The impact of the addition of iodoform on the physicochemical properties of an epoxy-based endodontic sealer

Due to the low radiopacity of Sealer 26, iodoform is frequently empirically added to this sealer. Thus, the interference of this procedure with the physicochemical properties of Sealer 26 must be evaluated. Objective: This study evaluated the influence of the addition of iodoform on setting time, flow, solubility, pH, and calcium release of an epoxy-based sealer. Material and Methods: The control group was pure Sealer 26, and the experimental groups were Sealer 26 added with 1.1 g, 0.55 g or 0.275 g of iodoform. Setting time evaluation was performed in accordance with the ASTM C266-03 speciflcation. The analysis of flow and solubility was in accordance with the ISO 6876-2001 speciflcation. For the evaluation of pH and calcium ion release, polyethylene tubes were filled with the materials and immersed in flasks with 10 ml of deionized water. After 24 h, 7, 14, 21, 28, and 45 days pH was measured. In 45 days, the calcium released was evaluated with an atomic absorption spectrophotometer. Results: The addition of iodoform increased setting time in comparison with pure sealer (P < 0.05). As for flow, solubility, and calcium release, the mixtures presented results similar to pure sealer (p > 0.05). In the 24 h period, the mixture with 1.1 g and 0.55 g of iodoform showed lower pH than pure sealer and than sealer added with 0.275 g of iodoform (P < 0.05). Conclusions: The iodoform added to Sealer 26 interferes with its setting time and solubility properties. Further studies are needed to address the clinical signiflcance of this interference.

Effects of calcium hydroxide addition on the physical and chemical properties of a calcium silicate-based sealer

Recently, various calcium silicate-based sealers have been introduced for use in root canal filling. The MTA Fillapex is one of these sealers, but some of its physicochemical properties are not in accordance with the ISO requirements. Objective: The aim of this study was to evaluate the flowability, pH level and calcium release of pure MTA Fillapex (MTAF) or containing 5% (MTAF5) or 10% (MTAF10) calcium hydroxide (CH), in weight, in comparison with AH Plus sealer. Material and Methods: The flowability test was performed according to the ISO 6876: 2001 requirements. For the pH level and calcium ion release analyses, the sealers were placed individually (n=10) in plastic tubes and immersed in deionized water. After 24 hours, 7 and 14 days, the water in which each specimen had been immersed was evaluated to determine the pH level changes and calcium released. Flowability, pH level and calcium release data were analyzed statistically by the ANOVA test (alpha=5%). Results: In relation to flowability: MTAF>AH Plus>MTAF5>MTAF10. In relation to the pH level, for 24 h: MTAF5=MTAF10=MTAF>AH Plus; for 7 and 14 days: MTAF5=MTAF10>MTAF>AH Plus. For the calcium release, for all periods: MTAF>MTAF5=MTAF10>AH Plus. Conclusions: The addition of 5% CH to the MTA Fillapex (in weight) is an alternative to reduce the high flowability presented by the sealer, without interfering in its alkalization potential.

Signaling Pathways Activation by Primary Endodontic Infectious Contents and Production of Inflammatory Mediators

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação in vitro da resistência estrutural em dentes fragilizados utilizando reforços intra-radiculares

Pós-graduação em Odontologia Restauradora - ICT

Changes in heart period during endodontic treatment

Background: Tooh extraction was demonstrated to increase sympathetic modulation of the heart, however, it is not understood the effects of endodontic treatment on cardiac autonomic regulation. We evaluated heart rate variability (HRV) during endodontic treatment. Method: 50 male and female patients aged between 18 and 40 years old and diagnosed with irreversible pulpitis or pulp necrosis of the lower molars with indication of gender endodontic treatment were analyzed. HRV was analyzed in the time (SDNN, RMSSD, pNN50) and frequency (LF, HF and LF/HF ratio) domains recorded in the first session of root canal treatment. The indices were analyzed in the following periods: T1) ten minutes before the endodontic treatment, T2) ten minutes after the administration of anesthesia before endodontic treatment, T3) during the entire period of endodontic treatment and T4) thirty minutes after the end of the endodontic treatment. Results: The SDNN, RMSSD and pNN50 indices increased at T2 compared to T1, the pNN50 and RMSSD indices increased at T3 and T4 compared to T2. The LF in normalized units increased at T4 compared to T2 and in absolute units it was increased at T4 compared to T1. The HF in normalized units was reduced at T4 compared to T2 and in absolute units was reduced at T1, T3 and T4 compared to T2. The LF/HF ratio was higher at T4 compared to T2. Conclusion: The global modulation of heart increases after local anesthesia and vagal tone reduce during surgery procedures and after the surgical procedures.

Effect of Rotary Instrument Associated with Different Irrigation Techniques on Removing Calcium Hydroxide Dressing

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

18-Year Follow-up of Dens Invaginatus: Retrograde Endodontic Treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Macrophage Cell Activation with Acute Apical Abscess Contents Determined by Interleukin-1 Beta and Tumor Necrosis Factor Alpha Production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tooth Discoloration Induced by Endodontic Phenothiazine Dyes in Photodynamic Therapy

Objective: This study sought to assess if discoloration of tooth structures occurs after photodynamic therapy (PDT) and to determine the efficacy of a protocol to remove the photosensitizers. Background data: PDT has been used in root canal treatment to enhance cleaning and disinfection of the root canal system. PDT uses a low power laser in association with a dye as a photosensitizer. Photosensitizers can induce staining of the dental structures, resulting in an unaesthetic appearance. Methods: Forty teeth were randomly divided into four groups according to the photosensitizer used and pre-irradiation time: 0.01% methylene blue for 5 min (MB5); 0.01% methylene blue for 10 min (MB 10); 0.01% toluidine blue for 5 min (TB5); and 0.01% toluidine blue for 10 min (TB 10). Specimens were irradiated with a 660 nm diode laser with a 300 mu m diameter optical fiber, at 40 mW power setting for 3 min. Immediately after, the photosensitizers were removed with Endo-PTC cream +2.5% sodium hypochlorite (NaOCl). The shade was measured by a Vita Easyshade spectrophotometer based on the CIELAB color system (L*a*b* values) at three different experimental times: before PDT (T0), immediately after PDT (T1), and after removal of the photosensitizer (T2). Results: The results showed a decrease in the averages of the L*a*b* coordinate values after PDT (T1) in all the groups, when compared with the number at T0, with a significant statistical difference in group MB10. After photosensitizer removal (T2), all the values of the coordinates increased with significant statistical differences (p < 0.05) between T1 and T2 in L* and a*. Conclusions: It can be concluded that both methylene blue and toluidine blue dyes cause tooth discoloration, and that Endo-PTC cream associated with 2.5% NaOCl effectively remove these dyes, regardless of the pre-irradiation time used for PDT.

Investigation of chemical changes in sealers during application of the warm vertical compaction technique

Aim To assess (i) heat generated by pluggers during warm vertical compaction of gutta-percha and investigation of temperature changes on the external root surface during canal filling, and (ii) the chemical changes of root canal sealers induced by heat.Methodology Four sealers, namely AH Plus, MTA Plus and two other experimental sealers based on tricalcium silicate, were characterised. External temperatures generated on the root surface during warm vertical compaction of gutta-percha with different sealers inside the root canal were monitored using an infrared thermography camera. Chemical changes induced by heating the sealers were assessed by Fourier transform infrared (FT-IR) spectroscopy.Results MTA Plus and the experimental sealers were composed of a cement and radiopacifier, with epoxy resin or a water-soluble polymer as dispersant, whilst AH Plus was epoxy resin-based. The heat generated at the tips of the continuous wave pluggers was found to be lower than the temperature set and indicated on the device LCD display. The sealers reduced the heat generated on the external root surfaces during the heating phase. AH Plus sustained changes to its chemical structure after exposure to heat, whilst the other sealers were unaffected.Conclusions The temperatures recorded at the tips of continuous wave pluggers varied with their taper and were lower than the temperature set on the System B LCD display. Root canal sealers reduced the dissipation of heat generated during warm vertical compaction, with the temperature at the external root surface maintained at 37-41 degrees C, a temperature below that is necessary to cause irreversible damage to bone and periodontium. The use of AH Plus sealer during warm vertical compaction techniques results in chemical changes in the sealer. The effect on sealer properties needs to be further investigated.

Ação antimicrobiana da clorexidina gel e líquida e do hipoclorito de sódio

The purpose of this study was to evaluate in vitro antimicrobial activity of chlorhexidine gel and liquid 2%, and 2% sodium hypochlorite on Candida albicans, Enterococcus faecalis, Escherichia coli in root canals. For this, we used 40 human single-rooted teeth were divided into 4 groups (n = 10) according to assist the chemical used: 1) 2% chlorhexidine liquid, 2) 2% chlorhexidine gel, 3) sodium hypochlorite 2%, and 4) physiological saline (control). Content were collected immediately after root canal instrumentation and after 7 days of biomechanical. For the samples was conducted to evaluate the antimicrobial activity and the results were subjected to statistical analysis of Kruskal-Wallis and Dunn's test with a significance of 5%. It was found that chlorhexidine gel and liquid as well as sodium hypochlorite were effective against the microorganisms tested

Influência do uso de hipoclorito de sódio 2,5% e extrato glicólico de sálvia 20% durante o preparo biomecânico sobre a resistência adesiva de retentores intra- radiculares: avaliação através do teste de push-out

The aim of this study it was to evaluate the use of irrigating solution used during root canal preparation on the adhesive cementation of prefabricated fiberglass pins. The bond strength between different regions of the root and the fiberglass pins cemented into the root canal were evaluated by push-out assay. For this study, 36 human teeth were used, all equally prepared. The irrigating solutions used for biomechanical preparation were: saline solution, sodium hypochlorite 2,5% and glycolic extract of salvia 20%. The dual cure resin cement was used for cementation of pins. After cementation, specimens were sectioned to give 3 slices of approximately 2 mm each (cervical, middle and apical), which were submitted to mechanical push-out test. Were performed ANOVA and Tukey's test with a significance level of 5%, for the analysis of mechanical test. Comparing the thirds we observed that the only solution that presented statistical difference in the bond strength was sodium hypochlorite, which showed higher values for the middle and apical third compared with the cervical third, but when compared without taking into consideration the dental thirds, solutions studied showed no differences in bond strength. Therefore, it was concluded that the solutions studied can be used during endodontic treatment without causing harmful effects on the final adhesive restoration

Avaliação in vitro da ação de substâncias químicas auxiliares, clorexidina e medicações intracanais sobre C. albicans, E. faecalis, E. coli e sua endotoxina em canais radiculares: [recurso eletrônico]

The purpose of this study was to evaluate the antimicrobial activity of chlorhexidine gel 2% as auxiliary chemical substance on the biomechanical preparation (BMP) and medication intracanal (ICM) on C. albicans, E. faecalis, E. coli and their endotoxin in root canals. We used 48 single-rooted human teeth divided into four groups according to dressing ICM: 1) Ca(OH)2 + pyrogen-free saline solution; 2) 2% chlorhexidine gel (CLX); 3) Ca(OH)2 + CLX, and; 4) pyrogen-free saline solution (control group). Were collected the contents of root canals to confirm the presence of microorganisms (confirmation), immediately after instrumentation (1st collection), after 7 days of the BMP (2nd collection), after 14 days of the action of ICM (3rd Collection) and 7 days after removal of the ICM (4 th collection). Were performed: the evaluation of antimicrobial activity and the content analysis of endotoxins for all sampling tests. The results were statistically analyzed using Kruskall-Wallis and Dunn tests with a significance of 5%. It was found that the CLX as auxiliary chemical substance has significantly reduced microorganisms confirmation collection when compared. In relation to the neutralization of endotoxin, it was found that the 1st and 2nd collections presented a decrease of 92.03% and 98.10% in mean percentage respectively, when compared to the confirmation collection. In the 3rd and 4th samplings, the Ca (OH)2 + CLX group showed the best results. It was concluded that the BMP and the ICM were able to eliminate the tested microrganisms, however, they were not able to completely eliminate endotoxins root canal

Estudo da anatomia interna dos incisivos laterais superiores pelos métodos radiográficos digital e convencional

The maxillary lateral incisor has a very peculiar and internal morphology that can be influenced by the its external anatomy such as supernumerary roots and ruts deep root, which often hinders an effective endodontic treatment. Generally, this tooth have a single root with one root canal, but teeth with two to four channels can be found. The main canal can present ramifications such as accessory canals, laterals, collaterals, recorrents and apical deltas. All this factors interfere directally on endodonthics treatment. The objective of this work is a study of the internal anatomy of the maxillary lateral incisors by digital and conventional radiographics methods, comparing the results obteined by each method Six hundred upper lateral incisor were used in this study teeth of the collection of the Department of Anatomy ICT – UNESP. All the teeth were radiographed by vestibular face, using a digital radiographic unit(Dabi Atlante). After this step, all the teeth underwent by conventional radiographic technique(Kodak 2200) so that the results obtained were compared. To classify the channel system, it was adopted the classification of Pucci and Reig. All data obtained by digital technique were compared with those obtained in the conventional technique and were subjected to statistical analysis