External root thermal analysis of three different obturation techniques.

Background: The purpose of this study was to assess the external root surface thermal behavior when submitted to three different obturation techniques. Material and Methods: Forty-five single-rooted premolars were selected, prepared and randomly divided into three groups according to the studied obturation techniques: lateral condensation (LC), single cone technique (SCT) and injectable thermoplasticized technique (IT). Each tooth was placed in a customized apparatus and connected to a thermocouple. A FLIR T650sc infrared thermal camera was used to assess root temperature in a room under controlled temperature and humidity. Temperature values were recorded using the thermal camera and thermocouples before, during and 30, 60, 90, 120, 150s after obturation. Shapiro-Wilk, QQ-plot, Levene's, ANOVA-three-way, Mauchly's sphericity, Box's M and Bonferroni tests were used to assess data. The significance level was set at 5%. Results: Infrared assessment showed significant temperature changes between time intervals, obturation techniques and root thirds. Temperature increase was observed 30s after obturation for STL, LC and IT, followed by a gradual temperature decline, with temperature values similar to the initial temperature at 150s for LC and IT. SCT temperature values only returned to normal 60s after obturation in the apical third and 90s in the middle and cervical thirds. In all techniques, the temperature did not rise above the critical limit of 10°C. Conclusions: All studied obturation techniques increased root surface temperature with IT showing the highest temperature increase. However, the temperature increase does not exceed the acceptable limits, not causing damage to the surrounding tissues. Key words:Endodontics, changes in body temperature, root canal filling, thermography.

Influence of size of field of view (FOV), position within the FOV, and scanning mode on the detection of root fracture and observer's perception of artifacts in CBCT images.

OBJECTIVE: To assess the influence of field of view (FOV) size, scanning position within the FOV and scanning mode on the detection of root fracture and artifact perception. METHODS: Forty single-rooted premolars restored with NiCr and AgPd posts were divided into two groups: fractured and sound. All teeth were scanned using four CBCT scanning protocols varying FOV sizes (80 × 80 mm and 50 × 55 mm) and scanning modes (Standard and High Definition). The sample was positioned within the FOV in two pre-set positions (central and lateral) and in four positions established by the operator (quadrants). Detection of root fracture and artifact perception were assessed by two observers using 5-point and 4-point scales. Sensitivity, specificity, accuracy, and AUC values were calculated and compared by ANOVA two-way and Tukey's test. Chi-square and Fisher's exact test were used to assess artifact perception. The level of significance was set at p < 0.05. RESULTS: The central position within the FOV presented higher sensitivity, specificity, accuracy, and AUC values and differed from the lateral position within the FOV for the studied metal posts (p<0.05). Quadrant 2 presented the best sensitivity, accuracy, and AUC values (p<0.05). The lateral position within the FOV, AgPd posts, quadrants 1 and 3 and protocols 1 (SM, 80 × 80) and 2 (HD, 80× 80) presented higher frequency of artifacts classified as "severe". CONCLUSION: Positioning the object in the center or closer to the anterior periphery of the FOV while using a small FOV improved the detection of root fracture and decreased artifact perception.

Comparison of microtomography and optical coherence tomography on apical endodontic filling analysis.

OBJECTIVES: To comparein vitro differences in the apical filling regarding working length (WL) change and presence of voids and to validate optical coherence tomography (OCT) in comparison with computerized microtomography (µCT) for the detection of failures in the apical filling. METHODS: Forty-five uniradicular teeth with round canals, divided into groups (n = 15) following the obturation protocols: LC (lateral condensation), TMC (thermomechanical compaction) and SC (single cone). Samples were scanned using µCT (parameters: 80 kV, 222 µA, and resolution of 11 µm), OCT (parameters: SSOCT, 1300 nm and axial resolution of 12 µm), and periapical digital radiography. The images were analyzsed by two blind and calibrated observers using ImageJ software to measure the boundary of the obturation WL and voids presence. Categorical and metric data were submitted to inferential analysis, and the validity of the OCT as a diagnostic test was assessed with performance and reliability tests. RESULTS: The WL average remained constant for all obturation techniques and image methods. OCT showed adequate sensitivity and specificity to detect voids in the WL of apical obturations in vitro in comparison with µCT. Both image methods found a higher number of voids for LC technique (µCT p = 0.011/OCT p = 0.002). CONCLUSIONS: OCT can be used in apical obturation voids assessment and the LC technique revealed more voids with larger dimensions.

Termografia infravermelha na odontologia / Infrared thermography in dentistry

A termografia infravermelha consiste em um exame de imagem complementar aplicada na avaliação da temperatura corporal com base na emissão de radiação infravermelha através da pele, podendo auxiliar no diagnóstico ou monitoramento das intervenções terapêuticas. Trata-se de uma técnica não ionizante e não invasiva que capta e registra a distribuição térmica da superfície cutânea avaliada por meio das alterações na microcirculação dos pacientes frente a diferentes condições patológicas. Dentre as aplicações na Odontologia, a termografia pode complementar o exame físico anatômico, visto que apresenta em tempo real condições fisiológicas, de acordo com a temperatura. Esta técnica pode auxiliar no diagnóstico e planejamento do tratamento de alterações orofaciais, como processos inflamatórios e infecciosos na região orofacial, acompanhamento pós-cirúrgico e na avaliação de pacientes com desordens temporomandibulares (DTM). A termografia ainda é pouco utilizada na Odontologia, e protocolos para avaliação de alterações na região de cabeça e pescoço ainda devem ser testados e estabelecidos. Porém, já mostra ser um exame complementar de boa performance na detecção de pontos gatilho da dor, acompanhamento de pacientes de forma não invasiva e como documentação médico-legal.

Infrared thermography consists of a complementary imaging test applied to the assessment of body temperature based on the emission of infrared radiation through the skin, which may aid in the diagnosis or monitoring of therapeutic interventions. It is a non-ionizing and non-invasive technique that captures and records the thermal distribution of the cutaneous surface evaluated by means of the changes in the patients' microcirculation in face of different pathological conditions. Among the applications in Dentistry, thermography can complement the anatomical physical examination, since it presents in real time physiological conditions according to temperature. This technique can help in the diagnosis and planning of the treatment of orofacial alterations, such as inflammatory and infectious processes in the orofacial region, post-surgical follow-up and in the routine evaluation of patients with temporomandibular disorders (TMD). Thermography is still poorly used in Dentistry and protocols for the evaluation of head and neck disorders have yet to be tested and established. However, it already shows up as a good complementary examination for the detection of pain trigger points, follow-up of patients in a non-invasive way, and as medical-legal documentation.