Influence of Apical Preparation Size and Working Length on Debris Extrusion.

The aim of this study was to quantitatively evaluate the amount of apically extruded debris by single-file reciprocating instruments with different working lengths and apical preparation sizes. Eighty human single-rooted mandibular incisors were used and conventional access cavities were prepared. Then, the specimens were divided into four groups (n=20), according to root canal instrumentation: Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used at the foramen; Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used 1 mm short of the foramen. Distilled water was used as an irrigant and the apically extruded debris were collected in pre-weighted glass vials and dried afterwards. The mean weight of debris was weighed with a microbalance and statistically analyzed using one-way analysis of variance and the post hoc Tukey multiple comparison test (p<0.05). The results showed that all experimental groups were associated with debris extrusion. No significant difference was found in the amount of apically extruded debris among all experimental groups (p>0.05). The present study demonstrated that the working length and the apical preparation size did not have a significant effect on debris extrusion when performing single-file reciprocating instrumentation.

Influence of Apical Preparation Size and Working Length on Debris Extrusion

Abstract The aim of this study was to quantitatively evaluate the amount of apically extruded debris by single-file reciprocating instruments with different working lengths and apical preparation sizes. Eighty human single-rooted mandibular incisors were used and conventional access cavities were prepared. Then, the specimens were divided into four groups (n=20), according to root canal instrumentation: Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used at the foramen; Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used 1 mm short of the foramen. Distilled water was used as an irrigant and the apically extruded debris were collected in pre-weighted glass vials and dried afterwards. The mean weight of debris was weighed with a microbalance and statistically analyzed using one-way analysis of variance and the post hoc Tukey multiple comparison test (p<0.05). The results showed that all experimental groups were associated with debris extrusion. No significant difference was found in the amount of apically extruded debris among all experimental groups (p>0.05). The present study demonstrated that the working length and the apical preparation size did not have a significant effect on debris extrusion when performing single-file reciprocating instrumentation.

Resumo Este estudo avaliou quantitativamente a quantidade de material extruído apicalmente pela instrumentação com lima única reciprocante, aplicando diferentes comprimentos de trabalho e tamanhos de preparo apical. Para a análise de extrusão foram utilizados oitenta incisivos inferiores unirradiculares humanos. Cavidades de acesso convencionais foram preparadas e os espécimes foram divididos em quatro grupos (n=20), de acordo com o tipo de instrumentação do canal: Reciproc 25, 0.08 e Reciproc 40, 0.06 foram utilizadas na instrumentação até o forame; Reciproc tamanho 25, 0.08 e Reciproc 40, 0,06 foram utilizadas na instrumentação até 1 mm aquém do forame. Água destilada foi empregada como irrigante e o material extruído apicalmente foi coletado em frascos de vidro já pesados e posteriormente submetidos a secagem. O peso médio de detritos foi avaliado com uma microbalança de precisão e os dados submetidos a ANOVA e teste Tukey (p<0,05). Todos os grupos experimentais foram associados à extrusão de debris. Nenhuma diferença significativa foi encontrada na quantidade de material extruído apicalmente entre os grupos (p>0,05). Este estudo demonstrou que o comprimento de trabalho e o tamanho do preparo apical não geraram efeito significativo sobre a extrusão de debris durante a instrumentação reciprocante.

Endodontic treatment of a mandibular hypertaurodontic second molar / Tratamento endodôntico de segundo molar inferior com hipertaurodontia

Taurodontism is the consequence of a developmental disorder in which the invagination of Hertwig's epithelial root sheath doesn't occur at a proper level. As a result, the pulp body and the chamber of a multi-root tooth, usually permanent molar teeth, are enlarged by the apical displacement of the pulp floor. Despite its clinically normal appearance, the morphological variation of this tooth can be diagnosed by a routine radiographic exam that shows enlarged apico-occlusal pulp chamber and short roots. Due to these anatomical variations, endodontic treatment of a taurodontic element is a clinical challenge given the complexity of localization and instrumentation of the root canal system. According to the degree of displacement of the pulp floor, taurodontism can be classified as: hypotaurodontism, mesotaurodontism and hypertaurodontism. This study objective is to report a clinical case of a patient who was submitted to endodontic treatment of the second inferior molar affected by hypertaurodontism.

A taurodontia é consequência de um distúrbio de desenvolvimento em que a bainha epitelial de Hertwig não invagina corretamente em um nível normal, repercutindo em um aumento do corpo e da câmara pulpar de um dente multiradicular, predominantemente molares permanentes, pelo deslocamento do assoalho pulpar no sentido apical. Apesar de clinicamente aparentar-se como um dente normal, esta variação morfológica pode ser diagnosticada por exame radiográfico de rotina evidenciando câmara pulpar aumentadas em tamanho no sentido ápico-oclusal e raízes curtas. Devido a estas alterações anatômicas, o tratamento endodôntico de um elemento com taurodontia se torna um desafio clínico, já que é necessário um cuidado especial na localização e manejo do sistema de canais radiculares. De acordo com o grau de deslocamento apical do assoalho pulpar, a taurodontia pode ser classificada em: hipotaurodontia, mesotaurodontia e hipertaurodontia. O objetivo deste trabalho é relatar o caso clínico de um paciente que necessitou de tratamento endodôntico em um segundo molar inferior com hipertaurodontia.

Effectiveness of rotatory and reciprocating movements in root canal filling material removal.

The purpose of this study was to compare the efficacy of reciprocating and rotary techniques for removing gutta-percha and sealer from root canals. Forty straight and oval single-rooted premolars were prepared up to size 30, filled with gutta-percha and sealer, and then randomly allocated to two experimental retreatment groups: ProTaper Retreatment System (PTRS) and WaveOne System (WS). Procedural errors, time of retreatment and apically extruded material were recorded for all the roots. The roots were radiographed after retreatment. The percentage of residual material was calculated using image analysis software. The data were analyzed by Kolmogorov-Smirnov and t tests, with a significance level set at 5%. No system completely removed the root filling material from the root canal. No significant differences were observed between the systems, in terms of residual filling material in any tested third (p > 0.05). WS was faster in removing filling material than PTRS (p < 0.05). Extrusion was observed in 4 cases in PTRS and in 5 cases in WS. No procedural errors were observed in either group. It can be concluded that although no differences were observed in the efficacy of PTRS and WS for removing root filling material, WS was faster than PTRS.

Effectiveness of rotatory and reciprocating movements in root canal filling material removal

The purpose of this study was to compare the efficacy of reciprocating and rotary techniques for removing gutta-percha and sealer from root canals. Forty straight and oval single-rooted premolars were prepared up to size 30, filled with gutta-percha and sealer, and then randomly allocated to two experimental retreatment groups: ProTaper Retreatment System (PTRS) and WaveOne System (WS). Procedural errors, time of retreatment and apically extruded material were recorded for all the roots. The roots were radiographed after retreatment. The percentage of residual material was calculated using image analysis software. The data were analyzed by Kolmogorov-Smirnov and t tests, with a significance level set at 5%. No system completely removed the root filling material from the root canal. No significant differences were observed between the systems, in terms of residual filling material in any tested third (p > 0.05). WS was faster in removing filling material than PTRS (p< 0.05). Extrusion was observed in 4 cases in PTRS and in 5 cases in WS. No procedural errors were observed in either group. It can be concluded that although no differences were observed in the efficacy of PTRS and WS for removing root filling material, WS was faster than PTRS.

Evaluation of photodynamic therapy using a diode laser and different photosensitizers against enterococcus faecalis.

Photodynamic therapy (PDT) has been proven to be effective in disinfecting root canals. The aim of this present study was to evaluate the effects of PDT on the viability of Enterococcus faecalis using methylene blue (MB) and malachite green (MG) as photosensitizers. Solutions containing E. faecalis (ATCC 29212) were prepared and harvested by centrifugation to obtain cell suspensions, which were mixed with MB and MG. Samples were individually irradiated by the diode laser at a distance of 1mm for 30, 60, or 120 seconds. Colonyforming units (CFU) were determined for each treatment. PDT for 60 and 120 seconds with MG reduced E. faecalis viability significantly. Similar results were obtained when MB was used as photosensitizer. PDT using MB and MG have antibacterial effect against E. faecalis, showing potential to be used as an adjunctive antimicrobial procedure in endodontic therapy.

Push-out bond strength of a self-adhesive resin cement used as endodontic sealer.

OBJECTIVES: The aim of the present study was to investigate the bond strength of RelyX Unicem (3M) to root canal dentin when used as an endodontic sealer. MATERIALS AND METHODS: Samples of 24 single-rooted teeth were prepared with Gates Glidden drills and K3 files. After that, the roots were randomly assigned to three experimental groups (n = 8) according to the filling material, (1) AH Plus (Dentsply De Trey GmbH)/Gutta-Percha cone; (2) Epiphany SE (Pentron)/Resilon cone; (3) RelyX Unicem/Gutta-Percha cone. All roots were filled using a single cone technique associated to vertical condensation. After the filling procedures, each tooth was prepared for a push-out bond strenght test by cutting 1 mm-thick root slices. Loading was performed on a universal testing machine at a speed of 0.5 mm/min. One-way analysis of variance and Tukey test for multiple comparisons were used to compare the results among the experimental groups. RESULTS: Epiphany SE/Resilon showed significantly lower push-out bond strength than both AH Plus/Gutta-Percha and RelyX Unicem/Gutta-Percha (p < 0.05). There was no significant difference in bond strength between AH Plus/Gutta-Percha and RelyX Unicem/Gutta-Percha (p > 0.05). CONCLUSIONS: Under the present in vitro conditions, bond strength to root dentin promoted by RelyX Unicem was similar to AH Plus. Epiphany SE/Resilon resulted in lower bond strength values when compared to both materials.

Evaluation of photodynamic therapy using a diode laser and different photosensitizers against Enterococcus faecalis

Photodynamic therapy (PDT) has been proven to be effectivein disinfecting root canals. The aim of this present study wasto evaluate the effects of PDT on the viability of Enterococcusfaecalis using methylene blue (MB) and malachite green(MG) as photosensitizers. Solutions containing E. faecalis(ATCC 29212) were prepared and harvested by centrifugationto obtain cell suspensions, which were mixed with MBand MG. Samples were individually irradiated by the diodelaser at a distance of 1mm for 30, 60, or 120 seconds. Colonyformingunits (CFU) were determined for each treatment.PDT for 60 and 120 seconds with MG reduced E. faecalis viabilitysignificantly. Similar results were obtained when MBwas used as photosensitizer. PDT using MB and MG haveantibacterial effect against E. faecalis, showing potential tobe used as an adjunctive antimicrobial procedure in endodontictherapy...

Evaluation of photodynamic therapy using a diode laser and different photosensitizers against enterococcus faecalis. / Evaluation of photodynamic therapy using a diode laser and different photosensitizers against enterococcus faecalis.

Photodynamic therapy (PDT) has been proven to be effective in disinfecting root canals. The aim of this present study was to evaluate the effects of PDT on the viability of Enterococcus faecalis using methylene blue (MB) and malachite green (MG) as photosensitizers. Solutions containing E. faecalis (ATCC 29212) were prepared and harvested by centrifugation to obtain cell suspensions, which were mixed with MB and MG. Samples were individually irradiated by the diode laser at a distance of 1mm for 30, 60, or 120 seconds. Colonyforming units (CFU) were determined for each treatment. PDT for 60 and 120 seconds with MG reduced E. faecalis viability significantly. Similar results were obtained when MB was used as photosensitizer. PDT using MB and MG have antibacterial effect against E. faecalis, showing potential to be used as an adjunctive antimicrobial procedure in endodontic therapy.

A multiparametric assay to compare the cytotoxicity of different storage media for avulsed teeth

Aim: To evaluate the cytotoxicity of several storage media (coconut water, whole milk, isotonicsolution, Hank´s Balanced Salt Solution and tap water) using a multiparametric cytotoxicity analysisemploying 3T3 cells. Methods: Plates containing confluent 3T3 fibroblasts were exposed to thevarious media for 24h, at 37°C with 5% CO2, and cell viability was evaluated by a multiparametricassay assessing sequentially, on the same cells, mitochondrial activity (XTT), membrane integrity(neutral red test), and total cell density (crystal violet dye exclusion test). Results from each testwere compared by one-way analysis of variance (ANOVA). Results: Statistical analysis showedthat whole milk and HBSS were the most effective media in maintaining cell viability at all testedtimes (p<0.05). Isotonic and tap water showed the highest cytotoxicity effects. Conclusions: Thisstudy shows that whole milk and HBSS are more efficient in maintaining the viability of 3T3fibroblasts as demonstrated by three different cell viability tests.

Postoperative pain after foraminal enlargement in anterior teeth with necrosis and apical periodontitis: a prospective and randomized clinical trial.

INTRODUCTION: The aim of this randomized, controlled, prospective clinical study was to determine if foraminal enlargement instrumentation during endodontic treatment is associated with more postoperative pain compared with standard nonenlargement instrumentation. METHODS: Forty volunteers with a single root canal were diagnosed with asymptomatic necrosis with apical periodontitis and randomized into 2 experimental groups (ie, the control group and the foraminal enlargement group). Endodontic treatment was performed in a single visit, and volunteers were instructed to record pain intensity (ie, none, slight, moderate, and severe). Scores from 1 to 4 were attributed to each kind of pain after 12, 24, and 48 hours. The Kolmogorov-Smirnov and Student's t tests were used to determine significant differences at P < .05. RESULTS: No statistically significant age difference was found between the groups (P > .05, Student's t test). Postoperative pain showed no statistically significant difference between the groups at any observation period (P > .05). Also, no significant difference was observed in the mean number of analgesic tablets used between the groups (P > .05). CONCLUSIONS: The foraminal enlargement and nonenlargement techniques resulted in the same postoperative pain and necessity for analgesic medication. This may suggest that the use of foraminal enlargement should be performed for endodontic treatment previsibility without increasing postoperative pain.

A multiparametric assay to compare the cytotoxicity of soy milk with different storage media.

BACKGROUND/AIM: The aim of this study was to evaluate the cytotoxicity of soy milk compared with several other storage media [coconut water, Hank's Balanced Salt Solution (HBSS) and whole milk], assessed through a multiparametric analysis employing 3T3 cells. MATERIALS AND METHODS: Plates containing confluent 3T3 fibroblasts were exposed to the various media for 24 h, at 37°C with 5% CO2, and cell viability was evaluated by a multiparametric assay assessing sequentially, on the same cells, mitochondrial activity (XTT), membrane integrity (neutral red test) and total cell density (crystal violet dye exclusion test). Results from each test were compared by two-way analysis of variance (ANOVA). RESULTS: Statistical analysis showed that whole milk, HBSS and soy milk were the most effective media in maintaining cell viability at all tested times (P < 0.05). The least amount of viable cells was observed when using coconut water. CONCLUSIONS: This study shows that the efficacy of soy milk in maintaining the viability of 3T3 fibroblasts is similar to that of HBSS and milk, as shown by three different cell viability tests.

Use of soymilk as a storage medium for avulsed teeth.

OBJECTIVE: Tooth avulsion is one of the most severe forms of dental trauma. In these cases, immediate reimplantation is ideal; however, it almost never happens. The purpose of this study was to evaluate the viability of cells stored in soymilk and compare with other several storage media. MATERIALS AND METHODS: The media tested were: long-shelf-life coconut water, long-shelf-life whole milk, long-shelf-life soymilk, Gatorade, egg white, and Hank's Balanced Salt Solution. Cells cultured in DMEM and distilled water served as positive and negative controls, respectively. Plates containing confluent 3T3 fibroblast were soaked in the various media for 2, 12 and 24 h. After incubation at 37°C, viability of the cells was determined using the MTS assay. Data were analyzed by using one-way ANOVA and complemented by Tukey test with a significance level of 5%. RESULTS: Statistical analysis showed that DMEM, whole milk, HBSS and soymilk were the most effective media for maintaining cell viability at all tested times (p < 0.05), followed by coconut water, egg white and Gatorade. The least amount of viable cells was observed in the distilled water group. CONCLUSIONS: The present study shows that the efficacy of soymilk in maintaining the viability of 3T3 fibroblasts is similar to that of HBSS and milk. Therefore, it can be concluded that soymilk could be a suitable alternative storage medium for avulsed teeth.

Avaliação antimicrobiana dos vapores de para monoclorofenol e tricresol formalina utilizando uma nova metodologia / Antimicrobial evaluation of vapors of paramonochlorophenol and tricresol formalin using a new methodology

O objetivo do presente estudo foi avaliar o efeito antimicrobiano do Paramonoclorofenol Canforado (PMCFC) e do Tricresol Formalina (TF) frente ao Enterococcus faecalis utilizando uma nova metodologia para simular a volatilização dos compostos. Enterococcus faecalis foram inoculados em placas de Petri com BHI, na qual foram fincados escalpes contendo algodão embebido em PMCFC e TF. Bolinhas de algodão sem medicação foram utilizadas como controle negativo. Após 48 horas de cultivo, foi avaliada a formação de halos de inibição de crescimento bacteriano. Pode-se constatar que o grupo com TF produziu halos de inibição em 100% dos escalpes, enquanto o PMCFC e o controle negativo não produziram halo de inibição. Conclui-se que somente o TF apresentou atividade antimicrobiana por volatilização.

The aim of the present study was to evaluate the antimicrobial effects of paramonochlorophenol and tricresol formalin using a new methodology to simulate the volatilization of these substances. Enterococcus faecalis were inoculated em petri dishes with BHI and mm scalps containing cotton balls soaked with the tested substances were stucked in the petri dishes. Cotton balls without medication were used as negative control. After 48 hours the inhibition halo formation was evaluated. The results showed that tricresol formalin group presented inhinition zones in 100% of scalps, while paramochlorophenol and control group produced no inhibition zone. The results suggested that the vapor of formalin tricresol has antibacterial activity; however paramonochlorophenol was unable to exert antibacterial activity from the volatilization of its gases.

Surgical Alternative for Treatment of Vertical Root fracture: A Case Report.

Vertical root fracture (VRF) has been a great challenge in dentistry; most fractures often result in tooth extraction. Inflammation of tissues around the fractured root is the main reason for tooth extraction. Based on the strategic importance of some fractured teeth, treatment may be necessary and often complicated. However, performing a proper repair or even splinting the fractured segments may result in tooth preservation. Accordingly, in this case we report a new method for fractured tooth preservation. The surgical exposition of the fracture tooth was carried out through the radicular portion of the element via ultrasonic preparation, filling with composed resin and a synthetic hydroxyapatite graft. All these were performed around the tooth which received five sections of low-power laser. The patient was followed for two years with no signs or symptoms of inflammation and gingival recession. In conclusion, the used treatment protocol could be considered as a promising approach for VRF treatment, especially in cases where there is advanced or moderate bone loss in the surrounding sites of the fractured tooth.

Preliminary investigation to achieve patency of MB2 canal in maxillary molars

Aim: To establish a preliminary investigation about the possibility to achieve patency of second mesiobuccal canal (MB2) in mesiobuccal roots of maxillary molars. Methods: Three hundred and five first maxillary molars were examined with direct vision and with magnification. The root canal configurations were classified according to the possibility to achieve patency in MB2 canals. Clearing technique was also performed to illustrate root canal anatomy and verify the presence of extra canals not identified with magnification. Results: The prevalence of MB2 canals detected only with direct vision was 53.4% and the use of the surgical operating microscope increased rate detection to 90.7%. The clearing technique revealed the presence of MB2 canal in 12 more teeth (94.7%). In 49.1% of the localized MB2 canals, it was not possible to achieve patency. Conclusions: The findings of the presented study revealed that it was only possible to achieve patency in 50.9% of the MB2 canals, showing that achieve patency in the MB2 canal is much more challenging than locating them.

Clinical reproducibility of a low cost electronic apex locator

Aim: To evaluate the clinical reproducibility of three electronic apex locators (EALs), Joypex 5,RomiApex A-15 and Novapex. Methods: Twenty-five patients requiring endodontic treatmentwere selected. Sixty root canals were measured by the three EALs to determine their respectiveworking length, which was defined as a zero reading on the EAL. A new K-file of the same sizewas used for each measurement. The file length was fixed with a rubber stop and measured witha caliper to an accuracy of 0.1 mm. Data were analyzed statistically using paired t-tests with theBonferroni correction and Bland-Altman plot to determine the reproducibility of clinical dataamong the EALs. Significance level was set at 5%. Results: Mean and standard deviationvalues measured by the three EALs showed no statistically significant differences. Identicalreadings by all three EALs were found in 38% of root canals. Fifty percent differed by less than± 1.0 mm and only 1.3% exceeded a difference of 2.0 mm. Conclusions: The clinicalreproducibility of the three devices was confirmed with no significant differences among them,indicating that they are effective for clinical use.

Behavior of subcutaneous tissue of rats in response to infected dentine associated with different endodontic irrigants / Comportamento do tecido subcutâneo de ratos frente à dentina infectada e associada a diferentes irrigantes endodônticos

PURPOSE: To compare rat subcutaneous connective tissue reaction to dentine contaminated with Enterococcus faecalis associated with 0.9% sterile saline, 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine gel (CHX). METHODS: Dentine was crushed into powder and inoculated with E. faecalis. Tested substances were mixed with contaminated dentine and placed in polyethylene tubes. Ten male Wistar rats had their backs divided into four quadrants that received an implant containing one of the tested substances. An empty tube was used as a control. Five rats were randomly distributed for evaluation at time intervals of 24 hours and 72 hours. Tissue samples were histologically processed. Tissue reactions to experimental groups were evaluated under optical microscopes. RESULTS: Groups of 5.25% NaOCl induced greater inflammatory response after 24 hours and 72 hours. Compared to groups of 2% CHX, the groups of 0.9% sterile saline showed milder inflammatory reactions after 24 hours and more severe after 72 hours. CONCLUSION: The results indicate that 5.25% NaOCl group showed a higher inflammatory reaction to rat subcutaneous connective tissue and the 2% chlorhexidine group showed the least reaction.

OBJETIVO: Comparar a resposta do tecido subcutâneo de ratos frente a dentina contaminada com Enterococcus faecalis associado ao soro fisiológico 0.9% , hipoclorito de sódio 5.25% (NaOCl) ou clorexidina gel 2% (CHX). METODOLOGIA: Foi realizada a contaminação de dentina em pó com E. faecalis. As substâncias testadas foram misturadas com a dentina contaminada e inseridas em tubos de polietileno. Dez ratos Wistar tiveram os dorsos divididos em quatro quadrantes e cada quadrante recebeu um tubo com cada uma das misturas testadas. Um tubo vazio foi utilizado como controle. Os ratos foram distribuídos em dois grupos para avaliação no período de 24 e 72 horas. Os tecidos foram processados histologicamente e as reações teciduais foram avaliadas sobre microscopia de luz. RESULTADOS: Os grupos de NaOCl 5.25% promoveram maiores reações inflamatória após 24 e 72 horas. Quando comparado com os grupos de CHX 2%, os grupos de soro fisiológico 0.9% mostraram inflamação moderada após 24 horas e severa após 72 horas. CONCLUSÃO: Os resultados indicaram que o grupo de NaOCl 5.25% apresentou maior reação inflamatória aos tecidos subcutâneos de rato e que o grupo de CHX 2% apresentou menor reação inflamatória.