Effect of Time Lapse on the Diagnostic Accuracy of Cone Beam Computed Tomography for Detection of Vertical Root Fractures.

Accurate and early diagnosis of vertical root fractures (VRFs) is imperative to prevent extensive bone loss and unnecessary endodontic and prosthodontic treatments. The aim of this study was to assess the effect of time lapse on the diagnostic accuracy of cone beam computed tomography (CBCT) for VRFs in endodontically treated dog's teeth. Forty-eight incisors and premolars of three adult male dogs underwent root canal therapy. The teeth were assigned to two groups: VRFs were artificially induced in the first group (n=24) while the teeth in the second group remained intact (n=24). The CBCT scans were obtained by NewTom 3G unit immediately after inducing VRFs and after one, two, three, four, eight, 12 and 16 weeks. Three oral and maxillofacial radiologists blinded to the date of radiographs assessed the presence/absence of VRFs on CBCT scans. The sensitivity, specificity and accuracy values were calculated and data were analyzed using SPSS v.16 software and ANOVA. The total accuracy of detection of VRFs immediately after surgery, one, two, three, four, eight, 12 and 16 weeks was 67.3%, 68.7%, 66.6%, 64.6%, 64.5%, 69.4%, 68.7%, 68% respectively. The effect of time lapse on detection of VRFs was not significant (p>0.05). Overall sensitivity, specificity and accuracy of CBCT for detection of VRFs were 74.3%, 62.2%, 67.2% respectively. Cone beam computed tomography is a valuable tool for detection of VRFs. Time lapse (four months) had no effect on detection of VRFs on CBCT scans.

Effect of Time Lapse on the Diagnostic Accuracy of Cone Beam Computed Tomography for Detection of Vertical Root Fractures

Abstract Accurate and early diagnosis of vertical root fractures (VRFs) is imperative to prevent extensive bone loss and unnecessary endodontic and prosthodontic treatments. The aim of this study was to assess the effect of time lapse on the diagnostic accuracy of cone beam computed tomography (CBCT) for VRFs in endodontically treated dog's teeth. Forty-eight incisors and premolars of three adult male dogs underwent root canal therapy. The teeth were assigned to two groups: VRFs were artificially induced in the first group (n=24) while the teeth in the second group remained intact (n=24). The CBCT scans were obtained by NewTom 3G unit immediately after inducing VRFs and after one, two, three, four, eight, 12 and 16 weeks. Three oral and maxillofacial radiologists blinded to the date of radiographs assessed the presence/absence of VRFs on CBCT scans. The sensitivity, specificity and accuracy values were calculated and data were analyzed using SPSS v.16 software and ANOVA. The total accuracy of detection of VRFs immediately after surgery, one, two, three, four, eight, 12 and 16 weeks was 67.3%, 68.7%, 66.6%, 64.6%, 64.5%, 69.4%, 68.7%, 68% respectively. The effect of time lapse on detection of VRFs was not significant (p>0.05). Overall sensitivity, specificity and accuracy of CBCT for detection of VRFs were 74.3%, 62.2%, 67.2% respectively. Cone beam computed tomography is a valuable tool for detection of VRFs. Time lapse (four months) had no effect on detection of VRFs on CBCT scans.

Resumo Um diagnostico correto e a tempo das fraturas radiculares verticais (FRVs) é essencial para prevenir extensa perda óssea, tratamentos endodônticos e próteses desnecessárias. O objetivo do presente estudo foi avaliar o efeito do tempo decorrido sobre a acurácia diagnóstica da tomografia computadorizada de feixe cônico (TCFC) para detecção de FRVs em dentes de cães tratados endodonticamente. Quarenta e oito dentes incisivos e premolares obtidos de três cães machos adultos tiveram os seus canais tratados. Os dentes foram divididos em dois grupos: no primeiro grupo (n=24) foram artificialmente induzidas FRVs, enquanto no segundo grupo (n=24) os dentes permaneceram intactos. As imagens de TCFC foram obtidas pela unidade NewTom 3G imediatamente após a cirurgia de indução das FRVs e uma, duas, três, quarto, oito, 12 e 16 semanas depois. Três radiologistas cegos para as datas das imagens avaliaram a presença/ausência de FRVs nas imagens de TCFC. Foram calculados os valores da sensibilidade, especificidade e acurácia, sendo os dados analisados por ANOVA e pelo programa SPSS v.16. As acurácias totais de detecção das FRVs imediatamente após sua indução e uma, duas, três, quarto, oito, 12 e 16 semanas depois foram respectivamente de 67,3%, 68,7%, 66,6%, 64,6%, 64,5%, 69,4%, 68,7% e 68%. O efeito do tempo decorrido foi sem significado estatístico (p>0,05). A TCFC produziu valores gerais de sensibilidade, especificidade e acurácia de 74,3%, 62,2% e 67.2%, respectivamente. A tomografia computadorizada de feixe cônico é uma ferramenta valiosa para detecção de FRVs. O tempo decorrido (quatro meses) não teve influência sobre a detecção de FRVs nas imagens de TCFC.

Multiple in vitro analyses of fracture resistance in maxillary central incisors restored with fiber posts.

INTRODUCTION: The resistance to fracture of endodontically treated teeth restored with esthetic post systems has not been extensively researched. This in vitro study compared the fracture patterns of endodontically treated teeth with esthetic post systems with different analysis methods. MATERIALS AND METHODS: A total of 26 recently extracted human maxillary central incisors were decoronated and then endodontically treated. Teeth were restored with quartz fiber posts. All posts were cemented with Panavia dual curing adhesive resin cement and subsequently restored with composite cores. Three methods were used to test fracture resistance. Each specimen was embedded in acrylic resin and then secured in a universal load-testing machine. A compressive load was applied at 135º degree angle at a crosshead speed of 1 mm/min to the long axis of the tooth until fracture occurred. The two other methods, finite element analysis (FEA) and photo elastic study used the same angulation and 90 N force to simulate the first method. The data were then compared. RESULTS: Clinical results indicated that fracture was most likely to occur between core and dentin, and then in the cervical 1/3 of the root. Photo elastic study demonstrated similar results; the highest stresses occurred at the junction of dentin and core contralateral to the side where force was applied. FEA also confirmed these results; however it also showed that the highest stresses arise at the dentin/core junction contralateral to the force point. CONCLUSION: All three techniques reiterate that the risk of fracture is greatest at the cervical dentin/core junction.