Knowledge of undergraduate and postgraduate dental students about managing traumatic dental injuries based on the 2020 International Association of Dental Traumatology guidelines: A online survey of 10 dental schools from 10 countries.

BACKGROUND/AIM: The knowledge of dental students about managing traumatic dental injuries (TDIs) may not be uniform, depending on global location and dental education. The aim of this study was to evaluate the level of knowledge of undergraduate and postgraduate students specializing in endodontics and pediatric dentistry at 10 dental schools in 10 countries about the 2020 International Association of Dental Traumatology (IADT) guidelines regarding the management of TDIs. MATERIALS & METHODS: A previously published questionnaire was used in the current survey. It was an online survey with 12 questions regarding the management of TDIs and some additional questions regarding sociodemographic and professional profiles of the participants were added. The survey was distributed to final-year undergraduate students and postgraduate students in pediatric dentistry and endodontics from 10 dental schools. Simple frequency distributions and descriptive statistics were predominantly used to describe the data. Differences in the median percentage scores among the student categories were assessed using the Kruskal-Wallis test followed by Dwass-Steel-Critchlow-Fligner pairwise comparisons. RESULTS: A total of 347 undergraduates, 126 postgraduates in endodontics, and 72 postgraduates in pediatric dentistry from 10 dental schools participated in this survey. The postgraduates had a significantly higher percentage score for correct responses compared with the undergraduates. No significant difference was observed between the endodontic and pediatric dentistry postgraduates. CONCLUSION: The knowledge possessed by undergraduate and postgraduate students concerning the IADT-recommended management of TDIs varied across the globe and some aspects were found to be deficient. This study emphasizes the critical importance of reassessing the teaching and learning activities pertaining to the management of TDIs.

Prevalence of apical periodontitis in patients with autoimmune diseases: A case-control study.

AIM: The purpose of this case-control study was to compare the prevalence of apical periodontitis (AP) in patients affected by autoimmune disorders (AD) (inflammatory bowel disease [IBD], rheumatoid arthritis [RA] and psoriasis [Ps]) with the prevalence of AP in subjects without AD. The prevalences of AP in patients taking biologic medications, conventional medications and no medication were also compared. METHODOLOGY: Eighty-nine patients (2145 teeth) with AD were investigated and the control group included 89 patients (2329 teeth) with no systemic diseases. Full dental panoramic tomograms were used to determine the periapical status of the teeth. Additional variables investigated included patient's socio-demographic characteristics, medications taken by AD patients, the decayed, missing and filled teeth (DMFT) index. The chi-square test and logistic regression analysis were used to evaluate the correlation between AD and AP. p-Values lower than .05 were considered to be statistically significant. RESULTS: The prevalence of AP was 89.9% in AD patients and 74.2% in control subjects (odds ratio [OR] = 3.75, p = .015). The DMFT score was found to be significantly higher in the AD group (p = .004). Patients with RA had the highest risk of being affected by AP, whereas those with IBD had the lowest risk. Multiple binary logistic regression analysis indicated that the teeth of AD patients who were not taking any medication or were being treated with biologic disease-modifying anti-rheumatic drugs (bDMARDs) had a higher risk of being affected by AP than did the teeth of the control subjects (OR = 1.42 and OR = 2.03, respectively; p = .010). The teeth of patients taking conventional DMARDs (cDMARDs) were less affected by AP compared with those of patients taking bDMARDs. CONCLUSIONS: Patients with AD, whether treated or not with biologic medications, showed a higher prevalence of AP than did those in the control group. The DMFT index score, which was higher in AD patients compared with controls was identified as a significant predictor of AP prevalence.

Successful endodontic treatment reduces serum levels of cardiovascular disease risk biomarkers-high-sensitivity C-reactive protein, asymmetric dimethylarginine, and matrix metalloprotease-2.

AIM: To investigate serum biomarkers of inflammation 2 years following non-surgical root canal re-treatment (Re-RCT) and peri-apical surgery (PS). The results were correlated with signs and symptoms, treatment outcome, metabolic syndrome factors, infection with severe acute respiratory syndrome coronavirus 2 SARS-CoV-2 (COVID-19) infection and COVID-19 vaccination. METHODOLOGY: Subjects from our previous study were recalled for 2 years post-treatment follow-up. Changes to the patient's history (medical, dental, social) were noted. Periapical health of the treated teeth was examined both clinically and radiographically. Blood pressure, fasting HbA1C and low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides and total cholesterol (TC) levels were measured. Serum inflammatory marker levels were assayed using a Bio-Rad Bio-Plex 200 analyser and values at different time points within the same group were compared using a Wilcoxon signed-rank test and differences between groups with a Mann-Whitney test. Linear associations were tested using Pearson's correlations. RESULTS: The recall percentage at 2 years was 56.9% (n = 37), with a 100% radiographic success rate using periapical radiographs. In total, 21 cases (56.8%) were completely healed, and 16 cases (43.2%) were healing. Higher matrix metalloprotease 2 (MMP2) levels were present in the healing group compared to the healed group. Serum levels of high-sensitivity C-reactive protein (hs-CRP), asymmetric dimethylarginine (ADMA) and MMP-2 were significantly reduced (p ≤ .001) whereas other biomarkers showed significant increases at 2 year compared to pre-operative levels, while FGF-23 and ICAM-1 were not significantly increased. HbA1C (p = .015), TC (p = .003), LDL (p = .003) and HDL (p = .003) reduced significantly at 2 years post-treatment compared to their preoperative levels. COVID infection showed a significant association with MMP-9 (p = .048). CONCLUSIONS: hs-CRP, ADMA and MMP-2 can be regarded as prognostic biomarkers of successful Re-RCT and PS as they reduced at 2 year recall in cases which showed evidence of clinical and radiographic success. The successful treatment of chronic apical periodontitis is correlated with improvements in metabolic syndrome indicators, better glycemic control, and reduction at 2 year of some systemic inflammatory markers which are related to risks of cardiovascular disease events.

The role of systemic statins in the inception and healing of apical periodontitis: a systematic review.

OBJECTIVES: Statins are a category of medications widely used to reduce plasma LDL-cholesterol levels, that also possess antibacterial, anti-inflammatory, and immunomodulatory action. The aim of this systematic review was to explore the effects of systemic statins therapy on the development and treatment of apical periodontitis (AP) on humans and animals. MATERIAL AND METHODS: Three electronic databases (PubMed, Web of Science, and Scopus) and grey literature were searched from their inception until February, 20 2023 (PROSPERO CRD42021246231). For the quality assessment and risk of bias, different guidelines were used according to the typology of the studies considered (Animal Research Reporting of In Vivo Experiments, Newcastle-Ottawa Quality Assessment Form for Cohort Studies, Systematic Review Centre for Laboratory animal Experimentation Risk of Bias tool and Tool to assess risk of bias in cohort studies of CLARITY Group). RESULTS: Seven hundred eleven records were screened, and six articles were included for this qualitative review. The eligible studies showed a moderate overall quality and risk of bias. Human patients in treatment with statins exhibited a higher healing rate of AP following root canal treatment. In experimental animal models, statins had a beneficial effect on the development of AP. CONCLUSIONS: Despite the limited number of studies and considering that most of them are on animals, our findings suggest that systemically administered statins make a positive contribution to prevent the development and help healing of AP. CLINICAL RELEVANCE: There is an increased evidence that a pharmacologic adjunct to endodontic treatment may be considered to enhance healing of AP. Among other medications, statins seem to have a positive impact on the disease.

The impact of apical periodontitis, non-surgical root canal retreatment and periapical surgery on serum inflammatory biomarkers.

AIM: The aim of the study was to measure serum levels of molecular markers of inflammation in patients undergoing non-surgical root canal retreatment (Re-RCT) and periapical surgery (PS) for the treatment of apical periodontitis and to establish if such levels are influenced by the size of apical radiolucencies at baseline and by the treatment outcome. METHODOLOGY: A total of 115 participants were recruited (n = 50 Controls, n = 35 Re-RCT, n = 30 PS). Preoperative periapical radiographs and cone beam CT (CBCT) scans of teeth were taken. Blood was collected from treatment groups at baseline, 3-, 6-, and 12-month post-treatment and from controls at baseline and 12 months. Serum levels of IL-1ß, IL-6, IL-8, TNF-α, Pentraxin 3, ICAM-1, VCAM-1, hs-CRP, FGF-23, MMP-2, MMP-8, MMP-9, C3 and ADMA were analysed using multiplex immunoassay and enzyme-linked immunosorbent assay. Different time points within the same group were compared using Wilcoxon signed-rank test, and differences between groups were analysed using the Mann-Whitney test. Non-linear association between different factors was assessed using Spearman's correlation. RESULTS: Preoperative serum levels of FGF-23, IL-1ß, hs-CRP and ADMA were significantly higher in the diseased groups compared with controls (p < .001; p = .008; p < .001; p = .013, respectively). The preoperative size of the radiolucency was associated with increased levels of FGF-23, IL-1ß and IL-6. At 3-months following treatment, IL-1ß, IL-8, hs-CRP, C3, MMP-2 and MMP-9 levels increased compared with baseline in treatment groups. IL-1ß and IL-8 further increased at 6 months, whereas FGF-23, hs-CRP, C3, MMP2 and MMP-9 decreased. One-year post-treatment, FGF-23, pentraxin-3 and ADMA were significantly reduced below baseline levels. At the 1-year review, CBCT revealed that 25.9% of treated cases completely healed, while 63% were healing, and 11.1% failed. Treatment outcome was found to be influenced by preoperative levels of ADMA and IL-8 levels at 6 months. CONCLUSIONS: Both symptomatic and asymptomatic apical periodontitis (AP) can contribute to increased levels of molecular markers of inflammation. A further transient inflammatory markers rise after root canal retreatment and apical surgery were demonstrated. Successful endodontic treatment and periapical surgery result in a long-term reduction in inflammatory marker levels.

Present status and future directions: The restoration of root filled teeth.

This narrative review will focus on a number of contemporary considerations relating to the restoration of root filled teeth and future directions for research. Clinicians are now more than ever, aware of the interdependence of the endodontic and restorative aspects of managing root filled teeth, and how these aspects of treatment are fundamental to obtaining the best long-term survival. To obtain the optimal outcomes for patients, clinicians carrying out endodontic treatment should have a vested interest in the restorative phase of the treatment process, as well as an appreciation for the structural and biomechanical effects of endodontic-restorative procedures on restoration and tooth longevity. Furthermore, the currently available research, largely lacks appreciation of occlusal factors in the longevity of root filled teeth, despite surrogate outcomes demonstrating the considerable influence this variable has. Controversies regarding the clinical relevance of minimally invasive endodontic and restorative concepts are largely unanswered with respect to clinical data, and it is therefore, all too easy to dismiss these ideas due to the lack of scientific evidence. However, conceptually, minimally invasive endodontic-restorative philosophies appear to be valid, and therefore, in the pursuit of improved clinical outcomes, it is important that the efficacies of these treatment protocols are determined. Alongside an increased awareness of the preservation of tooth structure, developments in adhesive bonding, ceramic materials and the inevitable integration of digital dentistry, there is also a need to evaluate the efficacy of new treatment philosophies and techniques with well-designed prospective clinical studies.

The impact of an enhanced infection control protocol on molar root canal treatment outcome - a randomized clinical trial.

AIM: To evaluate the effect of an enhanced infection control protocol on root canal treatment outcomes and on microbial load within root canals after chemomechanical preparation. METHODOLOGY: A total of 144 molar teeth from 139 healthy patients receiving primary root canal treatment were block randomized to a standard protocol (StP) or an enhanced infection control protocol (EnP). Both treatment arms adhered to current best practice recommendations, while the EnP comprised additional steps that included replacing rubber dams, gloves, files, all instruments and surface barriers at the time of canal filling to reduce the chances of iatrogenic contamination. Patients and radiographic examiners were blinded to the protocol used. Intracanal microbial samples were taken at baseline (S1) and after completion of chemomechanical preparation (S2). Microbial 16S rDNA copy numbers were enumerated by quantitative polymerase chain reaction (qPCR). Cone beam computed tomography (CBCT) scans were taken before treatment and at one-year follow-up. The outcome was assessed clinically and radiographically using CBCT by logistic regression modelling. RESULTS: At one-year follow-up, 115 teeth were analysed (54 in StP and 61 in EnP). The percentage of favourable outcomes assessed by CBCT was 85.2% in the EnP and 66.7% in the StP. The odds of 12-month success was three times higher in the EnP group compared with the StP group (OR=2.89; p=0.022, CI: 1.17 - 7.15). The median bacterial reads were reduced from 8.1×103 in S1 samples to 3.5×103 in the StP group and from 8.6×103 to 1.3×103 in the EnP group. The enhanced protocol significantly reduced bacterial counts in pre-canal filling samples when compared to the standard protocol (p=0.009). CONCLUSIONS: The implementation of a facile, enhanced infection control protocol in primary root canal treatment resulted in less detectable bacterial DNA before canal filling and significantly more successful outcomes at one year.

European Society of Endodontology position statement: The restoration of root filled teeth.

This position statement on the restoration of root filled teeth represents the consensus of an expert committee, convened by the European Society of Endodontology (ESE). Current clinical and scientific evidence, as well as the expertise of the committee, have been used to develop this statement. The aim is to provide clinicians with evidence-based principles for decision-making on the choice of restoration following the completion of root canal treatment. By discussing the evidence in relation to key topics regarding post-endodontic restoration, a series of clinical recommendations are made. The scientific basis of the recommendations made in this paper can be found in a recently published review article (Bhuva et al. 2021, International Endodontic Journal, https://doi.org/10.1111/iej.13438). It is the intention of the committee to update this statement as further evidence emerges.

Schneiderian membrane thickness variation following endodontic procedures: a retrospective cone beam computed tomography study.

BACKGROUND: To assess the change of the Schneider membrane thickness measured by CBCT before and after root canal treatment, retreatment and pulp capping procedures. METHODS: This retrospective study was conducted on CBCT scans of a patient population of Guy's Hospital NHS Foundation Trust, London. Three groups of patients were studied: Group 1 consisted of patients referred for primary endodontic treatment; Group 2 for endodontic retreatment; Group 3 for indirect pulp capping procedures (serving as a control group). Follow up scans were carried out 1 year after treatment. Measurements were carried out on CBCT scans and data were analysed statistically by Wilcoxon Signed Rank Test. Linear regression was used to assess predictive parameters for membrane thickness. RESULTS: A statistically significant reduction of the Schneider membrane thickness was observed one year after endodontic treatment and retreatment (P < 0.05) but no significant reduction was observed after pulp capping procedures. Linear regression showed that age and gender were significant predictors influencing the Schneider membrane thickness. CONCLUSIONS: Within the limitations of this retrospective study, following root canal treatment and re-treatment a Schneiderian membrane thickness reduction occurred at 1-year follow-up. The removal of odontogenic infection following endodontic treatment may help reducing the thickness of the Schneider membrane.

Evaluation of the efficacy of calcium silicate vs. glass ionomer cement indirect pulp capping and restoration assessment criteria: a randomised controlled clinical trial-2-year results.

OBJECTIVES: Assess calcium silicate cement (Biodentine™) vs. glass ionomer cement (Fuji IX™, control) as indirect pulp capping (IPC) materials in patients with reversible pulpitis after a 2-year follow-up. Evaluate the integrity of the overlying resin composite restorations using modified USPHS criteria and FDI criteria. Investigate the sensitivity of the modified USPHS criteria compared to the FDI criteria in the assessment of the restorations. MATERIALS AND METHODS: Seventy-two restorations (36 Biodentine™, 36 Fuji IX™) were placed randomly in 53 patients. Periapical radiographs were taken at pre-treatment (T0), 12-month (T12), and 24-month (T24) review. Restorations were assessed using the modified USPHS and FDI criteria at T12 and T24. RESULTS: At 24 months, 15 teeth had failed to maintain vitality (6 Biodentine™, 9 Fuji IX™). Clinical success rate of IPC for both materials was 72% and is related to the intensity of reversible pulpitis symptoms. No difference was found between T12 and T24 in the periapical (PA) radiographs and in the integrity of the resin composite restorations overlying Biodentine™ compared to Fuji IX™. There was no difference in the efficacy of the USPHS criteria compared to the FDI criteria in the assessment of the resin composite restorations. CONCLUSIONS: Biodentine™ and Fuji IX™ were clinically effective when used as IPC materials in teeth with reversible pulpitis at T24. Resin composite restorations overlying both materials performed well at T24. Using the USPHS or FDI criteria is equally efficient at T24; however, longer term follow-up is needed to establish whether there are sensitivity differences between these assessment criteria. CLINICAL SIGNIFICANCE: Teeth with deep carious lesions approaching the pulp and with signs of reversible pulpitis can be treated successfully by indirect pulp capping using either Biodentine™ or Fuji IX™. Using the USPHS or FDI criteria to assess restorations is equally effective at 2 years. TRIAL REGISTRATION: NCT02201641.

Assessment of residual coronal tooth structure postendodontic cavity preparation using digital dental impressions and micro-computed tomography.

OBJECTIVES: To evaluate the in vitro accuracy of digital impressions for three-dimensional (3D) volumetric measurement of residual coronal tooth structure postendodontic cavity preparation, with reference to micro-computed tomography (µCT). METHODS: Quantification of the accuracy and precision of the intraoral digital scanner (3M True Definition Scanner - IOS) was performed using a metrology gauge block and a profilometric calibration model. Thirty-four human extracted molars with endodontic access cavities were scanned using both intraoral scanning (test scanner) in high-resolution mode, and µCT (reference scanner: GE Locus SP µCT scanner) in high- (HiResCT) and low- (LoResCT) resolution modes. Comparisons of volumetric accuracy and 3D profilometric deviations were performed using surface metrology software. One-way repeated measures analysis of variance (ANOVA), in combination with the Bonferroni post hoc test, was implemented to compare the differences in volume measurements between scanning methods. RESULTS: Digital scanning revealed smaller volume measurements by 1.36% and 0.68% compared to HiResCT and LoResCT, respectively. There was a statistically significant difference in the volumetric measurements obtained from the IOS scanner and both HiResCT and LoResCT scans (P < 0.001). Analysis of the mean 3D profilometric deviations revealed that the IOS displayed greater surface deviation (± 27/33 µm) vs HiResCT and LoResCT (± 16/32 µm). CONCLUSIONS: Although volumetric measurements of endodontically accessed teeth were up to 1.36% smaller in comparison to µCT, the digital scanner was able to reliably measure the extra- and intracoronal aspect of the endodontically accessed tooth.

Experimental polyethylene-hydroxyapatite carrier-based endodontic system: an in vitro study on dynamic thermomechanical properties, sealing ability, and measurements of micro-computed tomography voids.

The dynamic thermomechanical properties, sealing ability, and voids formation of an experimental obturation hydroxyapatite-reinforced polyethylene (HA/PE) composite/carrier system were investigated and compared with those of a commercial system [GuttaCore (GC)]. The HA/PE system was specifically designed using a melt-extrusion process. The viscoelastic properties of HA/PE were determined using a dynamic thermomechanical analyser. Human single-rooted teeth were endodontically instrumented and obturated using HA/PE or GC systems, and then sealing ability was assessed using a fluid filtration system. In addition, micro-computed tomography (µCT) was used to quantify apparent voids within the root-canal space. The data were statistically analysed using one-way anova and post hoc tests. The HA/PE composite exhibited important modulus and damping changes with an increase of temperature. The HA/PE system was more flexible than GC as the modulus of GC appeared to be significantly higher than that of HA/PE as a result of the high positive glass transition temperature (Tg ). However, HA/PE and GC presented similar sealing abilities. In conclusion, because sealing ability and voids formation were comparable between the tested materials, the experimental HA/PE system may be considered a suitable alternative material for root-canal obturation. Moreover, HA/PE possesses specific viscoelastic behaviour and lower melting points, which may facilitate root-canal retreatments.

Isolation of Propionibacterium acnes among the microbiota of primary endodontic infections with and without intraoral communication.

OBJECTIVES: The presence of opportunistic pathogens such as Propionibacterium acnes (P. acnes) may contribute to the endodontic pathology. The presence of P. acnes may be influenced by different endodontic conditions. The aims of the study were firstly, to identify P. acnes within the whole cultivable microbiota of primary endodontic infections, to investigate which P. acnes phylotypes predominate in such infections and secondly to determine if the presence of an "open" communication (e.g. a sinus) can be associated with the isolation of P. acnes from the root canal. MATERIAL AND METHODS: The predominant cultivable microbiota of 15 primary endodontic lesions (7 without communication with the oral environment and 8 with an open communication) were identified using partial 16S ribosomal RNA (rRNA) gene sequence analysis. The identification of the organism was determined by interrogating the Human Oral Microbiome Database. The P. acnes isolates were typed on the basis of the recA gene sequence comparison. A neighbor-joining tree was constructed using MEGA 4.1 with the inclusion of known recA sequences. RESULTS: There was no difference in the number of species identified from lesions without communication (5.86 ± 3.7) and those with communication (5.37 ± 3.6) (P > 0.05). PCR-based 16S rRNA gene sequencing revealed P. acnes as the most prevalent isolate recovered from lesions with communication. recA gene sequencing revealed two phylogenetic lineages present in lesion with communication, with mainly type I (further split into type IA and type IB) and type II. CONCLUSIONS: The presence of P. acnes as opportunistic pathogens has been confirmed and may sustain the traits observed in specific clinical presentations. CLINICAL RELEVANCE: Clinical management of open lesions may require further disinfection to eliminate opportunistic bacteria.

Effect of adhesive materials on shear bond strength of a mineral trioxide aggregate.

PURPOSE: To compare the shear bond strength (SBS) and fractography between mineral trioxide aggregate (MTA) and glass-ionomer cement (GIC) or resin composite (RC) after varying MTA setting time intervals. METHODS: MTA was mixed and packed into standardized cavities (4 mm diameter x 3 mm depth) in acrylic blocks. RC with 37% H3PO4 and type 2 (etch and rinse) adhesive, or conventional GIC was bonded to the exposed MTA sample surfaces after 10-minute, 24-hour, 72-hour and 30-day MTA setting intervals (n = 10/group, eight groups). Samples were stored (37°C, 24 hours, 100% humidity) before SBS testing and statistical analysis (ANOVA, Tukey LSD, P < 0.05). Fractography was undertaken using stereomicroscopy for all samples and three random samples/group by using SEM. RESULTS: Significant differences between all groups were found (P= 0.002). SBS of RC:MTA (Max 5.09 ± 1.79 MPa) was higher than the SBS of GIC:MTA (Max 3.74 ± 0.70 MPa) in 24-hour, 72-hour and 30-day groups except in the 10-minute MTA setting time groups, where SBS of GIC:MTA was higher. There was a significant effect of time on SBS of RC: MTA (P = 0.008) and no effect on SBS of GIC:MTA (P = 3.00). Fractography revealed mixed (adhesive/cohesive) failures in all groups; in RC:MTA groups there was a decrease in adhesive failure with time in contrast to the GIC:MTA groups.

What do dental students know about trauma?

AIM: To assess the baseline knowledge, knowledge acquisition and retention of dental undergraduate students in dental trauma, and the impact of a lecture on their level of confidence in managing traumatic dental injuries. MATERIAL AND METHODS: A total of 145 dental undergraduate students from King's College London were invited to attend a lecture on dental trauma. The participants were asked to complete a questionnaire on dental trauma before (T0), immediately after (T1) and 6 months (T2) following a 1-h lecture. RESULTS: Seventy of the 145 students participated in the study. The level of knowledge at T0, T1 and T2 was 64.9%, 83.2% and 69.5%, respectively. The increase in score was statistically significant between T0 and T1, and between T0 and T2. A significant decrease in score was also found between T1 and T2. Sex, level of education and whether or not the participants received previous teaching in dental trauma were not significant in predicting a change in score. The level of confidence increased significantly from 2.14 at T0 to 3.13 at T2. Participants who received teaching in dental trauma previous to the lecture were significantly more confident at T0. CONCLUSIONS: Lectures are effective at improving the knowledge and retention of knowledge of dental undergraduate students in dental trauma. However, retention of the knowledge is time limited suggesting that education should be repeated after a certain period of time to ensure that a high level of knowledge is maintained.

Penetration depth of monomer systems into acrylic resin denture teeth used as pontics.

STATEMENT OF PROBLEM: The ways of softening and dissolving the surface of acrylic resin denture teeth need to be specified to obtain more durable prosthetic treatments that include resin denture teeth. PURPOSE: The purpose of this study was to analyze the penetration depth of 4 monomer systems applied during different exposure times on the acrylic resin denture teeth used as pontics of directly fabricated fiber-reinforced composite fixed dental prostheses. The penetration depth contributes to the adhesion of the tooth to the adhesive resin. MATERIAL AND METHODS: Ninety-six specimens were divided into 3 groups according to the acrylic resin denture tooth used: Artic 8 (Heraeus Kultzer), experimental tooth (GC), and Vitapan (Vita). Each group was divided into 4 subgroups according to the monomer system used: methylmethacrylate (99%), composite primer, a flowable composite resin, and a photopolymerizing dimethacrylate resin. The 4 monomer systems were labeled with rhodamine B to determine their penetration depth into the acrylic resin denture teeth. After exposure times of 1, 5, 15, and 60 minutes, the monomers were photopolymerized for 5 minutes, with the exception of methylmethacrylate. The specimens were cut orthogonally from gingival to occlusal in 4 slices (n=8/subgroup). The penetration depths of monomers were measured by a confocal scanning type microscope. Differences in the penetration depths were evaluated with ANOVA. RESULTS: ANOVA (R(2)=.699) revealed significant differences in the penetration depths according to the exposure times (P<.001), monomers (P<.001), brands used (P=.047), and their mutual interaction (P<.001). CONCLUSIONS: The ability of monomers to penetrate the surface of acrylic resin denture teeth was influenced by the monomer systems, which might improve the bond between the pontics and the fiber-reinforced composite frameworks of fixed dental prostheses.

The Dental Practicality Index - to treat or not to treat.

The Dental Practicality Index (DPI) has been designed to describe, on a clinical level, the 'practicality' of restoring a tooth versus referring to secondary care or extraction.The systematic approach of DPI has been shown to improve decision-making and confidence in treatment planning when used by young dentists. In addition, there is good evidence demonstrating that it provides an accurate estimation of the outcome of treatment. The DPI enhances clinician-patient communication and ultimately the consent process.

Prevalence of Apical Periodontitis in Patients with Autoimmune Liver Diseases on Immune Suppressants and Immune Modulators: A Cross-sectional Study.

INTRODUCTION: Autoimmune liver diseases (ALDs) are chronic conditions generated by an immune-mediated autoaggressive inflammatory reaction in genetically susceptible individuals. The purpose of this study was to evaluate the prevalence of apical periodontitis (AP) in patients suffering from ALDs undergoing treatment with the immune suppressants glucocorticoids, azathioprine, and/or ursodeoxycholic acid. METHODS: The ALD group included 46 patients (11 men and 35 women, average age = 57.9 ± 11.8 years) and 1186 teeth. The control group included 50 healthy patients not taking any medications (15 men and 35 women, average age = 58.6 ± 10.4 years) and 1251 teeth. Demographic data and medical, pharmacologic, and dental history were recorded. Dental and radiographic examinations were performed. The presence of AP; the periapical index score; decayed, missing, and filled teeth; quality of restoration, and root canal treatment were evaluated. The influence of the medications the patients were taking on the prevalence of AP was also tested. RESULTS: The prevalence of AP was significantly lower in ALDs than in the control group at the patient (P = .019) and tooth level (P = .014). Smoking and age were associated with a significant increase in AP in cases and controls (P = .045 and P = .001, respectively). In both groups, endodontically treated teeth showed a higher prevalence of AP. CONCLUSIONS: Considering the limitations because of the observational nature of the study, the patients affected by ALDs liver diseases and undergoing treatment with immune suppressors (often associated with immune modulators) were found to exhibit a lower prevalence of AP.

Prognostic Factors Affecting the Outcome of Surgical Root Canal Treatment-A Retrospective Cone-Beam Computed Tomography Cohort Study.

Aim: To assess the association between demographic and clinical variables and the outcome of root-end surgery using digital periapical radiographs (PA) and cone-beam computed tomography (CBCT). Methodology: One hundred and fifty teeth that received endodontic microsurgery were clinically and radiographically examined (PA and CBCT scans) after 1 and 2 years. Two calibrated endodontists evaluated the radiographic healing based on a six-point outcome classification. The outcome was classified using both strict (healed) and loose (healing) criteria. The success rates were calculated, and several outcome prognostic factors were assessed. Results: One hundred and fifty teeth were assessed with both radiographic systems. When "loose" success criteria were applied using PA, 90% (n = 135) of teeth were assessed as having had a favourable outcome (90%; 95% CI: 85.2-94.8%), whereas 90.7% (n = 136) of teeth showed a successful outcome when assessed with CBCT (90.7%; 95% CI: 86.0-95.3%). When "strict" success criteria were applied, there was a statistically significant difference (p = 0.018) between the success rates of mineral trioxide aggregate (MTA) (63.7%) and Biodentine (95.5%). Conclusions: Within the limitations of this study, endodontic microsurgery showed a high success rate. Among all the demographic and clinical variables assessed, in the multiregression analysis, only the use of Biodentine was associated with a higher proportion of "complete" healings compared to MTA or Intermediate Restorative Material (IRM) when assessed using CBCT. MTA and Biodentine performed similarly when "incomplete" healings were regarded as successful outcomes.

Shaping ability of Procodile and R6 Reziflow nickel-titanium reciprocating instruments in curved mesial root canals of mandibular molars: A MicroCT study.

To compare the shaping ability of Procodile and R6 Reziflow instruments used in reciprocating motion in severely curved root canals, assessed with micro-computed tomography (µCT). Fourteen extracted human mandibular first molars were randomly assigned to two instrumentation techniques (n = 14 mesial root canals): Procodile or R6 Reziflow. For both groups, root canals were prepared to the working length up to a size 25, .06 taper. Molars were virtually divided into apical, middle and coronal thirds and µCT was used to scan all samples pre- and post-root canal. Canal transportation, centring ability, volume, surface area and unprepared area were evaluated. Geometrical parameter changes were compared with preoperative values (one-way analyses of variance and Tukey multiple comparison post-hoc test) between groups and Student t-test within groups (α = 0.05) Significantly less transportation was observed associated with the Procodile technique in the molar's coronal third compared to the R6 Reziflow technique (p < .05). No significant differences in root canal centring ability, volume, surface area and unprepared area were observed. Procodile showed a lower percentage increase of surface area compared to R6 Reziflow (p < .05). The Procodile and R6 Reziflow techniques applied to first molar root canal performed similarly except for the less transportation observed in the coronal third using Procodile. RESEARCH HIGHLIGHTS: MicroCT analysis of canal geometry before and after instrumentation revealed that Procodile and R6 Reziflow showed a similar shaping ability to shape curved root canals without substantially modifications of the original tooth anatomy.