Few studies have investigated cracks involving the pulp chamber walls or floor. The purpose of this study was to create a classification system for intrapulpal cracks and analyze associated clinical characteristics. Retrospective analysis included 52 teeth confirmed to have an intrapulpal crack. The classification system describes the crack based upon its location within the pulpal walls and floor. Documentation consisted of demographic, subjective and objective examination data. Chi-squared analysis tested associations with the intrapulpal crack classifications. Ninety-two percent of intrapulpal cracks run M-D, 75% involve one pulp chamber wall, and 84% terminate at the floor-wall junction or extend into an orifice without involving the pulpal floor. There was a statistically significant (P<0.05) relationship between the location of the intrapulpal crack and tooth type as well as between the classification system and bite test and transillumination. The classification system was adaptable to clinical practice and provides insight into these challenging situations.

Few studies have reported the incidence or prevalence of cracked teeth with pulpal involvement. No attempts have been made to evaluate the prevalence or clinical predictors for intrapulpal cracks. The purpose of this study was to investigate the prevalence of intrapulpal cracks in first and second mandibular molars and to determine if clinical findings are predictive for the existence of intrapulpal cracks. First and second mandibular molars (190) requiring non-surgical root canal treatment at the VCU Graduate Endodontic Practice between February 15, 2013 and August 15, 2013 were analyzed retrospectively. Teeth were transilluminated, stained, and inspected for intrapulpal cracks using a dental microscope. Data gathered included: demographics, subjective and objective information regarding the chief complaint to include bite stick test, transillumination, probing depths greater than 4mm, existing restorations, and diagnosis. Chi-square and logistic regression were performed (p<0.05). The prevalence of intrapulpal cracks in first and second mandibular molars combined was 9% (17/190, 95%CI= 5.7% to 13.9%). The prevalence was 7% for 1st molars and 13% for 2nd molars. There was no statically significant difference in the prevalence between first and second mandibular molars. Individual characteristics predictive for the existence of intrapulpal cracks were age, probing depth greater than 4mm, transillumination and a positive Tooth Slooth™ test (all p<0.05). Staining of the pulp chamber after access identified only one of 17 intrapulpal cracks. Staining of the pulp chamber did not significantly increase the ability to identify intrapulpal cracks. Neither diagnosis, sex, nor existing restorations were significant predictors for intrapulpal cracks. Probing depth greater than 4mm, age over 40 and a positive Tooth Slooth™ test were conjointly significant for predicting intrapulpal cracks.

Cracked teeth have long presented a diagnostic challenge. Previous investigators have considered possible predictive factors, many of which revolve around the tooth’s restorative characteristics. Few have investigated the restorative status of teeth with cracks extending into the pulp chamber. The purpose of this investigation was to determine the prevalence of the different types of restorations present in intrapulpally cracked teeth and determine any other restorative factors that may aid in predicting the presence or extent of an intrapulpal crack. Intrapulpally cracked molars requiring endodontic therapy at the VCU Graduate Endodontic Practice were included in this study. For each tooth, the type of restorative material present and surfaces involved were recorded. The Restoration Volume Proportion (RVP) was calculated to accurately quantify the size of the restoration present. Pulpal and periapical diagnoses, and intrapulpal crack classification were also recorded. Chi squared analysis and logistic regression were used to determine any significant associations. This study included 43 teeth. The study population was 65% female and the average age was 56. Of the various restoration types evaluated, 73% of teeth presented with amalgams, 12% with composites. Class I restorations were 61% of the sample. The most frequently occurring restoration size by volume was a “small” restoration. The most commonly involved teeth were the maxillary 1st molar and mandibular 2nd molar. A significant association was found between restoration size and crack classification suggesting that teeth with larger restorations had a higher incidence of coronal cracks while those with smaller restorations had a higher incidence of radicular cracks. Restoration classification and pulpal walls involved were also significantly associated suggesting that Class II restorations were most frequently associated with cracks involving a single pulpal wall while Class I restorations were evenly associated with one and two wall cracks. Other significant associations were found between tooth type and pulpal walls involved and between restoration surfaces and pulpal wall classification. This study found several significant associations between restoration characteristics and intrapulpal cracks. Further research may continue to reveal how a tooth’s restorative status may influence its risk for the presence of an intrapulpal crack.

Cracked teeth may be difficult to diagnose. Craze lines rarely become symptomatic or require treatment. Cracks in the enamel and dentin alone may or may not become symptomatic and require restorative treatment. However, cracks extending into the enamel, dentin, and pulp chamber provide an avenue for bacteria to establish infection and this commonly results in symptoms and the need for endodontic and restorative treatment. The published endodontic literature has limited information regarding the prevalence or predictive factors for cracks extending into the pulp chamber of teeth. The purpose of this study was to determine the prevalence and classification of intrapulpal cracks in maxillary premolars and to identify factors that may aid in diagnosing the existence and extent of a crack. The cracks were classified according to the Intrapulpal Crack Classification System proposed by Detar in 2014. All maxillary premolar teeth treatment planned for non-surgical root canal therapy (NSRCT) or retreatment (RETX) at Virginia Commonwealth University (VCU) Graduate Endodontic Practice from January 2014 through February 2015 were included in the study after obtaining patient consent. Teeth were examined visually, stained, and examined microscopically for the presence of an intrapulpal crack. Demographic information, subjective data associated with the chief complaint, objective results of diagnostic testing (percussion, palpation, bite stick test, transillumination, probing depths), existing restorations, pulpal diagnosis, and periapical diagnosis were analyzed using chi-square and multiple logistic regression (P

Resumo: O objetivo do presente estudo foi investigar a influência da pressão intrapulpar e da profundidade dentinária sobre o desempenho adesivo de dois agentes de união à dentina, Single Bond (3M ESPE, St. Paul, MN, EUA) e Clearfil SE Bond (Kuraray, Tokyo, Japão), aplicados in vitro e in vivo. Quarenta e oito prémolares superiores hígidos foram selecionados e os pares pertencentes aos mesmos pacientes foram aleatoriamente distribuídos em 4 grupos experimentais de acordo com o sistema adesivo e a pressão intrapulpar, presente ou ausente. Dos dentes pertencentes ao mesmo par, um foi tratado in vivo e o outro in vitro. A ausência ou presença de pressão intra-pulpar foi determinada in vivo pelo uso de anestésicos locais com ou sem vasoconstritor, respectivamente. In vitro, os dentes foram mantidos sob pressão hidrostática de 15 cm de água por 24 horas. Cavidades de classe I foram preparadas e os sistemas adesivos aplicados de acordo com a recomendação dos fabricantes, seguidos da restauração incremental em resina composta. Para os dentes tratados in vitro, os mesmos procedimentos restauradores foram realizados após 6 meses de armazenagem em solução contendo timol 0,1%. Espécimes com área de secção transversal de 1 mm2 foram obtidos e submetidos ao ensaio mecânico de microtração. In vivo, ambos os sistemas adesivos apresentaram desempenho adesivo comparável, enquanto in vitro, o sistema Single Bond foi superior ao sistema Clearfil SE Bond. Esse último não foi influenciado por nenhuma das variáveis estabelecidas no estudo, ou seja, aplicação in vitro ou in vitro, presença de pressão intrapulpar e profundidade em dentina. O sistema Single Bond aplicado sob pressão intrapulpar positiva sofreu variação significante de resistência de união em função da profundidade da dentina, ou seja, em dentina profunda seu desempenho adesivo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The purpose of this study was to evaluate the influence of intrapulpal pressure and dentin depth on bond strength of an etch-and-rinse and a self-etching bondin agent to dentin in vitro and in vivo. Twenty-four pairs of sound upper premolars were randomly divided into four groups (n=6) according to the dentin bonding agent, Single Bond (3M ESPE, St. Paul, MN, EUA) and Clearfil SE Bond (Kuraray, Tokyo, Japan), and the presence or absence of intrapulpal pressure. Each tooth of the pair from the same subject was further designated to be treated in vivo or in vitro. The intrapulpal pressure was controlled in vivo by the delivery of local anesthetics containing or not a vasoconstrictor. The in vitro intrapulpal pressure was achieved by keeping the teeth under a hydrostatic pressure (15 cm H2O) for 24 h. Class I cavities were prepared and the dentin bonding agents applied according to the manufacturers' directions, followed by the incremental resin restoration. For the teeth treated in vitro, the same restorative procedures were performed after 6 monthstorage in 0.1% tymol. Beams with 1 mm2 cross-sectional area were prepared and microtensile tested. The dentin bonding agents produced similar bond strengths when applied in vivo, while Single Bond performed better in vitro. Only the latter was influenced by the presence of intrapulpal pressure, however this was significant only when the bond strengths were stratified according to the dentin depth. This means that in deep dentin, the adhesive performance of this bonding agent was significantly inferior compared to superficial dentin, both in vitro and in vivo. In conclusion, the intrapulpal pressure did not influence the ability of the self-etching bonding agent to bond to dentin as well as its application in vivo or in vitro. The etch-and-rinse adhesive, on the other hand, performed better in vitro and was negatively... (Complete abstract click electronic access below)

O objetivo do trabalho foi investigar múltiplos aspectos relacionados ao pré-aquecimento da resina composta anterior à fotoativação: o grau de conversão e a cinética da polimerização em função da temperatura de polimerização, tempo de fotoativação e profundidade; o desempenho da fonte aquecedora (temperatura máxima, estabilidade térmica do aparelho e variações de temperatura ao pré-aquecer compules) e aspectos clínicos (o efeito de ciclos de pré-aquecimento repetidos e prolongados sobre o grau de conversão, a variação da temperatura intrapulpar in vitro e a variação da temperatura in vivo ao usar resina composta pré-aquecida ou a temperatura ambiente. A conversão de monômeros e os parâmetros de cinética foram determinados através de FTIR-ATR. Os espécimes foram fotoativados por 5, 10, 20 ou 40s entre 3 o e 60 o C. Foram calculados o grau de conversão em tempo real, a taxa máxima de conversão, o tempo em que ocorreu a taxa máxima, e a conversão na taxa máxima. Os dados foram tratados por análise de variância, teste-t e análise de regressão (p &#8804;0,05). O desempenho do dispositivo aquecedor foi medido monitorando-se a mudança de temperatura em tempo real com o auxílio de um termopar tipo-k conectado a um conversor analógico-digital. Os termopares foram colocados no aquecedor e dentro de compules de compósito. Os dados foram analisados com teste t (p &#8804;0,05). Compules (n=5) foram submetidos a um dos ciclos térmicos: Pré-aquecimento repetido (da temperatura ambiente a 60 o C, por 10 vezes) ou Prolongado (24h a 60 o C). O grau de conversão foi medido 24h após os ciclos, com o compósito à temperatura ambiente, seguindo o protocolo descrito acima. Os dados foram tratados por análise de variância e teste de Tukey (p&#8804;0,05). O aumento da temperatura intrapulpar foi medido por um termopar colocado na câmara pulpar de um prémolar contendo uma cavidade de Classe V (com 1mm de espessura de dentina remanescente). O preparo foi preenchido com compósito à temperatura ambiente ou pré-aquecido enquanto a temperatura intrapulpar era continuamente monitorada (n=5). Os dados foram comparados por análise de variância e teste de Tukey (p &#8804;0,05). Para a medida da variação de temperatura in vivo, foram feitos preparos cavitários de 2mm de profundidade em dentes posteriores de um indivíduo (n=3). Uma sonda que mensurava a temperatura foi introduzida no dente preparado em cada procedimento restaurador e durante a inserção da resina composta à temperatura ambiente ou pré-aquecida a 60°C. Os dados foram comparados com análise de variância e teste de Tukey (p &#8804;0,05). Os resultados indicaram que: 1) o pré-aquecimento da resina composta anterior à fotoativação aumenta o grau de conversão, reduz o tempo de fotoativação e resulta em maior taxa de conversão, sem alterar o tempo em que a taxa máxima ocorre; 2) tanto o dispositivo aquecedor quanto os compules atingiram temperaturas inferiores das determinadas pelo fabricante; ao remover o compósito do aquecedor a perda de calor é acentuada ; 3) o grau de conversão não foi afetado por ciclos repetidos e prolongados de pré-aquecimento da resina composta; 4) não houve aumento da temperatura intrapulpar ao serem comparadas as resinas composta à temperatura ambiente e pré-aquecida; 5) a medida da temperatura in vivo revelou que o compósito pré-aquecido a 60 o C fica somente 8 o C acima da temperatura intrabucal; a técnica de pré-aquecimento deve ser usada com cautela. / This work examined multiple aspects of pre-heating dental resin composite prior to light-curing: the monomer conversion and polymerization kinetics as a function of cure temperature, light-exposure duration and depth; the performance of the heating device (maximum temperature, thermal stability of device and temperature change when pre-heating compules); and clinically relevant issues (the effect of repeated and extended pre-heating cycles on conversion; in vitro intrapulpal temperature change and in vivo temperature change when using either room-temperature or pre-heated composite). Monomer conversion and kinetic parameters were determined using FTIR-ATR. Specimens were cured for 5, 10, 20 or 40s between 3 o and 60 o C. Real-time monomer conversion, maximum conversion rate, time into exposure when maximum rate occurred, and conversion at maximum rate were calculated. Data were analyzed using regression analysis, Student's t-tests, and ANOVA with appropriate post-hoc tests (alpha = 0.05). Performance of the heating device was measured by monitoring the real-time temperature change with a K-type thermocouple connected to an analog-to-digital converter. Thermocouples were placed both in the heater and inside composite compules. Data were analyzed using Student t-test (alpha = 0.05). Compules (n=5) were submitted to one of the temperatures cycles: Repeated (from room temperature to 60 o C, 10 times) or Extended pre-heating (24h at 60 o C). Monomer conversion was measured 24h after cycling, with composite at room temperature, following the protocol described above. Data were analyzed using ANOVA and the Tukey-Kramer post-hoc test (alpha = 0.05). Intrapulpal temperature rise was measured by placing a K-type thermocouple in the pulp chamber of a extracted, human premolar, which had a Class V preparation (1mm remaining dentin thickness). The preparation was filled using composite either at room-temperature, or pre-heated while continuously monitoring intrapulpal temperature (n=5). Data were compared using ANOVA and the Tukey-Kramer post-hoc test (&#945; =0.05). For measurement of temperature change in vivo, 2mm deep preparations were made on posterior teeth of a live human subject (n=3). Temperature values were recorded by placing a custom-made probe on the tooth preparation after each restorative procedure and during insertion of resin-composite at room temperature or pre-heated to 60°C. Data were compared using a 2-way ANOVA, and Tukey-Kramer post-hoc test (&#945; =0.05). Results indicated that: 1) pre-warming composite prior to polymerization results in greater conversion, requires shorter exposure duration, and enhances maximal rate of conversion without changing the time into the exposure when the maximum rate occurs; 2) either the heating device or the compules achieved lower temperatures than those stated by the manufacturer; composite temperature loss upon removal from the heater was dramatic; 3) neither repeated nor extended pre-heating of composites significantly affected monomer conversion values; 4) no increase in intrapulpal temperature values was observed when comparing room temperature and pre-heated composite; 5) temperature measurement in vivo revealed that composite pre-heated to 60°C attains only 8 o C above intraoral temperature upon delivery; thus, the composite pre-heating technique should be used with caution.

O objetivo do trabalho foi investigar múltiplos aspectos relacionados ao pré-aquecimento da resina composta anterior à fotoativação: o grau de conversão e a cinética da polimerização em função da temperatura de polimerização, tempo de fotoativação e profundidade; o desempenho da fonte aquecedora (temperatura máxima, estabilidade térmica do aparelho e variações de temperatura ao pré-aquecer compules) e aspectos clínicos (o efeito de ciclos de pré-aquecimento repetidos e prolongados sobre o grau de conversão, a variação da temperatura intrapulpar in vitro e a variação da temperatura in vivo ao usar resina composta pré-aquecida ou a temperatura ambiente. A conversão de monômeros e os parâmetros de cinética foram determinados através de FTIR-ATR. Os espécimes foram fotoativados por 5, 10, 20 ou 40s entre 3 o e 60 o C. Foram calculados o grau de conversão em tempo real, a taxa máxima de conversão, o tempo em que ocorreu a taxa máxima, e a conversão na taxa máxima. Os dados foram tratados por análise de variância, teste-t e análise de regressão (p &#8804;0,05). O desempenho do dispositivo aquecedor foi medido monitorando-se a mudança de temperatura em tempo real com o auxílio de um termopar tipo-k conectado a um conversor analógico-digital. Os termopares foram colocados no aquecedor e dentro de compules de compósito. Os dados foram analisados com teste t (p &#8804;0,05). Compules (n=5) foram submetidos a um dos ciclos térmicos: Pré-aquecimento repetido (da temperatura ambiente a 60 o C, por 10 vezes) ou Prolongado (24h a 60 o C). O grau de conversão foi medido 24h após os ciclos, com o compósito à temperatura ambiente, seguindo o protocolo descrito acima. Os dados foram tratados por análise de variância e teste de Tukey (p&#8804;0,05). O aumento da temperatura intrapulpar foi medido por um termopar colocado na câmara pulpar de um prémolar contendo uma cavidade de Classe V (com 1mm de espessura de dentina remanescente). O preparo foi preenchido com compósito à temperatura ambiente ou pré-aquecido enquanto a temperatura intrapulpar era continuamente monitorada (n=5). Os dados foram comparados por análise de variância e teste de Tukey (p &#8804;0,05). Para a medida da variação de temperatura in vivo, foram feitos preparos cavitários de 2mm de profundidade em dentes posteriores de um indivíduo (n=3). Uma sonda que mensurava a temperatura foi introduzida no dente preparado em cada procedimento restaurador e durante a inserção da resina composta à temperatura ambiente ou pré-aquecida a 60°C. Os dados foram comparados com análise de variância e teste de Tukey (p &#8804;0,05). Os resultados indicaram que: 1) o pré-aquecimento da resina composta anterior à fotoativação aumenta o grau de conversão, reduz o tempo de fotoativação e resulta em maior taxa de conversão, sem alterar o tempo em que a taxa máxima ocorre; 2) tanto o dispositivo aquecedor quanto os compules atingiram temperaturas inferiores das determinadas pelo fabricante; ao remover o compósito do aquecedor a perda de calor é acentuada ; 3) o grau de conversão não foi afetado por ciclos repetidos e prolongados de pré-aquecimento da resina composta; 4) não houve aumento da temperatura intrapulpar ao serem comparadas as resinas composta à temperatura ambiente e pré-aquecida; 5) a medida da temperatura in vivo revelou que o compósito pré-aquecido a 60 o C fica somente 8 o C acima da temperatura intrabucal; a técnica de pré-aquecimento deve ser usada com cautela. / This work examined multiple aspects of pre-heating dental resin composite prior to light-curing: the monomer conversion and polymerization kinetics as a function of cure temperature, light-exposure duration and depth; the performance of the heating device (maximum temperature, thermal stability of device and temperature change when pre-heating compules); and clinically relevant issues (the effect of repeated and extended pre-heating cycles on conversion; in vitro intrapulpal temperature change and in vivo temperature change when using either room-temperature or pre-heated composite). Monomer conversion and kinetic parameters were determined using FTIR-ATR. Specimens were cured for 5, 10, 20 or 40s between 3 o and 60 o C. Real-time monomer conversion, maximum conversion rate, time into exposure when maximum rate occurred, and conversion at maximum rate were calculated. Data were analyzed using regression analysis, Student's t-tests, and ANOVA with appropriate post-hoc tests (alpha = 0.05). Performance of the heating device was measured by monitoring the real-time temperature change with a K-type thermocouple connected to an analog-to-digital converter. Thermocouples were placed both in the heater and inside composite compules. Data were analyzed using Student t-test (alpha = 0.05). Compules (n=5) were submitted to one of the temperatures cycles: Repeated (from room temperature to 60 o C, 10 times) or Extended pre-heating (24h at 60 o C). Monomer conversion was measured 24h after cycling, with composite at room temperature, following the protocol described above. Data were analyzed using ANOVA and the Tukey-Kramer post-hoc test (alpha = 0.05). Intrapulpal temperature rise was measured by placing a K-type thermocouple in the pulp chamber of a extracted, human premolar, which had a Class V preparation (1mm remaining dentin thickness). The preparation was filled using composite either at room-temperature, or pre-heated while continuously monitoring intrapulpal temperature (n=5). Data were compared using ANOVA and the Tukey-Kramer post-hoc test (&#945; =0.05). For measurement of temperature change in vivo, 2mm deep preparations were made on posterior teeth of a live human subject (n=3). Temperature values were recorded by placing a custom-made probe on the tooth preparation after each restorative procedure and during insertion of resin-composite at room temperature or pre-heated to 60°C. Data were compared using a 2-way ANOVA, and Tukey-Kramer post-hoc test (&#945; =0.05). Results indicated that: 1) pre-warming composite prior to polymerization results in greater conversion, requires shorter exposure duration, and enhances maximal rate of conversion without changing the time into the exposure when the maximum rate occurs; 2) either the heating device or the compules achieved lower temperatures than those stated by the manufacturer; composite temperature loss upon removal from the heater was dramatic; 3) neither repeated nor extended pre-heating of composites significantly affected monomer conversion values; 4) no increase in intrapulpal temperature values was observed when comparing room temperature and pre-heated composite; 5) temperature measurement in vivo revealed that composite pre-heated to 60°C attains only 8 o C above intraoral temperature upon delivery; thus, the composite pre-heating technique should be used with caution.