimens were thermocycled, and shear bond strength testing was done using the universal testing machine at a crosshead speed of 1.0 mm/min. Data were analyzed using one-way ANOVA. RESULTS: Combination of CEREC(®) Blocs PC and Variolink(®) II showed the highest mean shear bond strength (8.71 Mpa), while the lowest of 2.06 Mpa were observed in Lava™ Ultimate and RelyX™ U200. There was no significant difference in the mean shear bond strength between different blocks. CONCLUSION: Variolink(®) II cement using multi-steps etch-and-rinse adhesive bonding provided a higher shear bond strength than the self-adhesive cement RelyX U200. The shear bond strength was not affected by the type of blocks used.

Surface Coating of Gypsum-Based Molds for Maxillofacial Prosthetic Silicone Elastomeric Material: The Surface Topography.

PURPOSE: This study aimed to compare the surface roughness of maxillofacial silicone elastomers fabricated in noncoated and coated gypsum materials. This study was also conducted to characterize the silicone elastomer specimens after surfaces were modified. MATERIALS AND METHODS: A gypsum mold was coated with clear acrylic spray. The coated mold was then used to produce modified silicone experimental specimens (n = 35). The surface roughness of the modified silicone elastomers was compared with that of the control specimens, which were prepared by conventional flasking methods (n = 35). An atomic force microscope (AFM) was used for surface roughness measurement of silicone elastomer (unmodified and modified), and a scanning electron microscope (SEM) was used to evaluate the topographic conditions of coated and noncoated gypsum and silicone elastomer specimens (unmodified and modified) groups. After the gypsum molds were characterized, the fabricated silicone elastomers molded on noncoated and coated gypsum materials were evaluated further. Energy-dispersive X-ray spectroscopy (EDX) analysis of gypsum materials (noncoated and coated) and silicone elastomer specimens (unmodified and modified) was performed to evaluate the elemental changes after coating was conducted. Independent t test was used to analyze the differences in the surface roughness of unmodified and modified silicone at a significance level of p < 0.05. RESULTS: Roughness was significantly reduced in the silicone elastomers processed against coated gypsum materials (p < 0.001). The AFM and SEM analysis results showed evident differences in surface smoothness. EDX data further revealed the presence of the desired chemical components on the surface layer of unmodified and modified silicone elastomers. CONCLUSIONS: Silicone elastomers with lower surface roughness of maxillofacial prostheses can be obtained simply by coating a gypsum mold.

An agar diffusion study comparing the antimicrobial activity of Nanoseal with some other endodontic sealers.

The aim of this study was to evaluate the antimicrobial activity of a new experimental nano-hydroxyapatite epoxy resin-based sealer (Nanoseal) with several other commercially available sealers; AH26, Tubliseal, Sealapex and Roekoseal against Enterococcus faecalis, Pseudomonas aeruginosa, Streptococcus mutans, Streptococcus sobrinus and Escherichia coli for up to 7 days. Agar diffusion was used in this study. Fifty Muller-Hinton agar plates were prepared and divided into five experimental groups (n = 10), for each micro-organism. Another 10 agar plates were used as positive and negative controls. Endodontic sealers were tested against each micro-organism. Inhibition zones produced were recorded. The results of this study showed that all test materials exhibited inhibition zones towards the tested micro-organisms for 7 days except for Roekoseal, which showed no inhibition zones. Nanoseal and AH26 exhibited similar zones of inhibition. Significant difference was found between Nanoseal and the other tested sealers (P < 0.001).