Development of nanobiosilicate, tricalcium phosphate and chlorhexidine materials for biomineralization with crystallographic similarity to hydroxyapatite and biomodified collagen.

OBJECTIVES: The aim of this work is to test experimental cements, doped with a silicate based bioactive nanoparticle (NanoBiosilicate). Methods, we synthesized a glass nanoparticle by Sol-Gel Stöber method, used to be incorporated in a dental material for endodontic uses. MATERIALS AND METHODS: We assess the mineralizing properties and biocompatibility. Besides the crystallography characterization of the resultant new crystals. Results, After analysis, and comparison with commercial materials, the material tested was similar in mechanical properties required by ISO, The ion release was effective after 2 hr. of setting and the novel material was cell compatible accepted by ISO. RESULTS: We found new formed Calcium Phosphate peaks in the spectroscopic analysis (FTIR), remarkably the crystals formed were comparable to hydroxyapatite when analyzed with a Selected Area Electron Diffractometer, with rings of 2.84 Å for 002, and the 2.77 Å is also visible for 210. The 6.83 Å and 6.88 Å, for respective 222 and 004. The incorporation of Chlorhexidine was not detrimental for this property, Significance, the features mentioned represented a progress in biomineralization field that was associated to an improved mineral structure formation with increased crystallographic similarity to natural hydroxyapatite. When chlorhexidine was added a favorable biomodification of the remaining collagen in dentinal walls and antimicrobial activity potential were also observed.

Do non-clinical subjective factors influence the treatment decisionmaking of Brazilian dentists?

The literature contains little information on several non-clinical factors such as the association between graduate residency programs and the application of minimally invasive dentistry, or on dentists' clinical decision-making processes for replacing restorations for esthetic reasons. This study evaluated whether non-clinical subjective factors influence the treatment decisions made by Brazilian dentists regarding technical and esthetic matters. Dentists were invited to participate in a cross-sectional survey by answering an electronic questionnaire containing clinical cases, regarding what treatment they would select for: T1 - a molar tooth with significant crown destruction and spontaneous pain, and T2 - premolar teeth with extensive amalgam restorations and no carious lesion or associated complaint. The survey also included questions about subjective variants (sociodemographic and professional). Chi Square test and Fischer's Exact test were used toanalyzetheanswers to T1, and one-factor analysis of variance and post-hoc Tamhane were applied to T2. The significance level was set at 5% for all analyses. A total 302 professionals participated in the study. For T1, it was found that clinical decision-making was influenced by the Brazilian region of clinical practice (p=0.005). For T2, a significant association was found between increased loss of patient tooth tissues and whether the professional had completed a residency program in Operative Dentistry (p=0.035), worked in a private practice (p=0.033), or if most of his/her patients belonged to a high estimated socioeconomic level (household income above $4350) (p=0.002). In conclusion, the clinical decision-making of Brazilian dentists varies according to professional profile, mainly with relation to the replacement of restorations due to esthetic concerns.

Vários fatores não clínicos, como a associação entre programas de especialização e a aplicação da odontologia minimamente invasiva, ainda são escassos na literatura. Outro aspecto relevante é a tomada de decisão clínica do dentista quanto à substituição de restaurações em função da aparência estética. Este estudo avaliou se fatores subjetivos não clínicos influenciam na tomada de decisão clínica de dentistas brasileiros com base em questões técnicas e estéticas. Foi realizado um estudo transversal com um questionário eletrônico contendo casos clínicos que foram apresentados a uma lista de profissionais. No questionário, interrogou-se o tratamento proposto para um dente molar com destruição coronária significativa e dor espontânea (T1). Também foi questionado o tratamento proposto para dentes prémolares com extensas restaurações de amálgama e sem lesão cariosa ou queixas associadas (T2). Em seguida, foram questionadas as variantessubjetivas(sociodemográfica eprofissional). Na análise de T1, foram utilizados os testes Qui Quadrado e Exato de Fischer. Em T2, foi aplicada a análise de variância de um fator e post-hoc Tamhane. Para todas as análises, o nível de significância foi estabelecido em 5%. Um total de 302 profissionais participaram deste estudo. A tomada de decisão clínica para T1 foi influenciada pela região brasileira de prática clínica (p = 0,005). Em T2, realizar especialização em Dentística Operatória (p = 0,035), trabalhar em consultório particular (p = 0,033) e a maioria dos pacientes apresentar nível socioeconômico estimado elevado (renda familiar acima de R$10.000,00) (p = 0,002) aumentou significativamente a perda de tecidos dentários. Em conclusão, a tomada de decisão clínica dos dentistas brasileiros varia de acordo com o perfil dos profissionais, principalmente no que se refere à substituição de restaurações por questões estéticas.

Do non-clinical subjective factors influence the treatment decisionmaking of Brazilian dentists? / Fatores subjetivos não clínicos influenciam na tomada de decisão do tratamento de cirurgiões-dentistas brasileiros?

ABSTRACT The literature contains little information on several non-clinical factors such as the association between graduate residency programs and the application of minimally invasive dentistry, or on dentists' clinical decision-making processes for replacing restorations for esthetic reasons. This study evaluated whether non-clinical subjective factors influence the treatment decisions made by Brazilian dentists regarding technical and esthetic matters. Dentists were invited to participate in a cross-sectional survey by answering an electronic questionnaire containing clinical cases, regarding what treatment they would select for: T1 - a molar tooth with significant crown destruction and spontaneous pain, and T2 - premolar teeth with extensive amalgam restorations and no carious lesion or associated complaint. The survey also included questions about subjective variants (sociodemographic and professional). Chi Square test and Fischer's Exact test were used to analyze the answers to T1, and one-factor analysis of variance and post-hoc Tamhane were applied to T2. The significance level was set at 5% for all analyses. A total 302 professionals participated in the study. For T1, it was found that clinical decision-making was influenced by the Brazilian region of clinical practice (p=0.005). For T2, a significant association was found between increased loss of patient tooth tissues and whether the professional had completed a residency program in Operative Dentistry (p=0.035), worked in a private practice (p=0.033), or if most of his/her patients belonged to a high estimated socioeconomic level (household income above $4350) (p=0.002). In conclusion, the clinical decision-making of Brazilian dentists varies according to professional profile, mainly with relation to the replacement of restorations due to esthetic concerns.

RESUMO Vários fatores não clínicos, como a associação entre programas de especialização e a aplicação da odontologia minimamente invasiva, ainda são escassos na literatura. Outro aspecto relevante é a tomada de decisão clínica do dentista quanto à substituição de restaurações em função da aparência estética. Este estudo avaliou se fatores subjetivos não clínicos influenciam na tomada de decisão clínica de dentistas brasileiros com base em questões técnicas e estéticas. Foi realizado um estudo transversal com um questionário eletrônico contendo casos clínicos que foram apresentados a uma lista de profissionais. No questionário, interrogou-se o tratamento proposto para um dente molar com destruição coronária significativa e dor espontânea (T1). Também foi questionado o tratamento proposto para dentes prémolares com extensas restaurações de amálgama e sem lesão cariosa ou queixas associadas (T2). Em seguida, foram questionadas as variantes subjetivas (sociodemográfica e profissional). Na análise de T1, foram utilizados os testes Qui Quadrado e Exato de Fischer. Em T2, foi aplicada a análise de variância de um fator e post-hoc Tamhane. Para todas as análises, o nível de significância foi estabelecido em 5%. Um total de 302 profissionais participaram deste estudo. A tomada de decisão clínica para T1 foi influenciada pela região brasileira de prática clínica (p = 0,005). Em T2, realizar especialização em Dentística Operatória (p = 0,035), trabalhar em consultório particular (p = 0,033) e a maioria dos pacientes apresentar nível socioeconômico estimado elevado (renda familiar acima de R$10.000,00) (p = 0,002) aumentou significativamente a perda de tecidos dentários. Em conclusão, a tomada de decisão clínica dos dentistas brasileiros varia de acordo com o perfil dos profissionais, principalmente no que se refere à substituição de restaurações por questões estéticas.

Age and experience with dental operating microscope: Do these factors influence on the post space preparation and adhesion of glass fiber posts?

This study evaluated the influence of operator's age and experience with dental operating microscope (DOM) on the cleaning of post space walls and on bond strength of glass fiber posts associated with self-adhesive resin cement. Sixty bovine roots were selected. Root canal preparation was performed and roots were filled using gutta-percha/AH Plus. For post space preparation, specimens were divided into four groups (n = 15), according to operator's age and the use of DOM: (1) ≥40 years; (2) ≥40 years with magnification; (3) <40 years; (4) <40 years with magnification. Next, a high-speed bur of the post system and torque-controlled round burs were used for cleaning of post space. Five roots in each group were evaluated for the degree of cleanliness under a stereo microscope using a scoring system. In the remaining 10 specimens from each group, glass fiber posts were cemented with RelyX U200. Two slices (1 ± 0.1 mm) prepared on each root third of all specimens were evaluated by push-out analysis. The scoring system was analyzed using Kruskal-Wallis and push-out data using ANOVA. Significance level was set at 5%. No significant difference was observed in cleaning scores among groups (p > .05). There was no significant difference when comparing the groups and the root thirds (p > .05). The adhesive failure between dentin, cement, and post predominated in all groups. Operator's age and experience with DOM did not influence the cleanliness of root canal walls or the bond strength of glass fiber posts associated with self-adhesive resin cement for post space preparation. RESEARCH HIGHLIGHTS: Although magnification is considered part of Endodontics, little is known about the variables associated. Operator's age and experience with microscope on cleaning of canals and on push-out of posts with self-adhesive resin cement were evaluated.

Clinical and Radiographic Outcomes of Regenerative Endodontic Procedures in Traumatized Immature Permanent Teeth: Interappointment Dressing or Single-Visit?

INTRODUCTION: More data are needed before affirming that single-visit approaches are effective and safe for regenerative endodontic procedures (REPs). This study compared clinical and radiographic outcomes of REPs between interappointment dressing or single-visit protocols. METHODS: Twenty young patients presenting traumatized immature teeth with pulp necrosis were divided into 2 groups. Teeth were submitted to 6% sodium hypochlorite and 2% chlorhexidine irrigation and to 17% EDTA use before blood clot induction. In the interappointment dressing group (n = 11), calcium hydroxide was used with 2% chlorhexidine gel for 21 days before scaffold induction. In the single-visit group (n = 9), the scaffold was induced during the only appointment. Patients were followed up for 24 months. Primary, secondary, and tertiary outcomes were assessed by 3 independent evaluators. Preoperative and follow-up radiographs were assessed for quantitative measurements of the apical diameter, root width, root length, and cervical barrier placement and compared between groups using the t test or Mann-Whitney U test. Categoric variables were assessed with the G test and the Fisher exact test and continuous variables with the Mann-Whitney U test. Statistical significance was set at 5%. RESULTS: One tooth showed persistence of infection. No difference was observed in cervical barrier placement (P > .05); between groups regarding primary, secondary, and tertiary outcomes (P > .05); and in parameters of quantitative radiographic outcomes (P > .05). CONCLUSIONS: Completing REPs with an interappointment dressing or a single-visit protocol presented similar clinical and radiographic outcomes. A single-visit protocol of REPs using 6% sodium hypochlorite, 2% chlorhexidine, and 17% EDTA permitted satisfactory outcomes in necrotic immature permanent teeth.

Comparison of Postobturation Pain Experience after Apical Extrusion of Calcium Silicate- and Resin-Based Root Canal Sealers.

INTRODUCTION: This study compared the intensity of postobturation pain after unintentional apical extrusion of calcium silicate-based root canal sealers (EndoSequence BC Sealer [Brasseler USA, Savannah, GA] and Bio-C Sealer [Angelus, Londrina, PR, Brazil]) with a resin-based sealer (AH Plus; Dentsply Sirona, York, PA). METHODS: A total of 330 patients referred for root canal treatment on molar teeth with asymptomatic irreversible pulpitis were recruited. Root canals were prepared using WaveOne Gold instruments (Dentsply Sirona) in a crown-down technique and irrigated with 2% chlorhexidine gel and saline solution. Next, patients were randomly distributed into 3 groups according to the root canal sealer used (n = 110): AH Plus, BC Sealer, and Bio-C Sealer. Root canal filling was then accomplished with a vertical compaction technique. Patients presenting with an unintentional extrusion of sealers (n = 13/group) were assessed for postobturation pain experience using a visual descriptor scale ranging from 0-10 at 6-, 12-, 24-, and 48-hour and 1-week intervals after treatment. Mixed analysis of variance repeated measures were used to assess the results (α = 0.05). RESULTS: The extrusion rate was similar for all sealers (~12%). There was no significant difference in the postobturation pain results between the root canal sealers evaluated (P > .05). However, after the time interval of 12 hours, AH Plus (P = .04073) and Bio-C Sealer (P = .04327) demonstrated a significant reduction in pain, whereas BC Sealer did not show differences in pain intensity, even in the maximum period evaluated of 1 week (P > .05). CONCLUSIONS: The occurrence of unintentional apical extrusion of calcium silicate-based root canal sealers presents similar postoperative pain results compared with resin-based sealers with low-intensity pain.

Clinical and Molecular Microbiological Evaluation of Regenerative Endodontic Procedures in Immature Permanent Teeth.

INTRODUCTION: This study evaluated the bacterial levels after regenerative endodontic procedures and their correlation with the treatment outcome using molecular microbiology methods. METHODS: Root canal samples of 15 necrotic immature teeth were analyzed by quantitative polymerase chain reaction. Bacteria were counted before treatment (S1), after irrigation with 6% sodium hypochlorite (S2), and after intracanal dressing (S3) using either triple antibiotic paste (n = 7) or calcium hydroxide with chlorhexidine (n = 8). The Wilcoxon test for related samples and the Mann-Whitney test were used for statistical analysis (P < .05). After a follow-up period of 12-48 months, clinical and radiographic findings were correlated with microbiological data using a linear regression model (P < .05). RESULTS: All S1 and S2 samples were positive for bacteria, but the number of positive S3 samples decreased to 53.3% (P = .001). Overall, there was a significant reduction of bacterial levels after each treatment step (S1-S2, P = .001; S2-S3, P = .02). In the triple antibiotic paste and chlorhexidine groups, 57.1% and 50% of S3 samples were positive with median numbers of 6.97 × 103 and 3.59 × 104 bacterial cells, respectively. No significant differences were found between the groups. Periapical healing occurred in all cases despite the presence of low levels of residual bacteria. However, the latter had a negative impact on the thickness of dentinal walls (R2 = 0.0043). CONCLUSIONS: Although the bacterial levels were drastically reduced after the regenerative endodontic procedures, the residual bacteria influenced the thickness of the dentinal walls.

Assessing pulp stones by cone-beam computed tomography.

OBJECTIVES: The aim of this study was to evaluate the occurrence of pulp stones by cone-beam computed tomography (CBCT) and to correlate their prevalence with patient's gender, location of tooth (right or left of maxillary or mandibular arch), group of teeth, and restorations. MATERIALS AND METHODS: CBCT images of 382 patients randomly selected from the database of the University Oral Radiology Department were retrospectively examined. A total of 2833 tooth images obtained using the i-CAT 3D Imaging System were evaluated. Image analysis was performed with the i-CAT software, and all teeth were evaluated in sagittal, axial, and coronal views. All the measurements were subjected to chi square test, odds ratio, and Fisher's exact tests (p < 0.05). RESULTS: The prevalence of pulp stones was similar between patient's genders and tooth locations. Pulp stones were detected in 31.9% of patients and 9.5% of teeth. Maxillary and mandibular molars were the groups of teeth with the highest frequency of pulp stones. The presence of restorations increased the chance of occurrence of pulp stones by 2.1 times in all teeth examined (p < 0.0001) and by 4.7 times in maxillary teeth (p < 0.0001). CONCLUSIONS: Pulp stones had a high prevalence with molar teeth showing the highest prevalence. The presence of restorations increased the chance of occurrence of these calcifications, specifically in maxillary teeth. CLINICAL RELEVANCE: CBCT provides accurate anatomical details in three dimensions, offering the possibility to view an individual tooth in axial, sagittal, and coronal views. This study performed an investigation of the occurrence of pulp stones by CBCT.

Effects of auxiliary device use on smear layer removal.

This study evaluated the effects of different auxiliary irrigation devices on smear layer removal with a chelating solution (QMix). Fifty single-rooted permanent human teeth were shaped with a sequence of nickel-titanium instruments. A 2% chlorhexidine gel was used as a chemical auxiliary substance during preparation. Samples were assigned to five groups (n = 10 each) according to final irrigation protocol, namely, distilled water (control group), QMix 1 min, QMix + passive ultrasonic irrigation (PUI), QMix + plastic endodontic finishing file (EC), and QMix 3 min. Teeth were prepared and evaluated by scanning electron microscopy, and three photomicrographs (magnification, 1,000×) were obtained for each root third. Two blinded and precalibrated evaluators analyzed and scored the images, and the data were statistically analyzed by the Kruskal-Wallis and Dunn tests (P < 0.05). Groups were ranked according to the extent of smear layer removal. The total area of the root canal walls and apical root thirds was calculated, and the groups ranked PUI > EC = QMix 3 min > QMix 1 min > control. QMix 1 min was effective for smear layer removal only when used with auxiliary devices, and QMix + passive ultrasonic irrigation yielded the best results, particularly for the apical third.(J Oral Sci 58, 561-567, 2016).

Effectiveness of three methods for evaluating root canal anatomy of mandibular incisors.

This study compared the effectiveness of clinical observation, clinical microscopic observation, and tooth-clearing technique in determining the number of canals in mandibular incisors. Root canal ramifications were also analyzed. Using clinical and microscopic analyses, we determined the number of canal entrances in 277 mandibular incisors. In addition, tooth-clearing technique was used to determine the number of canals and frequency of ramifications in the samples. The kappa coefficient was used to compare the different methods with regard to frequency of canals. Most teeth had one canal entrance. The proportion of teeth with two canals was 23.5% by tooth-clearing analysis, 5.8% by clinical microscopy, and 1.1% by clinical analysis. A large number of samples had some type of ramification (40.1%), and most ramifications were present in teeth with two canals. The most frequent ramification was lateral canals (8.3%). Clinical microscopy improved identification of a second canal in mandibular incisors. However, it did not identify second canals in all teeth with two canals. (J Oral Sci 58, 347-351, 2016).

Push-out Bond Strength of Injectable Pozzolan-based Root Canal Sealer.

INTRODUCTION: The present study aimed to rank the bond strength to root dentin of a new injectable pozzolan-based root canal sealer, EndoSeal MTA, as compared with MTA Fillapex and AH Plus. METHODS: Eighteen dentinal slices (1 ± 0.1 mm) were obtained from the middle third of 6 maxillary incisors previously selected. Three canal-like holes with 0.8 mm diameter were drilled perpendicularly on the axial surface of each slice. Then, a standardized irrigation was applied for all holes that were subsequently filled with 1 of 3 test root canal sealers. After that, slices were stored in contact with phosphate-buffered saline solution (pH 7.2) for 7 days at 37°C before the push-out assay. Friedman test and Wilcoxon signed rank test with a Bonferroni correction were used to rank the results. Significance boundary was set at α = 5%. RESULTS: Friedman test confirmed a significant dissimilarity in push-out ranks among the tested cements (P < .01). Wilcoxon signed rank test demonstrated AH Plus had significant superior resistance to dislodgment compared with Endo Seal (P < .01) or MTA Fillapex (P < .01), whereas MTA Fillapex presented the lowest push-out values as compared with Endo Seal (P < .01) or AH Plus (P < .01). CONCLUSIONS: EndoSeal presents satisfactory bond strength performance for application in endodontic therapy compared with MTA Fillapex, and although it displays a new alternative of injectable bio-tight root canal sealer, it is not able to improve adhesion compared with AH Plus.