Intraoral Periapical Research Articles

Determination of working length of root canal

Background: This study was undertaken to determine the working length of root canal by microprocessor controlled impedance quotient apex locator and conventional radiographic method. Methods: Patients whose teeth were to be extracted were selected for this study. A total of 100 teeth in the same or different patients were identified. Biomechanical preparation of the canal was done for smooth negotiation of the entire canal. The electrode of the Root ZXTM was attached to the selected file and the length adjusted till the beep of the Root ZXTM indicated the apical foramen. The electrode was removed but the file was stabilized with the help of soft gutta percha. An intraoral periapical (IOPA) radiograph was taken using basic guidelines. The tooth was then extracted under local anaesthesia along with the file in the tooth. A window was cut on one surface of the root apex approximately 4mm from the apex to expose the root canal. The file tip was identified. The distance of the file tip from the apex was measured under 3X magnification and the reading recorded. Similarly the distance from the file tip to the radiographic apex was measured on the radiograph under magnification and the reading recorded. All the readings were tabulated. The actual distances measured between the extracted tooth, the electronic apex locator and on the radiograph were compared using a paired “t” test to determine the accuracy of each method in relation to the minor diameter. Result: It was observed that the radiographic method had a significant variation from the electronic method when compared to the actual measurement on the extracted tooth. Conclusion: The electronic method is a more accurate method as compared to radiographic method for determination of working length of the root canal.

Evaluation of surface radiation dose to the thyroid gland and the gonads during routine full-mouth intraoral periapical and maxillary occlusal radiography.

Aim:The quantitative aspects of radiation doses to critical organs can help the dental professionals to take the necessary radiation protective measures as deemed necessary and can help the general public to allay radiation exposure fear in dental radiography, if any. Our study determines the surface radiation dose to thyroid and gonads in full-mouth intraoral periapical (IOPA) and maxillary occlusal radiography.Materials and Methods:A total number of 120 subjects participated in the study. The surface radiation dose was estimated to the thyroid gland and the gonads in full-mouth IOPA radiography using 10 IOPA (E speed films) and in maxillary occlusal radiography. The measurements were calculated using a digital pocket dosimeter (PD-4507).Results:The average dose at the thyroid gland level during full-mouth intraoral and maxillary occlusal radiography was estimated to be 10.93 mRads (1.093 × 10-2 mGy) and 0.4 mRads (4.0 × 10-2 mGy), respectively. The average surface radiation dose at the gonadal region during a full mouth intraoral and maxillary occlusal radiography was estimated to be 1.5 mRads (1.5 × 10-2 mGy) and 0.15 mRads (1.5 × 10-3 mGy), respectively.Conclusion:Our results suggest that although the radiation exposure doses to critical organs namely thyroid and gonads is within the safe limits still precautionary measures for these organs are advocated.

MULTI RESOLUTION BASED IMAGE REGISTRATION TECHNIQUE FOR MATCHING DENTAL X-RAYS

This paper presents a new technique to assess the bone formation after periapical dental surgery. The proposed technique consists of two main stages: image registration and spectral subtraction stages. Image registration is used to avoid projection errors produced due to nonstandardization of X-ray scanners. Wavelet coefficients are used instead of grey values for registering the images. Coarse to fine strategy with four levels of resolutions is used to speed up the process. The second stage is the spectral subtraction stage. It is used to yield the difference image between pre- and post-operative images which represents the bone gain or bone loss with light and dark areas, respectively. Algorithm has been applied on a number of pre- and post-surgery intra oral periapical (IOP) dental X-ray images. Mean and root mean square error (RMSE) are computed to assess the quality of registration technique. The technique presented here is compared with grey level based method; results show that proposed technique outperforms conventional grey level method based on dyadic sampling.

Evaluation of Proximal Alveolar Bone Level Changes During Orthodontic Treatment - A Comparative Clinical Study

The aim of this clinical study was to evaluate the iatrogenic effect of orthodontic treatment on interproximal crestal alveolar bone and to the compare the changes in cases treated by Preadjusted Edgewise Appliance and those treated by the Begg Appliance. Two study groups comprising of 10 patients each were treated with either of the appliances. The radiographic method - Absolute technique as described by Albander et al-was used for quantification of crestal alveolar bone. Two radiographic examinations were performed, one at the start of treatment and second at the end of the orthodontic treatment. Each included two intra-oral periapical (IOPA) radiographs of the maxillary anterior region (right canine to left canine) taken using the paralleling technique. Measurements were made on the IOPA films and the results evaluated.