RESUMO
ABSTRACT Objective This study compared the effectiveness of Er:YAG laser-activated irrigation (PIPS), passive ultrasonic irrigation (PUI) with EndoUltra and standard needle irrigation (SNI) in the removal of calcium hydroxide [Ca(OH)2] from the mesial roots of Weine Type II mandibular molars. Material and Methods Thirty mandibular molars were screened by µCT for the presence of mesial roots with complex intra-canal anatomy and a common apical foramen. The teeth were enlarged to a standardized 25/.06 preparation and filled with Ca(OH)2 paste. Specimens were divided into three groups (n=10) according to the technique used for Ca(OH)2 removal: PIPS, at 15 Hz and 20 mJ using a 9 mm long, 600 µm diameter tip; PUI using a 15/.02 tip; and SNI (30 Ga. side-vented needle). Equal volumes of 8.25% NaOCl and 17% EDTA were used in all groups. µCT was used to measure the initial amount of Ca(OH)2 present and to assess the residual volume of Ca(OH)2 following each irrigation protocol. Data were analyzed using Tukey HSD and Kruskal-Wallis tests (α=5%). Results The mean volume of Ca(OH)2 before removal was significantly higher in the coronal third than in the middle and apical third (p<0.001). Ca(OH)2 was similarly removed from the coronal and middle thirds with the three methods used (p>0.05). PIPS (median 0%; IQR: 0-0) showed significant higher Ca(OH)2 removal in the apical third than PUI (median 100%, IQR: 85-100) and SNI (median 47%; IQR: 16-72) (p<0.001). Conclusions PIPS laser-activation was more effective for the removal of Ca(OH)2 from mesial roots of mandibular molars with Weine Type II canal configurations than PUI with EndoUltra and SNI.
Assuntos
Humanos , Irrigantes do Canal Radicular/química , Hidróxido de Cálcio/química , Preparo de Canal Radicular/instrumentação , Terapia por Ultrassom/métodos , Reprodutibilidade dos Testes , Análise de Variância , Estatísticas não Paramétricas , Preparo de Canal Radicular/métodos , Cavidade Pulpar/efeitos dos fármacos , Lasers de Estado Sólido/uso terapêutico , Microtomografia por Raio-X/métodos , Técnicas Fotoacústicas/métodos , Irrigação Terapêutica/métodos , Dente Molar , AgulhasRESUMO
OBJECTIVE: This study compared the effectiveness of Er:YAG laser-activated irrigation (PIPS), passive ultrasonic irrigation (PUI) with EndoUltra and standard needle irrigation (SNI) in the removal of calcium hydroxide [Ca(OH)2] from the mesial roots of Weine Type II mandibular molars. MATERIAL AND METHODS: Thirty mandibular molars were screened by µCT for the presence of mesial roots with complex intra-canal anatomy and a common apical foramen. The teeth were enlarged to a standardized 25/.06 preparation and filled with Ca(OH)2 paste. Specimens were divided into three groups (n=10) according to the technique used for Ca(OH)2 removal: PIPS, at 15 Hz and 20 mJ using a 9 mm long, 600 µm diameter tip; PUI using a 15/.02 tip; and SNI (30 Ga. side-vented needle). Equal volumes of 8.25% NaOCl and 17% EDTA were used in all groups. µCT was used to measure the initial amount of Ca(OH)2 present and to assess the residual volume of Ca(OH)2 following each irrigation protocol. Data were analyzed using Tukey HSD and Kruskal-Wallis tests (α=5%). RESULTS: The mean volume of Ca(OH)2 before removal was significantly higher in the coronal third than in the middle and apical third (p<0.001). Ca(OH)2 was similarly removed from the coronal and middle thirds with the three methods used (p>0.05). PIPS (median 0%; IQR: 0-0) showed significant higher Ca(OH)2 removal in the apical third than PUI (median 100%, IQR: 85-100) and SNI (median 47%; IQR: 16-72) (p<0.001). CONCLUSIONS: PIPS laser-activation was more effective for the removal of Ca(OH)2 from mesial roots of mandibular molars with Weine Type II canal configurations than PUI with EndoUltra and SNI.
Assuntos
Hidróxido de Cálcio/química , Irrigantes do Canal Radicular/química , Preparo de Canal Radicular/instrumentação , Análise de Variância , Cavidade Pulpar/efeitos dos fármacos , Humanos , Lasers de Estado Sólido/uso terapêutico , Dente Molar , Agulhas , Técnicas Fotoacústicas/métodos , Reprodutibilidade dos Testes , Preparo de Canal Radicular/métodos , Estatísticas não Paramétricas , Irrigação Terapêutica/métodos , Terapia por Ultrassom/métodos , Microtomografia por Raio-X/métodosRESUMO
The cleaning capacity of Hero 642 nickel-titanium files, complemented by the Hero Apical instruments in flattened roots, was determined by histological analysis, considering the area of action of the instruments on the coronal walls and the presence of remaining debris. Twenty-four single-canal, human mandibular incisors were divided into three groups and prepared as follows: GI, instrumented with Hero 642 NiTi files 30/.06, 25/.06, 20/.06, 25/.06, and 30/.06; GII, instrumented as GI followed by Hero Apical size 30/.06; GIII, instrumented as GI followed by Hero Apical sizes 30/.06 and 30/.08, then returning to 30/.06 with pendulum movements. The apical thirds were prepared for histological processing, analyzed at 40× magnification and the images were examined morphometrically. Statistical analysis showed that GIII presented the best results for removing debris (5.22% ± 4.13), with more contact between the instruments and the root canal walls (19.31% ± 0.15). This differed statistically from GI (14.04% ± 4.96 debris removal, with 42.96% ± 7.11 instrument contact) and GII (12.62% ± 5.76 debris removal, with 35.01% ± 0.15 instrument contact). Root canal preparation with Hero 642, complemented by Hero Apical instruments (30/.06 and 30/.08, then re-instrumented with Hero Apical 30/.06 using pendulum movements), was more efficient for debris removal and allowed more contact of the instruments with the root canal walls. GII presented the worst results.
Assuntos
Cavidade Pulpar/anatomia & histologia , Preparo de Canal Radicular/instrumentação , Análise de Variância , Desenho de Equipamento , Humanos , Incisivo , Níquel , TitânioRESUMO
The cleaning capacity of Hero 642 nickel-titanium files, complemented by the Hero Apical instruments in flattened roots, was determined by histological analysis, considering the area of action of the instruments on the coronal walls and the presence of remaining debris. Twenty-four single-canal, human mandibular incisors were divided into three groups and prepared as follows: GI, instrumented with Hero 642 NiTi files 30/.06, 25/.06, 20/.06, 25/.06, and 30/.06; GII, instrumented as GI followed by Hero Apical size 30/.06; GIII, instrumented as GI followed by Hero Apical sizes 30/.06 and 30/.08, then returning to 30/.06 with pendulum movements. The apical thirds were prepared for histological processing, analyzed at 40× magnification and the images were examined morphometrically. Statistical analysis showed that GIII presented the best results for removing debris (5.22 percent ± 4.13), with more contact between the instruments and the root canal walls (19.31 percent ± 0.15). This differed statistically from GI (14.04 percent ± 4.96 debris removal, with 42.96 percent ± 7.11 instrument contact) and GII (12.62 percent ± 5.76 debris removal, with 35.01 percent ± 0.15 instrument contact). Root canal preparation with Hero 642, complemented by Hero Apical instruments (30/.06 and 30/.08, then re-instrumented with Hero Apical 30/.06 using pendulum movements), was more efficient for debris removal and allowed more contact of the instruments with the root canal walls. GII presented the worst results.
Assuntos
Humanos , Cavidade Pulpar/anatomia & histologia , Preparo de Canal Radicular/instrumentação , Análise de Variância , Desenho de Equipamento , Incisivo , Níquel , TitânioRESUMO
OBJECTIVE: This study evaluated ultra-structural dentine changes at the apical stop after CO(2) laser irradiation used during biomechanical preparation. BACKGROUND: Most studies evaluating the sealing efficiency of CO(2) lasers have been carried out after apical root canal resections and retro-filling procedures. METHODS: Sixty human canines were prepared with #1 to #6 Largo burs. The apical stops were established at 1 mm (n = 30) and 2 mm (n = 30) from the apex. Final irrigation was performed with 1% NaOCl and 15% EDTA followed by 20 ml of distilled and deionized water. Specimens were subdivided into three subgroups (n = 10 for each stop distance): GI- no radiation (n = 20); GII- 3W potency (n = 20), GIII- 5W potency (n = 20). After preparation, specimens were evaluated by scanning electron microscopy, with ultra-structural changes classified according to a scoring system based on six qualitatively different outcomes. RESULTS: Statistical analysis using the Mann-Whitney test confirmed more intense results for the specimens irradiated at 5 W potency than at 3 W (p < 0.0001). The Kruskal-Wallis test indicated that when using the same potencies (3 or 5 W) at 1 and 2 mm from the apex, there were no statistically significant differences in ultra-structural changes. CONCLUSIONS: Our results showed that ultra-structural changes ranged from smear layer removal to dentine fusion. As laser potency was increased from 3 to 5 W, ultra-structural changes included extensive fused lava-like areas sealing the apical foramen.
Assuntos
Dentina/efeitos da radiação , Dentina/ultraestrutura , Lasers , Preparo de Canal Radicular/métodos , Dióxido de Carbono , Relação Dose-Resposta à Radiação , Humanos , Microscopia Eletrônica de Varredura , Irrigantes do Canal Radicular/farmacologia , Camada de Esfregaço , Raiz Dentária/efeitos da radiaçãoRESUMO
This ex vivo study evaluated dentin permeability of the root canal in the apical third of different human groups of teeth. Eighty teeth were used, 8 from each dental group: maxillary and mandibular central incisors, lateral incisors and canines, maxillary first premolars (buccal and palatal roots), mandibular first premolars, and maxillary and mandibular second premolars, totalizing 88 roots that were distributed in 11 groups. The root canals were instrumented, irrigated with 1% NaOCl and 15% EDTA. Roots were immersed in 10% copper sulfate for 30 min and then in 1% rubeanic acid alcohol solution for the same period; this chemical reaction reveals dentin permeability by the formation of copper rubeanate, which is a dark-colored compound. Semi-serial 100-µm-thick cross-sections were obtained from the apical third of the roots. Five sections of each apical third were washed, dehydrated, cleared and mounted on glass slides for examination under optical microscopy. The percentage of copper ion infiltration and the amount of tubular dentin were quantified by morphometric analysis. The penetration of copper ions in the apical third ranged from 4.60 to 16.66%. The mandibular central and lateral incisors presented the highest dentin permeability (16.66%), while the maxillary canines and mandibular second and first premolars presented the lowest dentin permeability (4.60%, 4.80% and 5.71%, respectively; p<0.001). The other teeth presented intermediate permeability. In conclusion, dye penetration into dentin tubules at the apical region is strongly dependent on the group of teeth evaluated.
Assuntos
Corantes/farmacocinética , Cavidade Pulpar/metabolismo , Permeabilidade da Dentina , Tioamidas/farmacocinética , Ápice Dentário , Cobre/farmacocinética , Humanos , Mandíbula , Maxila , Dente/anatomia & histologia , Dente/metabolismoRESUMO
This ex vivo study evaluated dentin permeability of the root canal in the apical third of different human groups of teeth. Eighty teeth were used, 8 from each dental group: maxillary and mandibular central incisors, lateral incisors and canines, maxillary first premolars (buccal and palatal roots), mandibular first premolars, and maxillary and mandibular second premolars, totalizing 88 roots that were distributed in 11 groups. The root canals were instrumented, irrigated with 1 percent NaOCl and 15 percent EDTA. Roots were immersed in 10 percent copper sulfate for 30 min and then in 1 percent rubeanic acid alcohol solution for the same period; this chemical reaction reveals dentin permeability by the formation of copper rubeanate, which is a dark-colored compound. Semi-serial 100-µm-thick cross-sections were obtained from the apical third of the roots. Five sections of each apical third were washed, dehydrated, cleared and mounted on glass slides for examination under optical microscopy. The percentage of copper ion infiltration and the amount of tubular dentin were quantified by morphometric analysis. The penetration of copper ions in the apical third ranged from 4.60 to 16.66 percent. The mandibular central and lateral incisors presented the highest dentin permeability (16.66 percent), while the maxillary canines and mandibular second and first premolars presented the lowest dentin permeability (4.60 percent, 4.80 percent and 5.71 percent, respectively; p<0.001). The other teeth presented intermediate permeability. In conclusion, dye penetration into dentin tubules at the apical region is strongly dependent on the group of teeth evaluated.
Este estudo ex vivo avaliou a permeabilidade da dentina do canal radicular do terço apical de diferentes grupos de dentes humanos. Foram utilizados 80 dentes, sendo 8 de cada grupo dental superior e inferior: incisivos centrais, incisivos laterais, caninos, primeiros pré-molares superiores (raízes vestibulares e palatinas), primeiros pré-molares inferiores, segundos pré-molares superiores e inferiores, totalizando 88 raízes, as quais foram distribuídas em 11 grupos. Os canais foram instrumentados, irrigados com NaOCl a 1 por cento e EDTA a 15 por cento. As raízes foram imersas em sulfato de cobre a 10 por cento por 30 min e acido rubeânico a 1 por cento pelo mesmo período. Esta reação química revela a permeabilidade da dentina por meio da formação de um complexo escurecido denominado rubeanato de cobre. Hemi-secções de 100 µm de espessura foram obtidas do terço apical da raiz. Cinco secções do terço apical foram lavadas, desidratadas, diafanizadas e montadas em lâminas para análise em microscopia óptica. A porcentagem de infiltração de íons cobre e a quantidade de dentina tubular foram quantificadas por meio de análise morfométrica. A penetração de íons cobre no terço apical da raiz variou de 4,60 por cento a 16,66 por cento. Os incisivos centrais e laterais apresentaram a maior permeabilidade dentinária (16,66 por cento), e os caninos superiores e segundos e primeiros pré-molares inferiores as menores (4,60 por cento, 4,80 por cento e 5,71 por cento, respectivamente; p<0,001). Os outros dentes apresentaram permeabilidade intermediaria. Conclui-se que a penetração de corante nos túbulos dentinários da região apical é extremamente dependente do grupo de dentes avaliado.
Assuntos
Humanos , Corantes/farmacocinética , Permeabilidade da Dentina , Cavidade Pulpar/metabolismo , Ápice Dentário , Tioamidas/farmacocinética , Cobre/farmacocinética , Mandíbula , Maxila , Dente/anatomia & histologia , Dente/metabolismoRESUMO
This study evaluated the influence of internal tooth bleaching with 38% hydrogen peroxide (H2O2) on the permeability of the coronal dentin in maxillary anterior teeth and premolars. Seventy teeth (14 per group) were used: central incisors (CI), lateral incisor (LI), canines (C), first premolars (1PM) and second premolars (2PM). Pulp chamber access and transversal sectioning at 2 mm from the cementoenamel junction were performed and the specimens were divided into 2 groups (n= 7): a) no treatment and b) bleaching with 38% H2O2. The bleaching agent was applied to the buccal surface and to the pulp chamber for 10 min. This procedure was repeated 3 times. The specimens were processed histochemically with copper sulfate and rubeanic acid, sectioned longitudinally, and digitalized in a scanner. The area of stained dentin was measured using Image Tool software. Data were analyzed statistically by ANOVA and Tukey's HSD test (alpha=0.05). There was statistically significant difference (p<0.001) among the untreated groups, CI (0.23 +/- 0.26) having the lowest permeability and LI (10.14 +/- 1.89) the highest permeability. Among the bleached groups, dentin permeability was increased in all groups of teeth except for 2PM. It may be concluded that bleaching with 38% H2O2 affected dentin permeability near the pulp chamber in maxillary anterior teeth and in first and second premolars.
Assuntos
Cavidade Pulpar/efeitos dos fármacos , Permeabilidade da Dentina/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Irrigantes do Canal Radicular/farmacologia , Clareamento Dental/métodos , Corantes/farmacologia , Cobre/farmacologia , Permeabilidade do Esmalte Dentário/efeitos dos fármacos , Humanos , Maxila , Oxidantes/farmacologia , Dente não VitalRESUMO
This study evaluated the influence of internal tooth bleaching with 38 percent hydrogen peroxide (H2O2) on the permeability of the coronal dentin in maxillary anterior teeth and premolars. Seventy teeth (14 per group) were used: central incisors (CI), lateral incisor (LI), canines (C), first premolars (1PM) and second premolars (2PM). Pulp chamber access and transversal sectioning at 2 mm from the cementoenamel junction were performed and the specimens were divided into 2 groups (n= 7): a) no treatment and b) bleaching with 38 percent H2O2. The bleaching agent was applied to the buccal surface and to the pulp chamber for 10 min. This procedure was repeated 3 times. The specimens were processed histochemically with copper sulfate and rubeanic acid, sectioned longitudinally, and digitalized in a scanner. The area of stained dentin was measured using Image Tool software. Data were analyzed statistically by ANOVA and Tukey's HSD test (?=0.05). There was statistically significant difference (p<0.001) among the untreated groups, CI (0.23 ± 0.26) having the lowest permeability and LI (10.14 ± 1.89) the highest permeability. Among the bleached groups, dentin permeability was increased in all groups of teeth except for 2PM. It may be concluded that bleaching with 38 percent H2O2 affected dentin permeability near the pulp chamber in maxillary anterior teeth and in first and second premolars.
Este estudo avaliou a influência do clareamento interno com peróxido de hidrogênio (H2O2) a 38 por cento na permeabilidade da dentina coronária de dentes anteriores superiores e pré-molares superiores. Quatorze incisivos centrais (IC), incisivos laterais (IL), caninos (C), primeiros (1PM) e segundos (2PM) pré-molares foram seccionados transversalmente e distribuídos em 2 grupos (n=7) sendo: G1: não receberam tratamento e, G2: clareados com aplicação de gel na face vestibular e câmara pulpar por 10 min, repetido 3 vezes. Os espécimes foram processados histoquimicamente por meio de imersão em sulfato de cobre e ácido rubeânico e digitalizados em escaner. A área corada foi aferida (Programa Image Tool). Os dentes que não receberam tratamento, apresentaram diferença estatisticamente significante (p<0,001), sendo o ICS (0,23 ± 0,26) e o ILS (10,14 ± 1,89) os grupo com os menores e os maiores valores de permeabilidade, respectivamente. Quando clareados, a permeabilidade coronária dos grupos dentais foi aumentada, exceto no grupo do 2PM. Concluiu-se que a permeabilidade da dentina coronária nos dentes anteriores superiores e primeiros pré-molares foi alterada pelo clareamento dental interno.
Assuntos
Humanos , Cavidade Pulpar/efeitos dos fármacos , Permeabilidade da Dentina/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Irrigantes do Canal Radicular/farmacologia , Clareamento Dental/métodos , Corantes/farmacologia , Cobre/farmacologia , Permeabilidade do Esmalte Dentário/efeitos dos fármacos , Maxila , Oxidantes/farmacologia , Dente não VitalRESUMO
This aticle sought to evaluate the dentin morphology after irradiation by a Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser, using different chemical substances to irrigate radicular canals: distilled water, 17% ethylenediaminetetraacetic acid plus Cetavlon (EDTAC), 1% sodium hypochlorite, and 2% chlorhexidine. Groups were subdivided according to the protocol of laser application (n=9). The specimens were analyzed by scanning electron microscopy (SEM). No differences were found in dentin morphology when different root thirds were examined. Regardless of the chemical substance used, alterations were more evident in groups in which the surfaces were dried before laser irradiation. Fusion areas, craters, carbonization, and partially exposed tubules were verified. When the irradiation was performed in water, the smear layer was incorporated into the laser-modified surface. Among the specimens irrigated with EDTAC and laser-treated, partial obliteration of dentin tubules due to the laser action was verified; in addition, there was no remaining smear layer on the surfaces. Samples irrigated with sodium hypochlorite followed by laser irradiation demonstrated similar morphology to the samples in the chlorhexidine group, with some fusion areas present and no exposed dentin tubules or fissures. The irradiation from an Nd:YAG laser in the presence of EDTAC solution provided a more favorable surface pattern compared to the other experimental conditions, due to the removal of the contaminated layer and the posterior sealing of dentin tubules.