In Vitro Evaluation of the Accuracy of Three Electronic Apex Locators Using Different Sodium Hypochlorite Concentrations.

Background and Objectives: The aim of this study was to compare the accuracy of three types of electronic apex locators (EALs) when two different concentrations of NaOCl irrigation solutions are used by two operators. Materials and Methods: After creating the access cavities for 20 single rooted extracted teeth, the actual canal length (ACL) of each canal was determined visually using a #10 file and magnification. The teeth were subsequently inserted in plastic molds filled with alginate. The electronic measurement of root canal length (EWL) was performed using three different electronic apex locators: Root ZX II, Apex ID, and Dual Pex. Two independent operators, an endodontic specialist with 20 years practice and an undergraduate student in the final year of study, performed the irrigation procedures with two different concentrations of NaOCl (2% and 5.25%), and then measured the EWL using each of the EALs. The accuracy of all EALs, was determined in each case by subtracting the EWL from the ACL. Statistical analyses were performed using one-way ANOVA test. Results: In the presence of 2% NaOCl solution, for a margin error of ±0.5 mm, Root ZX II, Apex ID, and Dual Pex presented an accuracy of 90%, 80%, and 85% respectively. The increase in the concentration of the irrigation solution affected the accuracy of Root ZX II and Apex ID for both operators, diminishing it to 75% for the same margin error, but improved Dual Pex's accuracy to 100%. Conclusions: The best accuracy in working length determination was obtained by Root ZX II for 2% NaOCl solution and by Dual Pex for 5.25% NaOCl solution with no significant statistical difference when compared.

Properties of Nanohybrid Dental Composites-A Comparative In Vitro Study.

(1) Background: the current study investigated three nanohybrid composites: two commercial products ClearfilMajestyTM (CM) and HarmonizeTM (HU), compared with an experimental product PS2. (2) Methods: Two sample types were molded using Teflon dies. The first sample type was represented by standard discs (20 mm diameter and 2 mm thickness) (n = 60, 20/each material), used for surface conditioning investigation, specifically roughness monitoring and color stability analysis using AFM and the CIELab test, respectively. The second sample type was a standard cylindrical specimen (4 mm diameter and 6 mm height) for compression testing (n = 60, 20/each material). After complete polymerization, the samples were ground with sandpaper and further polished. The filler size and distribution in the polymer matrix were investigated with SEM. Data were statistically analyzed using the Anova Test followed by Tukey's post hoc test on the Origin Lab 2019 software produced by OriginLab Corporation, Northampton, MA, USA. (3) Results: A mono-disperse system was identified in HU samples, while CM and PS2 revealed both nano- and microfiller particles. The samples' observation after immersion in coffee and tea indicated that a lower roughness combined with optimal filler lamination within the polymer matrix assured the best color preservation. The compression strength was lower for the HU sample, while higher values were obtained for the complex filler systems within CM and PS2. (4) Conclusions: the behavior of the investigated nanohybrid composites strongly depends on the microstructural features.

Smile Design and Treatment Planning-Conventional versus Digital-A Pilot Study.

INTRODUCTION: Several methods are currently available for providing a preview of the prosthodontic treatment, including computer simulations, 3D models, wax-ups, and mock-ups. The aim of this study is to compare the aesthetic aspects and assessment of conventional versus digital prefigurative methods. METHODS: The study included 5 patients and 3 observers, for each of whom a wax-up was made in both the conventional and digital techniques. The analog method, which implied a mock-up molding with a silicone matrix of the wax-up, was compared to a digital workflow, which consisted of a mock-up milling from a digital design. The patient's clinical mock-ups were recorded with digital photographs and assessed for nine different criteria by three observers. RESULTS: The analysis has shown a balanced assessment of the aesthetic criteria without any significant difference between the analog and digital prefigurative methods. CONCLUSIONS: Between the two wax-ups (conventional and digital), there were some variations in smile and dental criteria; however, the obtained data were very similar. When it comes to the smile criteria, the general average grades of the mock-ups conducted using the conventional method are slightly higher than the ones using the digital technique.

Polymer Mixtures for Experimental Self-Limited Dental Burs Development-A Preliminary Approach (Part 1).

Alternative techniques have been investigated for effectiveness in caries removal because conventional metallic dental burs can lead to an excessive loss of sound tissue. The aim of the present study is to realize a preliminary approach in obtaining effective polymer mixtures for polymeric bur development, capable of removing primary dental caries using combinations of polymers to ensure the requirements for such instruments, but also a greater compatibility with the teeth structure. This study assessed the main mechanical properties, water sorption, solubility and microscopic structure of four new polymer mixture recipes to provide essential features in obtaining experimental self-limited dental burs. Two mixtures have in their composition polymer mixtures of Bis-phenol A diglycidyl ether dimethacrylate/Triethylene glycol dimethacrylate/Urethane dimethacrylates (R1, R2), and two other mixtures have Bis-phenol A diglycidyl ether dimethacrylate/Polymethyl methacrylate/Methyl methacrylates (R3, R4). The incorporation of nanoparticles into the polymer matrix has become essential due to the need of polymer biocompatibility increasing along with teeth surface remineralization, so that the powder charge was added to four recipes, such as 5% glass with BaF2 and 0.5% graphene with silver particles. All data sets were analyzed using the One-Way ANOVA test. R3, R4 showed higher compressive strength and diametrical compression values; these values increased when glass and graphene were added. Moreover, the addition of glass particles lead to an increase in flexural strength. Regarding the sorption, sample R3 had the most significant differences between day 69 and the rest of the investigation days, while the solubility varied at different intervals. From the mechanical evaluation, we could conclude that the Bis-GMA/PMMA/MMA mixtures fit the mechanical characteristics supported by polymer burs, following future studies regarding their use on the affected dentin.

Oral Health-Related Knowledge, Attitude and Practice among Patients in Rural Areas around Cluj-Napoca, Romania.

The intent of the KAP (knowledge, attitude, practices) survey is to collect information about a specific target group related to their knowledge, what they consider to be known, and what they do about a particular topic. The aim of this study was to identify the level of importance of oral health, especially the level of knowledge, attitude and practices of rural patients around Cluj-Napoca, Romania. MATERIAL AND METHODS: A questionnaire consisting of five parts was used, trying to assess the self-perception of oral health, knowledge and attitude towards oral health, dental hygiene practices and eating habits. A clinical examination was also performed in order to identify the number of missing teeth, the caries and the presence of calculus. RESULTS: The study revealed that most patients have an average and good self-perception of oral health, although three-quarters of them have calculus deposits, and about half of them have more than three carious lesions and at least one extracted tooth. There is also a discrepancy between declared knowledge of oral health, eating habits and dental practices. CONCLUSIONS: The basic knowledge of rural patients about oral health can be considered satisfactory, but the practices, unfortunately, do not reflect this knowledge.

Development of New Experimental Dental Enamel Resin Infiltrants-Synthesis and Characterization.

The aim of the present study was to obtain experimental infiltration materials, intended for the treatment of dental white spots, and to investigate them. Two series of infiltrants (P1-P6)/(P1F-P6F) were obtained, based on different monomer mixtures, without/with glass filler (with fluoride release ability). Each infiltrant from the second series contained the same amount of glass powder, and each infiltrant from the (P-PF) group contained the same resin composition. The characteristics of the experimental infiltrants were investigated by degree of conversion (DC), mechanical strength, water sorption (WS), and fluoride release, in addition to residual monomer for (P1F-P6F) infiltrants. The results were compared with those obtained for commercial Icon infiltrant. For the experimental infiltrants, without/with filler, the recorded DC was in the range of 58.27-89.70%/60.62-89.99%, compared with Icon (46.94%) 24 h after polymerization. The release of fluoride depends on the permeability of the polymer matrix, with respect to the water sorption, which may help to diffuse ions in the storage medium but which can also influence the release of residual monomers. The highest flexural strengths were recorded for the (TEGDMA/HEMA/Bis-GMA) infiltrants (133.94 ± 16.389 MPa/146.31 ± 7.032 MPa). The best experimental infiltrants were P2 and P2F (Bis-GMA/HEMA/TEGDMA).

The Influence of Hepatitis C Virus Infection on ORAL Health-Related Quality of Life in Patients with Oral Lichen Planus.

BACKGROUND: oral lichen planus (OLP) is a mucocutaneous disease that affects about 4% of the global population. Hepatitis C virus (HCV) was linked to lichen planus. The current study aimed to assess the impact of OLP associated or not with HCV infection on the oral health-related quality of life (OHRQoL). METHODS: The study included patients diagnosed with OLP who filled in the Romanian version of OHIP-14 questionnaire at their first appointment and 6 months later, after the OLP treatment. A control group of OLP-free subjects similar as age and sex was also included in the study. Results: 68 patients with OLP and 46 controls were included in the study. The OHIP scores are significantly higher on OLP group than controls (p-value < 0.0001) and significantly reduced at 6-month follow-up (p-values: < 0.0001 pre- vs. post-treatment in OLP group). Patients with and without HCV associated with OLP demonstrated a similar oral quality of life (p-values > 0.05). Conclusions: the OHRQoL for patients suffering from OLP is compromised but is improved after treatment. The HCV associated with OLP did not influence the overall OHRQoL, but the patients who associate HCV reported more frequently aching in the mouth and discomfort eating food at six-month follow-up.

Surface Characteristics, Fluoride Release and Bond Strength Evaluation of Four Orthodontic Adhesives.

Orthodontic adhesives have similar properties in terms of fluoride release, roughness, shear bond strength or cement debris for specific clinical conditions. Three commercial consecrated orthodontic adhesives (Opal Seal®, Blugloo®, Light Bond®) were compared with an experimental orthodontic material (C1). Brackets were bonded to enamel using a self-etch technique followed by adhesive application and then de-bonded 60 days later. Share bond strength evaluation, scanning electron microscopy, atomic force microscopy and fluoride release analysis were performed. The highest amount of daily and cumulative fluoride release was obtained for the experimental material, while the lowest value was observed for Opal Seal®. The materials evaluated in the current study presented adequate shear bond strength, with the experimental material having a mean value higher than Opal Seal and Blugloo. The atomic force microscopy measurements indicated that the smoothest initial sample is Opal Seal® followed by Light Bond®. Scanning electron microscopy evaluation indicated different aspects of cement debris on the enamel and/or bracket surface, according to the type of adhesive. The experimental material C1 presented adequate properties in terms of shear bond strength, fluoride release, roughness and enamel characteristics after de-bonding, compared to the commercial materials. Under these circumstances, it can be considered for clinical testing.

Preparation and In Vitro Characterization of Gels Based on Bromelain, Whey and Quince Extract.

The growing interest in the appearance and color of teeth has led to the emergence of a wide range of teeth whitening methods, both in dental offices and in patients' homes. Concerns about the possible side effects or toxic effects of peroxide-based whitening gels leads to the identification of alternative whitening methods, based on natural compounds with mild action on tooth enamel and remineralizing effect. In this context, this study describes the preparation and in vitro analysis of whitening gels based on natural active agents-bromelain, quince and whey-using organic (polyacrylate, polyethylene glycol) and/or inorganic (silicate) excipients. Five natural products gels were prepared, containing bromelain extract, quince extract and whey, in various proportions. Two supplementary gels, one containing Lubrizol and another containing SiO2, were prepared. All gels were submitted for multiple in vitro analysis such as: SDS-PAGE analysis, UV-vis and FTIR spectroscopy, SEM microscopy, antibacterial activity on Streptococcus mutans ATCC 25175, Porphyromonas gingivalis ATCC 33277, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. The quince extract sample was the only one which completely discolored the blue dye on SDS-PAGE analysis. On the UV-vis spectra, the 303 nm band is assigned to an in situ modified form of bromelain. SEM images of gels containing SiO2 particles show evident marks of these particles, while the rest of the gels containing Lubrizol or whey are more uniform. Regarding antibacterial tests, the SiO2 gel samples did not show inhibition in any strains, but the other tested samples varied in the size of the inhibition diameter depending on the amicrobial strain tested; the protease activity of bromelain modulates the composition of the added whey proteins. Bromelain added as a nanoencapsulated assembly better preserves its integrity. The prepared gels showed antibacterial properties.

Effects of Monomer Composition of Urethane Methacrylate Based Resins on the C=C Degree of Conversion, Residual Monomer Content and Mechanical Properties.

(1) Background: This study investigated the influence of Bis-GMA, TEGDMA, UDMA, and two different polyethylene glycol (PEG)-containing, UDMO-based co-monomers on the Young's modulus and flexural strength, degree of methacrylate C=C double bond conversion and residual monomer elution of experimental dental resins. (2) Methods: Urethane methacrylate-based monomer was synthesised via a radical chain growth polymerization mechanism using PEG in order to improve the mechanical properties. Dental resins were formulated using Bis-GMA, UDMA, or UDMO as base monomers combined with TEGDMA as a dilution monomer and DMAEM + CQ as the photo-initiator system. Degree of conversion (DC), mechanical properties, and residual monomer content of light-activated methacrylate resin formulations were evaluated and statistically analysed by ANOVA and a Tukey's test. (3) Results: PEG-containing UDMO resins had lower Young's modulus and elastic strength than UDMA-derived resin for all irradiation times. The highest DC (67,418%) was observed for the PEG-containing UDMO-based resin formulation when light cured for 40 s. For all samples, DC increased with the photo-polymerization time. The amount of residual monomer decreased after increasing the light-curing period from 20 to 40 s, resin with UDMO content 0.01 mol of PEG having the smallest amount of free eluted monomer. (4) Conclusions: A strong structure-property relationship exists in photo-cured dimethacrylate-based dental resins. The time and quantity of the photochemical initiation system can influence the physical-mechanical properties of the resins but also the monomers in their composition.

Treatment trends in oral lichen planus and oral lichenoid lesions (Review).

Oral lichen planus (OLP) is a chronic inflammatory disease, associated with altered cell-mediated immunological function. It has long-term evolution, repeated exacerbations, sometimes painful and resistant to treatment, even all of these, OLP significantly affects patient's life quality. Not least, OLP is accompanied by an increased risk of malignant transformation. A wide spectrum of therapeutic options is available, but none are curative. In this review, 58 structured studies on the clinical symptomatology and treatment strategy of OLP were analyzed. The literature research was performed according to the criteria of the PRISMA system. This study summarizes current knowledge regarding management of OLP and oral lichenoid lesions, discusses the challenges of choosing an adequate treatment and, in attempt to improve the quality of patient life, trying to describe a therapeutic algorithm that takes into consideration the clinical features of the disease. Current OLP therapy aims at eliminating all mucosal-related lesions, reduce symptomatology and decrease the risk of oral cancer and include corticosteroids, immunomodulatory agents, retinoids, ultraviolet irradiation and/or laser therapy.

Dentists' perspectives on the reconstruction possibilities of a non-vital tooth.

BACKGROUND AND AIMS: The decision-making process when restoring a non-vital tooth is influenced by multiple factors. This study aimed to survey the dentists' preferences regarding cast post-and-core and fiber post techniques for the reconstruction of non-vital teeth and to identify a correlation between reconstruction technique and practitioners characteristics, or dental characteristics. METHODS: The survey instrument was a questionnaire, which included a general part with questions regarding the practitioner's profile (gender, age, years of experience, pattern and location of practice, etc.) and the dental characteristics (anterior or posterior position of the tooth on the arch, the amount of dental remaining tissues, etc.) and a technical part, containing more specific questions regarding the manufacture and performance of root-coronal reconstructions. RESULTS: Among the surveyed practitioners (n=35), 69.7% use more often cast post-and-core reconstructions (CPR) while 30.3% choose fiber post reconstructions (FPR). No difference in the reconstruction type was observed regarding patient's age (p=0.23) or gender (p=0.092). The para-function criterion was considered important by 8.23% of the participants. When deciding the type of the root-coronal reconstruction depending on the remaining dentine walls, CPRs are significantly more frequently used in posterior areas (p=0.043) or when para-functional habits exist (p=0.022). CONCLUSION: Cast post-and-core represent the most frequently used type of reconstruction for non-vital teeth. Fiber post reconstructions are indicated in the aesthetic zone and when the amount of healthy remaining dental structure is higher.

Comparative apical sealing evaluation of two bioceramic endodontic sealers.

AIM: The current study aims to evaluate, using scanning electronic microscopy, the sealing ability of two bioceramic endodontic sealers, one consecrated and one experimental. METHODS: Twenty monoradicular teeth were included in the study. The teeth were endodontically prepared at the working length. The shaping and cleaning involved the use of chelating gel MM EDTA 19% and continuous irrigation with sodium hypochlorite 2.5%. The radicular filling was performed using gutta-percha in association with a sealer. Ten teeth were filled with consecrated endodontic filling material and the others ten with the experimental bioceramic based sealer. RESULTS: The evaluation of the sealers using SEM analysis allowed the identification and the measurement of gaps on the radicular dentin/sealer interface and the degree of apical sealing ability. No significant statistical difference was observed between the gap dimensions in the three areas for the tested bioceramic materials (p<0.005). In the apical region a homogenous layer with extensions intersecting the hybrid layer was observed when the experimental bioceramic sealer was used. In case of teeth filled with commercial sealer, peripheral hybrid extended areas were identified. CONCLUSIONS: The two bioceramic sealers presented similar apical sealing. Gaps were identified in both sealers but also the presence of hybrid layer was identified.

Comparative radiographic assessment of a new bioceramic-based root canal sealer.

BACKGROUND AND AIMS: The aim of this study was to assess the radiopacity of two bioceramic-based root canal sealers, the conventional TotalFill BC sealer (FKG Dentaire Switzerland) and a new experimental filling material developed in collaboration with 'Raluca Ripan' Institute for Research in Chemistry, Cluj-Napoca. METHODS: Five disc samples were prepared using both materials (10 mm diameter × 1 mm thickness), being subjected to digital radiography together with aluminum step wedges (1 to 12 mm in thickness), in accordance with ISO 6876: 2012. Radiopacity was determined by the computer analysis of the images obtained. Four different areas were selected for each sample, corresponding to a disk-sample quadrant. Statistical analysis was performed using ANOVA. RESULTS: Both materials showed a radiopacity that was 3 mm greater than the equivalent thickness of aluminum. Total Fill BC showed greater radiopacity than the experimental material, but the differences were not statistically significant. CONCLUSIONS: Both materials comply with ISO 6876: 2012 recommendations on minimum radiopacity.

Etiological factors associated with temporomandibular joint disorder - study on animal model.

The etiology of temporomandibular disorder (TMD) is multidimensional: biomechanical, neuromuscular, bio-psychosocial and biological factors may contribute to the disorder. The main objectives of our study were investigation and analysis of the degree of involvement for several presumptive etiological factors of TMD: biomechanical stress (BS), estrogen hormones (EH) and emotional stress (ES). Six groups (n=10) of mature female Wistar rats were included in the study. Single presumptive etiological factor was applied in three groups (BS, EH and ES groups) and also association of presumptive etiological factors were applied in two groups (BSEH and BSES groups). No etiological factor was applied for the control group. Animals were sacrificed after a 60 days period and histological analysis of the temporomandibular joint (TMJ) tissues was performed. The changes in the mandibular cartilage, articular disc, temporal bone and synovial tissue were observed under optical magnification and quantified. All samples developed changes in the thickness of the condylar cartilage comparing to control group. The reduction was highly statistical significant for the EH, ES and BSES groups (p<0.001) and statistical significant for the BS and BSEH groups (p<0.05). The most important modifications with severe cartilage thickness reduction have been obtained in case of BSES group. In conclusion, biomechanical, emotional stress and estrogens can be considered as possible etiological factors in TMD.

In vitro evaluation of root canal preparation with two rotary instrument systems - Pro Taper and Hero Shaper.

BACKGROUND AND AIMS: The purpose of this study was to compare several parameters of root canal preparation using two different rotary Nickel-Titanium instruments: Pro-Taper (Dentsply Maillefer, Ballagigues, Switzerland) and Hero-Shaper (Micro Mega, Besancon, France). METHODS: Twelve extracted maxillary premolars were randomly divided into two groups and embedded into a muffle system. All root canals were prepared to size 25 using Pro-Taper or Hero-Shaper rotary instruments. The following parameters were evaluated: root canal form, centering capacity of the instrument, the presence of residual dentinal debris and smear layer on the root canal walls, working time and the occurrence of intraoperative accidents. Statistical analysis was performed using the chi(2) test (p=0.05). RESULTS: The majority of the root canals prepared with Hero Shaper (88.89%) and ProTaper (77.78%) showed a round or oval cross-section postoperatively. Superposition of pre- and postoperative photographs of the cross-sections showed that for the coronal third of the root canals the Hero Shaper performed in a superior manner, while for the apical third better results were obtained with the Pro Taper system. Cleanliness of the root canal walls was investigated under the SEM, in the middle third of the canal, using a five-score system for debris and smear layer. For debris Hero Shaper and Pro Taper rotary systems achieved 66.67% and 50% scores of 1 or 2, respectively. The results for the smear layer were similar: cleaner root canal walls were found after preparation with Hero Shaper (66.67% scores 1, 2), followed by Pro Taper (50%). Mean working time was shorter for Hero Shaper (124s) than for Pro Taper (184s); the difference was not significant. CONCLUSIONS: Within the limits of this study, both systems had almost the same cleaning ability and excellent centering capacity.

Factors involved in the etiology of temporomandibular disorders - a literature review.

BACKGROUND AND AIM: This review aims at presenting a current view on the most frequent factors involved in the mechanisms causing temporomandibular disorders (TMD). METHOD: We conducted a critical review of the literature for the period January 2000 to December 2014 to identify factors related to TMD development and persistence. RESULTS: The etiology of TMD is multidimensional: biomechanical, neuromuscular, bio-psychosocial and biological factors may contribute to the disorder. Occlusal overloading and parafunctions (bruxism) are frequently involved as biomechanical factors; increased levels of estrogen hormones are considered biological factors affecting the temporo-mandibular-joint. Among bio-psychosocial factors, stress, anxiety or depression, were frequently encountered. CONCLUSIONS: The etiopathogenesis of this condition is poorly understood, therefore TMDs are difficult to diagnose and manage. Early and correct identification of the possible etiologic factors will enable the appropriate treatment scheme application in order to reduce or eliminate TMDs debilitating signs and symptoms.