Morphometric parameters of dental pulp in immature teeth in a sheep model after mechanical pulp exposure and restoration with reinforced zinc oxide-eugenol.

Background: The aim of the study was to investigate the morphometric parameters of dental pulp in open apices immature teeth in a sheep model after mechanical pulp exposure and restoration with reinforced zinc oxide-eugenol. Materials and Methods: In this experimental study, a total of 12 immature mandibular central incisors from six adult male sheep, weighing 30-40 kg and with the age of 1 year old with Merino race were examined. After anesthesia, the pulps of the teeth in the case group were mechanically exposed and then were restored with reinforced zinc oxide-eugenol and amalgam. In the control group, the teeth remained intact. The animals were sacrificed at intervals of 2, 4, 6, and 8 weeks (E2, E4, E6, and E8) in the case and 2 and 8 weeks (C2 and C8) in the control groups. Then, their teeth were removed with the surrounding supporting tissues and alveolar bones. Tissue processing and staining were done, and the sections were examined under a light microscope. The Kruskal-Wallis and Mann-Whitney U tests were used to analyze the data and compare the changes between the two groups. P < 0.05 was considered statistically significant. Results: In response to mechanical exposure, reparative or tertiary dentin was formed, and its thickness increased during the time of the study. The thickness of the odontoblastic layer in the E4 group was the highest amount. The pulp chamber diameter in the C2 group was significantly larger than the other groups, and the diameter of the apical foramen in the E8 was decreased significantly compared to the controls (P < 0.05). Conclusion: In response to mechanical exposure and restoration with reinforced zinc oxide-eugenol, some morphometric parameters of the dental pulp changed significantly in the sheep model compared to the controls.

Efficacy of orthoMTA, retroMTA and ferric sulphate as pulpotomy agents in primary molars: a randomized clinical trial.

Purpose: The purpose of this study is to evaluate the clinical and radiographic success rates of RetroMTA, OrthoMTA, and ferric sulfate as pulpotomy agents in primary molars. Materials and methods: Ninety-six primary second molars from 32 children aged 5 to 9 years were enrolled in this study. The teeth were randomly divided into three groups based on the pulpotomy agent used: O-MTA, R-MTA, and FS. Clinical and radiographic follow-up examinations were conducted at 3, 6, 9, and 18 months postoperatively. Results: At the end of the study period, 84 teeth were evaluated. The clinical success rates were 75% for FS, 96.4% for O-MTA, and 92.8% for R-MTA groups. In the radiographic analysis, the success rates at the 18-month follow-up period were 50% for FS, 85.8% for O-MTA, and 82.2% for R-MTA groups. According to the Chi-square test and Kaplan-Meier survival analysis, there was a statistically significant difference among the success rates and survival probabilities of the groups (p<0.05). Conclusion: OrthoMTA and RetroMTA demonstrated better treatment outcomes for pulpotomy of primary second molars than ferric sulfate at the 18-month follow-up period.

Comparison of physico-chemical properties of zinc oxide eugenol cement and a bioceramic sealer.

The aim of the present study was to compare the physico-chemical properties of EssenSeal with AH PLUS bioceramic and Pulp Canal Sealer EWT. Flow, solubility, film thickness, radiopacity and setting time were evaluated according to ISO 6876 (2012) specifications. External and cross-section surface characteristics were analysed under a scanning electron microscope. Statistical analysis was performed using Shapiro-Wilk's test, one-way ANOVA and the Tukey HSD test. All the sealers conformed to the ISO 6876 (2012) standards, except for the setting time for AH plus bioceramic, which exceeded more than 10% of the time indicated by the manufacturer. Statistically significant differences were found between the three study sealers regarding the physico-chemical properties tested (p < 0.05). EssenSeal demonstrated characteristics respecting the ISO 6876 (2012) standards and can be considered a predictable alternative in root canal sealing.

The effectiveness of EDTA 17% as a cleaning solution for the fiber post space after filling with cements

Aim: To evaluate the resistance of the union between a glass fiber post and radicular dentine after cleaning the root with 17% EDTA and filling with different endodontic cements. Methods: Forty uniradicular bovine incisors were removed to obtain root lengths of 18 mm. Endodontic treatment was performed on all roots using different filling cements (zinc oxide and eugenol-based, OZE; cement based on epoxy resin, AH) and cleaning solutions (saline, SA or EDTA), which made it possible to obtain four groups: OZESA, OZEEDTA, AHSA and AHEDTA. Subsequently, 12 mm of filling material was removed from the roots, and they were prepared to receive fiber posts luted with resin cement. To execute the mechanical cycles (2x106 cycles, 90 N, 4 Hz), coronal reconstruction was performed with a silicon matrix. The roots were then sliced (2-mm thick) to perform the push-out test. The results were analyzed using analysis of variance (one factor and two factors) and Tukey's test (α=0,05). Results: Bond strength (Mpa) was significantly higher for OZEEDTA (9,18) and AHEDTA (8,70) than for OZESA (6,06) AHSA (8,7). OZEEDTA also presented the highest values in the cervical region (15,18) but was significantly lower in the apical region (2,99). However, AHEDTA had a homogeneous bond strength in all thirds. Conclusion: Regardless of the endodontic cement used, EDTA was used as an irrigating solution, culminating in a higher bond strength between the glass fiber post and dentin

Infiltration by Streptococcus mutans in provisional crowns fixed by two types of cementing agents ­ pilot double-blind randomized clinical trial / Infiltração por Streptococcus mutans em coroas dentárias provisórias fixadas por dois tipos de agentes cimentantes ­ estudo clínico randomizado duplo-cego piloto

Objective: When provisional acrylic crowns are used for a long time, they become more susceptible to marginal leakage by cariogenic bacteria. The objectives of this pilot clinical study were to compare cement based on zinc oxide-eugenol and calcium hydroxide by contamination with Streptococcus mutans, and calculate the sample size for the continuation of this study. Methods: Individuals receiving provisional crowns and following inclusion/exclusion criteria, were randomly distributed into 2 groups: zinc oxide-eugenol (n=8); calcium hydroxide (n=9). The temporary crowns were made by a blind researcher and cemented by another. Patients were also blinded by the cement used inside their crowns. After 2 months, a cement sample from the crowns' peripheral inner face was collected, placed in a tube containing 1 mL of sterile saline, serially diluted, plated on Mitis Salivarius Bacitracin agar, and incubated for 48 hours. Colony-forming units (CFU/mL) were counted. A statistical power analysis was performed to calculate sample size (1-ß=80%) and the Mann Whitney test to compare both cements (α=0.05). Results: Both cements were contaminated with S. mutans, with an average of 166.6 x 102 CFU/mL for calcium hydroxide and 435.3 x 102 CFU/mL for zinc oxide-eugenol, with no significant difference (p=0.311). The sample size calculated for this study was 36 per group. Conclusion: This pilot study suggests that there is important contamination inside provisional crowns used for two months, independent of the cement. The continuation of this study is needed, with a bigger sample size, to enable a comparison between the cements.

Objetivo: Quando coroas dentais provisórias são utilizadas por um longo período, elas se tornam susceptíveis à infiltração marginal por bactérias cariogênicas. O objetivo deste estudo clínico piloto foi comparar os cimentos a base de óxido de zinco e eugenol e hidróxido de cálcio pela contaminação com Streptococcus mutans e calcular o tamanho amostral para continuação deste estudo. Métodos: Indivíduos recebendo coroas provisórias e seguindo critérios de inclusão/exclusão, foram distribuídos aleatoriamente em dois grupos: óxido de zinco e eugenol (n=8); hidróxido de cálcio (n=9). As coroas provisórias foram feitas por um pesquisador cego e cimentadas por outro. Os pacientes também foram cegos quanto ao cimento utilizado dentro de suas coroas. Depois de 2 meses, amostras de cimentos foram coletadas da face interna periférica das coroas, colocadas em um tubo contendo 1 mL de solução salina estéril, diluídas de forma seriada, plaqueadas em ágar Mitis Salivarius Bacitracina e incubadas por 48 horas. Unidades formadoras de colônias (UFC/mL) foram contadas. Um teste de poder estatístico foi realizado para calcular o tamanho amostral (1-ß=80%) e o teste de Mann Whitney para comparar os dois cimentos (α=0.05). Resultados: Os dois cimentos foram contaminados com S. mutans, com uma média de 166.6 x 102 UFC/mL para o hidróxido de cálcio e 435.3 x 102 UFC/mL para o óxido de zinco e eugenol, com nenhuma diferença significativa (p=0.311). O cálculo amostral para este estudo foi 36 indivíduos por grupo. Conclusão: Este estudo piloto sugere que existe importante contaminação dentro de coroas provisórias utilizadas por 2 meses, independente do cimento. A continuação deste estudo é necessária, com maior tamanho amostral, para possibilitar a comparação entre os cimentos.

The effect of smear layer on bacterial penetration through roots obturated using zinc oxide eugenol-based sealer.

BACKGROUND: Smear layer removal has been shown to reduce bacterial penetration through root canal obturations when resin-based endodontic sealer is used. The purpose of this in vitro study was to test this effect when a non-resin-based sealer is used. MATERIAL AND METHODS: Thirty root segments were assigned to the following groups: Smear layer removed (n = 8); smear layer retained (n = 8); negative controls (n = 10; 5 with smear layer, 5 without); and positive controls (n = 4; 2 with smear layer, 2 without). After rotary instrumentation, smear layers were removed in the treatment group and half of controls using 17% ethylenediamenetetraacetic acid (EDTA) prior to obturation. Each obturated root was affixed into a dual-chamber leakage model employing Streptococcus mutans. Roots were incubated at 37 °C for 120 d. Days until lower chamber turbidity occurred was recorded for each sample, and data were analyzed using Kaplan-Meier survival curve analysis (p = 0.05). RESULTS: No negative controls leaked, while all positive controls were turbid within 1 day. Mean days to leakage for roots with smear layer intact was 82.75 (+/- 33.29, 95% CI), although three never leaked. Mean days to leakage through roots with smear layer removed was 46.25 (+/- 26.67, 95% CI), and all leaked. Treatment survival curves were significantly different (p = 0.048). CONCLUSIONS: Under the conditions and limitations of this study, retaining the smear layer reduced the rate of bacterial penetration through canals which had been obturated using zinc oxide eugenol (ZOE) -based sealer.

Digital Radiographic Evaluation of the Quality of Different Root Canal Obturation Techniques in Deciduous Mandibular Molars after Preparation with Rotary Technique.

STATEMENT OF THE PROBLEM: Several factors affect the success of pulp therapy of primary teeth, including cleaning and shaping of the root canals and the quality of obturation as the most important steps. PURPOSE: The aim of the present study was to compare the quality of different root canal obturation techniques in deciduous mandibular molars subsequent to preparation of the root canals with the rotary technique, using the photo stimulated phosphor (PSP) digital radiographic technique. MATERIALS AND METHOD: In this in vitro study, 221 root canals were selected in 80 extracted deciduous mandibular second molars. The root canals were prepared with a modified protocol for ProTaper NiTi rotary files and with only two instruments (SX and S2) and obturated using a lentulo spiral, condensation technique, an anesthetic syringe, and tuberculin syringe techniques with ZOE paste. The quality of the root canal obturation (obturation length and the number and sizes of the voids) was evaluated using PSP radiographic technique. Data were analyzed with SPSS 21, using chi-squared, Kruskal-Wallis and Mann-Whitney tests. RESULTS: There were no significant differences in the obturation length (p= 0.285) and the number of voids (p= 0.061) between the study groups; however, there were significant differences in void sizes between the study groups (p= 0.001). The condensation and tuberculin syringe groups exhibited the best and worst results considering the obturation length, respectively. Lentulo and anesthetic syringe techniques have also exhibited acceptable results. The condensation and anesthetic syringe groups exhibited the minimum and maximum number of voids, respectively. The condensation and lentulo groups exhibited the maximum and minimum void sizes, respectively. CONCLUSION: If implemented correctly, there will be no significant difference among the experienced root canal obturation techniques considering obturation length and the number of voids.

Effect of Root Canal Sealers on Bond Strength of Fiber Posts to Root Dentin Cemented after one Week or six Months.

Eugenol-based root canal sealers (RCS) have been widely used by clinicians; however, their effect on resinous materials is still questionable. The objective of this study was to evaluate the influence of RCS at 1 week and 6 months' post obturation on the bond strength (BS) of glass fiber posts (GFP) to root dentin, using conventional and self-adhesive cementation systems (CS). The roots of 56 extracted human canines, were divided in eight groups (n=7) according to the combination of the following factors: RCS (with or without eugenol-Endofill and Sealer 26, respectively), storage period post obturation and prior GFP cementation (1 week and 6 months) and cementation systems (Variolink II - conventional resin cement or RelyX U200-self-adhesive resin cement). After one week, the specimens were transversely sectioned into six 1-mm-thick disks and were subjected to the push out BS test. The data were subjected to 3-way ANOVA and Tukey's tests (α=0.05). The BS were not affected by the RCS, neither the CS (P>0.05). Just the period post obturation showed statistically significant differences (P 0.05), where the GFP cemented 6 months after the endodontic treatment showed higher values than those cemented 1 week after it.

Push-out bond strength of different intracanal posts in the anterior primary teeth according to root canal filling materials.

BACKGROUND: This study was carried out to evaluate the effect of root canal filling on the bond strength of three intracanal posts in the primary incisors. MATERIALS AND METHODS: Sixty primary incisors were prepared and then divided into two groups (n = 30). The first group canals obturated with zinc oxide eugenol (ZOE) and Group 2 canals obturated with Metapex. Further, the two group categories were divided into three subgroups (n = 10): (1) short composite post (SCP), (2) glass fiber posts (GFPs) cemented with flowable composite, and (3) GFP with glass ionomer cement (GFP + GIC). The push-out test was performed with a universal testing machine. The results were statistically analyzed with two-way analysis of variance.(α = 0.05). RESULTS: The mean bond strength of the first group obturated with ZOE was lower than that of the second group obturated with Metapex (P = 0.046). Moreover, from a statistical point of view, in all three subgroups, the correlation of mean push-out bond strength between SCP and GFP coated with flowable composite was not substantial at P = 0.97. However, the mean bond strength of SCP was in fact significantly greater than that of the GFP coated with GIC since P = 0.034. CONCLUSION: Using ZOE resulted in the significant reduction of the mean bond strength of the intracanal posts when utilized in the primary anterior teeth. Likewise, SCP and GFP coated with flowable composite showed higher push-out bond strengths for restoring primary anterior teeth.

In Vitro Comparative Evaluation of Cleaning Efficacy and Volumetric Filling in Primary Molars: Cone Beam Computed Tomography Evaluation.

INTRODUCTION: Pulpectomy of primary teeth is mostly carried out with hand files and broaches which is tricky and time consuming procedure. The development of new design features like varying tapers, non-cutting safety tips and varying length of cutting blades have resulted in new generation of rotary instruments. AIM: To compare and evaluate cleaning efficacy, canal preparation and volumetric filling using conventional files and rotary V Taper files through cone beam computed tomography. MATERIALS AND METHOD: Thirty extracted primary molars were selected. The teeth were randomly divided into three groups each containing 10 teeth i.e. 30 canals in each group. Group A was instrumented with K files; Group B rotary V Taper files and Group C was Hybrid group. Sodium hypochlorite (1%) was used for irrigation. Root canal filling was done with Zinc Oxide Eugenol cement in all groups. The volumetric analysis i.e. Percentage of Volume (POV) of the root canal filling in primary molars was done through CBCT Software. RESULT: In present study, p- value was found to be significant (<0.05). Almost 100% of canals of hybrid group were fully filled and 63.3% of canals of hand filing group were partially filled. The filling was found to be dense and no. of voids was least in hybrid group. CONCLUSION: Clinical time required in primary molar endodontics, especially with unpredictability and difficulty of canal morphology, is inevitable. The study confirms superior ability of rotary-file systems to shape severely curved canals with less time and significant decrease in procedural errors like partial filling, voids and inappropriate canal preparation.

Antimicrobial Efficacy of Mixtures of Nanosilver and Zinc Oxide Eugenol against Enterococcus faecalis.

AIM: This study aimed to assess the antimicrobial efficacy of 0, 0.5, 2, and 5 wt% nanosilver in conjunction with zinc oxide eugenol (ZOE) against Enterococcus faecalis. MATERIALS AND METHODS: Nanosilver in 0.5, 2, and 5 wt% concentrations was added to ZOE and the antibacterial activity of the mixtures on E. faecalis was assessed using disk diffusion method, and the results were reported as the diameter of the growth inhibition zone. RESULTS: The diameters of the growth inhibition zones around 0, 0.5, 2, and 5 wt% concentrations of nanosilver particles were not significantly different at 24 and 48 hours and 1 week; however, the difference with the azithromycin disk was significant. CONCLUSION: Considering the lack of a significant increase in the diameter of the growth inhibition zones around 0, 0.5, 2, and 5 wt% ZOE containing nanosilver, it appears that addition of nanosilver up to 5 wt% cannot improve the antibacterial properties of ZOE sealer against E. faecalis. CLINICAL SIGNIFICANCE: Microorganisms present in the root canal system of primary teeth are mainly responsible for endodontic infections. Enterococcus faecalis is the most important cause of endodontic failure. Application of sealers that decrease the adhesion and colonization of bacteria, as well as susceptibility to bacterial infections can greatly help in this regard. Using these sealers in conjunction with antibacterial agents, such as nanosilver particles may yield higher antibacterial efficacy.

In vitro antimicrobial effect of different root canal sealers against oral pathogens.

BACKGROUND AND PURPOSE: Root canal therapy is the primary method for the treatment of an infected pulp in modern dentistry. The main aim of endodontic treatment is the elimination of bacteria and their products from infected root canals. In this study, we attempted to investigate the antimicrobial activity of three root canal sealers against oral pathogens. MATERIALS AND METHODS: The antimicrobial effectiveness of three endodontic sealers with different chemical compositions, namely resin (AH 26), zinc oxide eugenol (ZOE), and mineral trioxide aggregate (MTA), against Candida albicans, Streptococcus sanguis, Streptococcus salivarius, Streptococcus mutans, and Lactobacillus casei was assayed by agar well diffusion method (AWDM). The tested sealers were prepared according to the manufacturer's instructions and poured in the prepared wells of agar plates; diluted inocula (105 and 106 CFU/ml) of the tested microorganism strains were also used. The minimum inhibitory concentration (MIC) values of the selected canal sealers ranged between 3.12 and 50 mg.ml-1 against the employed microorganism strains. All the plates were incubated at 37°C under anaerobic condition for bacteria and at 30°C for C. albicans. After three days, the inhibition zones were measured. RESULTS: In this investigation, AH 26 exhibited strong activity against C. albicans with the minimum inhibitory concentration of 12.5 mg.ml-1, but ZOE and MTA did not act against C. albicans. ZOE sealer had the highest antimicrobial activity against the tested bacteria, while MTA showed the lowest antimicrobial activity. CONCLUSION: The ascending sequence of microbial growth inhibition zones was as follows AH 26 > ZOE > MTA.

Fate of pulpectomized deciduous teeth: Bilateral odontogenic cyst?

Pulpectomy is preferably more conservative treatment option than the extraction of deciduous teeth despite few undesirable consequences of obturating materials of which odontogenic cysts are one. This article aims to report a case of an 11-year-old female child having bilateral odontogenic cysts, i.e., radicular and infected dentigerous cyst followed by pulpectomy of deciduous molars using zinc oxide eugenol which was surgically enucleated and followed up to 6 months until satisfactory healing of bone was observed. The article also emphasizes on the importance of regular follow-up of the pulpectomized tooth which can be harmful otherwise.

Influence of temporary cement in the tensile strenght of fullcrowns cemented with resin cement / Influência do cimento temporário na resistência à tração de coroas totais cimentadas com cimento resinoso

Objetivo: Este estudo avaliou a influência do eugenol residual a resistência à tração na cimentação decoroas cerômero, usando cimento resinoso. Material e Métodos: Trinta e nove terceiros molares foram preparados para coroa total. Para cada dente preparado uma restauração provisória e uma coroa de cerômero foram feitas. Os dentes foram divididos em três grupos de acordo com o cimento provisório (n = 13): [GTB]Temp de Bond; [GTBNE] Temp NE Bond e [GDY] Dycal. Após a cimentação temporária, os dentes foram mantidos em água destilada por uma semana e, em seguida, submetidos ao teste de tração em uma máquina universal de ensaios (EMIC DL 500), usando uma célula de carga 200 kgf em 0,5 mm/min. Após o teste, os dentes foram limpos e receberam a cimentação adesiva final das coroas de cerômero. Em seguida, as amostras foram mantidas em água destilada (37 ºC) durante uma semana e, em seguida, foi realizado o teste de resistência à tração, também a 0,5 mm/ min. A comparação entre grupos foi realizada por análise de variância (ANOVA)seguida pelo teste de Tukey (p < 0,05). Resultados: Os resultados (kgf) de cimentação provisória para grupos GTB, GTBNE e GDY foram respectivamente: 2,75 ± (1.35b), 3,43 ± (1.66ab), e 4,48 ± (1.11a).Os resultados da cimentação adesiva (Kgf) eram respectivamente: 42,71 ± (15.33b), 57,59 ± (15.66a),e 54,75 ± (15.28ab). Conclusão: Concluiu-se que o cimento temporário, contendo eugenol apresentou influência negativa sobre a resistência à remoção de coroas cimentados com cimento de resinoso. Além disso, o dycal apresentou melhor resistência à remoção.

Objectives: This study evaluated the influenceof residual eugenol on the tensile strength in the ceromer crowns cementation, using resin cement. Material and Methods: Thirty-nine third molarswere prepared for a full crown. For each prepared tooth one provisional and one ceromer crown were made. The teeth were divided into three groups according the temporary cement (n = 13): [GT]Temp Bond; [GTBNE] Temp Bond NE and [GDY]Dycal. After temporary cementation, the teeth were kept in distilled water for one week and then submitted to traction test in a universal testing machine (EMIC DL 500), using a 200 Kgf loadcell at 0.5 mm/min. After the test, the teeth werecleaned and received the final adhesive cementationof ceromer crowns. Next, the specimens were keptin distilled water (37 0C) for a week and then the tensile strength test was performed, also at 0.5 mm/min. The comparison among groups was carriedout by variance analysis (ANOVA) followed by theTukey test (p ≤ 0.05). Results: The results (Kgf)of provisional cementation for groups GTB, GTBNEand GDY were respectively: 2.75 ± (1.35b), 3.43± (1.66ab), and 4.48 ± (1.11a). The results of the adhesive cementation (Kgf) were respectively:42.71 ± (15.33b), 57.59 ± (15.66a), and 54.75 ±(15.28ab). Conclusion: It was concluded that the temporary cement containing eugenol presented negative influence on the removal resistance of crowns cemented with resin cement. Furthermore,dycal presented best result for removal resistance.

Effect of the type of endodontic sealer on the bond strength between fiber post and root wall dentin.

OBJECTIVES: An important factor that interferes with the bonding between the root canal wall and resin cement is the root canal sealer remnant. There is controversy about the effect of eugenol-containing sealers on the bond strength between resin cements and fiber post. The aim of this study was to evaluate the effect of the type of endodontic sealer on the bond strength of FRC posts cemented with resin cement to the root canal wall. MATERIALS AND METHODS: In this in vitro study, 20 extracted mandibular first premolars were endodontically treated and divided into two groups according to the endodontic sealer used (n=10): G1: AH26 (Resin based); and G2: Endofill (Eugenol-based). After preparing post space, adhesive resin cement (Panavia F 2.0) was used for cementation of the fiber post to the root canal dentin. Three 3 mm thick slices were obtained from each root. The push-out test was performed with a cross-head speed of 1 mm/minute. Two-way ANOVA and Tukey post hoc tests were used for analyzing data (α=0.05). RESULTS: The two-way ANOVA showed that different root canal sealers (P=0.037) had significant effects on bond strength (BS), but root canal regions (P=0.811) and interaction between root canal sealers and root canal regions (P=0.258) had no significant effects on BS. Maximum and minimum mean values were observed in the AH26 group, the apical region and the Endofill group in the apical region, respectively. Post Hoc Tukey test revealed that there were no significant differences between different root canal regions in both cements (P>0.05). CONCLUSION: The region of root canal had no effect on the bond strength of cemented fiber posts to the root canal. Eugenol-based sealers (Endofill) significantly reduced the bond strength between fiber posts luted with resin cement to the root canal.

Efficacy of various cleansing techniques on dentin wettability and its influence on shear bond strength of a resin luting agent.

PURPOSE: To evaluate the shear bond strength of resin luting agent to dentin surfaces cleansed with different agents like pumice, ultrasonic scaler with chlorhexidine gluconate, EDTA and the influence of these cleansing methods on wetting properties of the dentin by Axisymmetric drop Shape Analysis - Contact Diameter technique (ADSA-CD). MATERIALS AND METHODS: Forty coronal portions of human third molar were prepared until dentin was exposed. Specimens were divided into two groups: Group A and Group B. Provisional restorations made with autopolymerizing resin were luted to dentin surface with zinc oxide eugenol in Group A and with freegenol cement in Group B. All specimens were stored in distilled water at room temperature for 24 hrs and provisional cements were mechanically removed with explorer and rinsed with water and cleansed using various methods (Control-air-water spray, Pumice prophylaxis, Ultrasonic scaler with 0.2% Chlorhexidine gluconate, 17% EDTA). Contact angle measurements were performed to assess wettability of various cleansing agents using the ADSA-CD technique. Bond strength of a resin luting agent bonded to the cleansed surface was assessed using Instron testing machine and the mode of failure noted. SEM was done to assess the surface cleanliness. Data were statistically analyzed by one-way analysis of variance with Tukey HSD tests (α=.05). RESULTS: Specimens treated with EDTA showed the highest shear bond strength and the lowest contact angle for both groups. SEM showed that EDTA was the most effective solution to remove the smear layer. Also, mode of failure seen was predominantly cohesive for both EDTA and pumice prophylaxis. CONCLUSION: EDTA was the most effective dentin cleansing agent among the compared groups.

Efficacy of various cleansing techniques on dentin wettability and its influence on shear bond strength of a resin luting agent

PURPOSE: To evaluate the shear bond strength of resin luting agent to dentin surfaces cleansed with different agents like pumice, ultrasonic scaler with chlorhexidine gluconate, EDTA and the influence of these cleansing methods on wetting properties of the dentin by Axisymmetric drop Shape Analysis - Contact Diameter technique (ADSA-CD). MATERIALS AND METHODS: Forty coronal portions of human third molar were prepared until dentin was exposed. Specimens were divided into two groups: Group A and Group B. Provisional restorations made with autopolymerizing resin were luted to dentin surface with zinc oxide eugenol in Group A and with freegenol cement in Group B. All specimens were stored in distilled water at room temperature for 24 hrs and provisional cements were mechanically removed with explorer and rinsed with water and cleansed using various methods (Control-air-water spray, Pumice prophylaxis, Ultrasonic scaler with 0.2% Chlorhexidine gluconate, 17% EDTA). Contact angle measurements were performed to assess wettability of various cleansing agents using the ADSA-CD technique. Bond strength of a resin luting agent bonded to the cleansed surface was assessed using Instron testing machine and the mode of failure noted. SEM was done to assess the surface cleanliness. Data were statistically analyzed by one-way analysis of variance with Tukey HSD tests (alpha=.05). RESULTS: Specimens treated with EDTA showed the highest shear bond strength and the lowest contact angle for both groups. SEM showed that EDTA was the most effective solution to remove the smear layer. Also, mode of failure seen was predominantly cohesive for both EDTA and pumice prophylaxis. CONCLUSION: EDTA was the most effective dentin cleansing agent among the compared groups.

Avaliação da Influência do Eugenol na Infiltração Marginal em Restaurações de Resina Composta em Dentes Decíduos / Evaluation of the Influence of Eugenol in Dental Leakage in Composite Resins Restorations in Deciduous Teeth

Objetivo: Avaliar a infiltração marginal em restaurações de resina composta, realizadas sobre forramento com óxido de zinco e eugenol em molares decíduos.Método: Foram utilizados 24 molares decíduos divididos em três grupos (n=8/grupo), de acordo com o tempo decorrido até a realização da restauração de resina. G1= imediatamente após inserção do IRM;G2= após 48h e G3= após 28 dias. Uma cavidade oclusal foi realizada em cada dente com ponta montada diamantada 3018 HL. Depois de restaurados, os dentes foram cobertos por uma camada de esmalte e cera, deixando-se livre uma região de 1 mm ao redor da restauração. Os dentes foram, então, imersos no corante rodamina a 0,5% durante 24h. As amostras foram cortadas em máquina de corte (Labcut 1010), avaliadas em Estéreo Microscópio e classificadas por níveis de infiltração de 0 a 3. Os resultados foram submetidos aos teste KruskallWallis e Qui-Quadrado, com nível de significância de 5%. Resultados: Constatou-se significativa associação entre infiltração e período decorrente até a realização da restauração. No período imediato houve menor grau de infiltração enquanto no período de 28 dias houve maior grau de infiltração (p=0,02). Conclusão: É importante que não haja muito tempo entre restauração provisória com IRM e restauração definitiva com resina composta a fim de diminuir a infiltração marginal

Objective: to evaluate dental leakage in composite resin restorations carried through on the lining with zinc oxide and eugenol in molar deciduous. Methods: For the study, had been used 24 deciduous molars, which had been divided in three groups, in accordance with the moment where the resin restoration was carried through: G1= immediately after de insertion of the IRM, G2= after 48 hours and G3= after 28 days. A occlusal socket was carried through, in all the teeth, with a drill 3018 HL (KG Sorensen). After restored, the teeth had been covered enamel layer and wax, leaving itself around exempts a region of 1,, of the restoration. The teeth had been, then, immersed in rodamina dye 0.5% during 24 hours. After it was removed the enamel and the wax, and the teeth had been washed, dried and cut with a machine of precision cut (Labcut 1010). The specimens had been evaluated in a Stereo Microscope (Olympus SZH 10) and classified by levels of infiltration of 0 the 3. Results: Through the analysis statistics, a significant association was evidenced enters the presence of infiltration and the period where the restoration was carried through. It was observed that in the immediate period dental leakage had a minor and in the period of 28 days a bigger infiltration (p=0.02). Conclusion: It is important that there is not much time between temporary restoration with IRM and final restoration with composite resin to decrease microleakage

Effect of eugenol-based endodontic sealer on the adhesion of intraradicular posts cemented after different periods

OBJECTIVE: This study evaluated in vitro the influence of an eugenol-based sealer (EndoFill) on the retention of stainless steel prefabricated posts cemented with zinc phosphate and resin-based (Panavia F) cements after different periods of root canal obturation, using the pull-out test. MATERIAL AND METHODS: Sixty upper canines were decoronated and the roots were embedded in resin blocks. The specimens were distributed into 3 groups, according to the period elapsed between canal obturation and post cementation: Group I - immediately; Group II - 72 h and Group III - 4 months. The groups were subdivided according to the type of cement used for post cementation: A - zinc phosphate and B - Panavia F. Following the experimental periods, specimens were subjected to pullout test in an Instron machine with application of tensile force at a crosshead speed of 0.5 mm/min until post dislodgement. The maximum forces required for post removal were recorded (kN) and means were subjected to statistical analysis by 2-way ANOVA and Tukey-Kramer test (á=0.001) RESULTS: There were statistically significant differences (p<0.01) between the posts cemented with zinc phosphate cement (0.2112 kN) and Panavia F (0.0501 kN). However, no statistically significant differences (p>0.05) were found between the three post cementation periods, regardless of the cement. CONCLUSIONS: It was concluded that the eugenol-based sealer influenced the tensile strength of the posts cemented with the resin cement, but had no influence on the time waited between root canal obturation and post space preparation/post cementation.

Microfiltración apical in vitro de tres cementos utilizados en la obturación de conductos radiculares / In vitro apical microleakage of three cements used in the filling of root canals

El propósito de este estudio fue comparar la microfiltración apical in vitro obtenida por los cementos de obturación a base de óxido de zinc-eugenol (Endofill®), resina epóxica (AH-Plus®) y trióxido de minerales agregados (Endo CPM Sealer®). Se prepararon 165 piezas dentarias unirradiculares recientemente extraídas y donadas para el estudio, de conducto único y de Clase I según la clasificación de Zidell, divididas en tres grupos de 53 piezas dentarias por cada cementoy dos grupos control de tres piezas cada uno. Los controles positivos fueron piezas sin obturar y permeables los dos milímetros más apicales, mientras que a los controles negativos no se les instrumentó, solo se les impermeabilizó con barniz de uñas. Todas las piezas fueron sumergidas en tinta china, luego fueron descalcificadas y diafanizadas. La microfiltración apical fue medida cada 0,5mm lineales utilizando un estereomicroscopio. Se encontró diferencia estadísticamente significativa entre los tres grupos de cementos selladores (p < 0,01). Presentaron de mayor a menor microfiltración el cemento a base de óxido de zinc-eugenol (Endofill®), trióxido deminerales agregados (Endo CPM Sealer®) y resina epóxica (AH-Plus®) respectivamente.

The purpose of this study was to compare the apical microleakage in vitro obtained by canal sealers based on zinc oxide eugenol (Endofill®), epoxy resin (AH-Plus®) and mineral trioxideaggregate (Endo CPM Sealer®). One hundred sixty five single rooted freshly extracted teeth and class I according to Zidell classification were prepared, divided in three groups of fifty three sampless and two control groups of three root canals each. The samples of the positive control group were not filled and the samples of the negative control group were not instrumented, notfilled and coated with nail varnish. All the specimens were inmersed in India ink and posteriorly were descalcified and cleared. Apical microleakage was measured in lineal millimeters with the use of a stereo microscope. Significant statistical differences were found between the three canals sealers (p less than 0.01). The apical microleakage was from higher to lower: 1) zinc eugenol based canal sealer, 2) MTA based canal sealer and 3) resin based canal sealer.