Retrospective radiographic study comparing unintentional extrusion of gutta-percha versus sealer on teeth with periapical radiolucency.

OBJECTIVES: The purpose of the present study was the radiographic evaluation of endodontically treated teeth presenting periapical radiolucency and unintentional overfilling with gutta-percha or sealer on treatment outcome and persistence of the extruded materials. METHOD AND MATERIALS: After assessment using periapical index (PAI), 202 roots filled with gutta-percha and zinc oxide eugenol sealer (Roth 811, Roth International), exhibiting unintentional overfilling and periapical radiolucency were selected. All cases had at least 1 year follow-up. Type of extruded material, periapical status, and removal/persistence of the extruded material were evaluated by two independent observers. Data were statistically analyzed using logistic and linear regression analysis. RESULTS: Tooth location (P <.001), follow-up period (P <.001), and type of extruded material (P =.004) significantly influenced treatment outcomes. Specifically, posterior roots exhibited better outcomes compared to anterior, and cases with overfilling of sealer showed superior healing potential compared to those with gutta-percha overfilling. Additionally, longer recall periods were associated with improved treatment success. It is also seen that the type of extruded material (P <.001) and follow-up period (P <.001) have significantly affected the presence of extruded material in the follow-up radiograph. The persistence of extruded material was greater when gutta-percha was extruded as well as extruded materials were less detected when the follow-up period was longer. CONCLUSION: Teeth with periapical radiolucency and unintentional overfilling require longer follow-up intervals for effective monitoring of healing. Treatment outcome was associated with the type of extruded materials used in the present study. The persistence of those materials in the periapex did not affect healing.

Fusion of a maxillary third molar with a supernumerary fourth molar: A case report.

Key Clinical Message: Dental fusion should be included in differential diagnosis when panoramic radiograph reveals changes in tooth shape or size. The use of specialized dental photographic techniques can augment the dentists' knowledge and awareness of such conditions. Abstract: Dental fusion of impacted teeth may show up as a change in tooth shape and size on the first radiographic examination. This report presents an impacted maxillary third molar fused with a peg-like distomolar in a 20-year-old male. The patient presented with symptoms of localized periodontitis distal to the second molar, and radiographic examination revealed abnormal dental structure of the third molar. Surgical extraction of the impacted molar was the treatment of choice. The final diagnosis of fusion was based on data from ex vivo CBCT, photographs of the extracted tooth, and extracted tooth's sections using polarizing filters. Two-dimensional radiographs may conceal special dental anatomies. Visualization of such cases using CBCT and dental photography serves to educate dentists and reduce postoperative complications. Knowledge and awareness of possible dental abnormalities are of utmost importance for successful treatment planning.

Pre-restorative crown lengthening surgery: influence of restorative treatment timing on clinical outcomes-a pilot study.

OBJECTIVES: Aim of this study was to assess the influence of restorative treatment timing on the periodontal, patient and operator-reported outcomes following crown lengthening surgery (CLS). MATERIALS AND METHODS: Eighteen study participants requiring CLS were divided into two groups based on prosthetic rehabilitation timing (6 or 14 weeks postoperatively). Clinical parameters were recorded around treated and neighboring teeth before and after surgery, 6 and 14 weeks postoperatively, at prosthesis delivery, and three and six months after. Soft tissue and radiographic bone changes were evaluated. Patients assessed their perception of the procedure by means of a questionnaire. The final treatment outcome was rated by both patients and prosthodontists. RESULTS: CLS resulted in statistically significant and stable apical displacement of the gingival margin, at both treated and adjacent sites. Plaque and bleeding scores remained low throughout. No statistically significant differences were observed between groups for any clinical or radiographic parameter examined. Healing was uneventful and treatment outcome was satisfying for both patients and prosthodontists, without statistically significant differences between groups. CONCLUSIONS: The present study has been characterized as pilot, because it was not possible to reach the sample size indicated by the a priori power analysis. CLS is an effective pre-prosthetic procedure as long as it is performed under a certain surgical protocol which predicts for at least a 3 mm distance between bone crest and the flap margin at suturing. Within the limitations of this study, six weeks after surgery may be an adequate healing time for the onset of prosthetic restoration. CLINICAL RELEVANCE: Crown lengthening surgery is commonly performed in daily clinical practice with the aim to restore teeth with short clinical crowns. Based on periodontal, patient and operator-reported criteria, 6 weeks after CLS may be adequate healing time before the onset of prosthetic restoration. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03947658, 13/05/2019, retrospectively registered.

Prevalence and risk indicators of peri-implantitis: a university based cross-sectional study.

OBJECTIVES: To assess the prevalence of peri-implantitis and identify risk and protective indicators of peri-implantitis in a population that underwent implant therapy in a university dental clinic. METHOD AND MATERIALS: Randomly selected patients from a postgraduate university dental clinic were invited to participate. Clinical and radiographic examinations were recorded. Peri-implantitis was defined as the presence of bleeding and/or suppuration on probing, probing depths of ≥ 6 mm, and bone loss ≥ 3 mm. Patient-, implant-, and bone- related factors were recorded and analyzed using a multivariate logistic regression analysis. RESULTS: A total of 355 dental implants placed in 108 patients and exhibiting at least 1 year loading time were included. The prevalence of peri-implantitis was 21.3% at patient-level, while 10.7% at implant-level. Simultaneous guided bone regeneration (OR 2.76, 95% CI 1.07-7.12, P = .035), recurrent periodontitis (OR 3.11, 95% CI 1.02-9.45, P = .045) and significant medical history (OR 2.86, 95% CI 1.08-7.59, P = .034) were identified as risk indicators for peri-implantitis. The mean peri-implant bone loss was estimated to be 2.18 ± 1.57 mm for the total number of implants, whereas implants diagnosed with peri-implantitis demonstrated 4.42 ± 1.12 mm in a time period between 12 to 177 months. CONCLUSION: Within the limitations of the study, the prevalence of peri-implantitis in a cohort receiving dental implant therapy at a university dental clinic was 10.7% at implant level and 21.3% at patient level. Patient-reported systemic comorbidities and recurrent periodontitis as well as implants placed in ridge augmented sites were associated with greater risk of peri-implantitis.

Examination of Irrigant Flow on a Tooth With Internal Root Resorption by Using a Computational Fluid Dynamics Model.

OBJECTIVE: This study investigated the flow of an endodontic irrigant in a single-rooted tooth with internal root resorption (IRR). METHODS: A simulation of a prepared central incisor with internal root resorption was created and irrigation with a 30-G needle was performed. The fluid pattern of the irrigant was evaluated using a Computational Fluid Dynamics model. In addition, the effects of the needle-insertion depth in the root canal and the size of root resorption on the fluid flow and the wall shear stress (WSS) values were assessed. The IRR was placed immediately below the canal orifice. RESULTS: Inadequate irrigant washout was observed inside the resorption cavity when the needle was positioned 1 mm from the working length while placing the needle slightly above the resorption cavity resulted in significant irrigant circulation inside the resorption cavity. Moreover, when the needle was placed slightly above the defect, the calculated WSS values in the resorption cavity walls were significantly higher (approximately 20 times higher in every case). In cases where the needle was placed 1 mm from the working length, the average and maximum WWS values were between 3 Pa and 51 Pa, while in cases where the needle was placed coronal to the IRR, the values were between 55 Pa and 528 Pa. The radius of the resorption cavity did not affect the irrigant flow patterns. CONCLUSION: During the endodontic treatment of cases with internal root resorption, complementary irrigations with the needle tip placed slightly above the resorption cavity should be followed to better debride the root canal.

Micro-Computed Tomographic Evaluation of Canal Transportation and Centering Ability of 4 Heat-Treated Nickel-Titanium Systems.

INTRODUCTION: This study aimed to evaluate and compare canal transportation and centering ability of 4 different root canal preparation systems produced with thermal treatments by means of micro-computed tomographic imaging. METHODS: Eighty mesial canals of human extracted mandibular molars were selected based on similar morphologic parameters and were randomly assigned to 4 experimental groups (n = 20) according to the canal instrumentation technique: HyFlex CM (HCM [Coltène-Whaledent, Allstätten, Switzerland]), HyFlex EDM (HEDM [Coltène-Whaledent]), WaveOne Gold (WOG [Dentsply Sirona, Ballaigues, Switzerland]), and OneCurve (OC [Micro-Mega, Besancon, France]). The specimens were scanned before and after root canal preparation using X-ray micro-computed tomographic imaging at a resolution of 19.9 µm. Apical transportation and centering ability were then analyzed at 3 different levels: 3 mm, 5 mm, and 7 mm from the apex, representing the apical, midroot, and coronal thirds of the root, respectively. One-way analysis of variance and Kruskal-Wallis tests were used to statistically compare the groups. The significance level was set at 5%. RESULTS: HCM caused less canal transportation than WOG at the 3-mm level in both the buccal and lingual canals (P < .05). Also, HCM resulted in less canal transportation than WOG and OC at the 7-mm level regarding lingual canals. No statistically significant differences were recorded between the groups when the mean centering ratios were compared. CONCLUSIONS: The 4 evaluated systems safely prepared root canals causing minimal canal transportation and producing relatively centered preparations. In terms of canal transportation, HCM performed better than WOG at the apical level and better than WOG and OC at the coronal level.

Digital subtraction radiography in detection of vertical root fractures: accuracy evaluation for root canal filling, fracture orientation and width variables. An ex-vivo study.

OBJECTIVE: Ex-vivo evaluation of the detectability of vertical root fractures (VRFs) using digital subtraction radiography (DSR) and conventional digital periapical radiography (CDPR); investigation of the effect of root canal filling, x-ray angulation, and thickness of the VRF in the diagnostic accuracy. MATERIALS AND METHODS: Sixty root canals were mechanically prepared and radiographed either with a gutta-percha root canal filling or without, at 0o and ± 10o. VRFs were introduced with a universal testing machine. The width and angulation of the fracture line with the radiographic beam were calculated. DSR was performed comparing radiographs obtained prior to and after the VRF induction. Five examiners evaluated the resultant images and analysis was performed using receiver operator characteristic (ROC) statistics and binary logistic regression tests. RESULTS: No significant differences in sensitivity, specificity, and the areas under the ROC curves (AUC) between the CDPR and DSR were detected (p > 0.05), except for root canal filled teeth where the AUC for DSR was higher (p < 0.05). Using DSR, a VRF was 1.3 times more likely to be diagnosed [95% confidence intervals (CI): 1.045-1.59; p = 0.018]. A correct diagnosis was 2.399 times more likely to occur in non-filled teeth regardless of the radiographic technique (95% CI 1.940-2.965; p = 0). The regression coefficients were positive for width and negative for angle. CONCLUSIONS: DSR showed a better diagnostic accuracy of VRFs compared with CDPR, in single root canal filled teeth. The angulation, the width, and the presence of a root canal filling affected the diagnostic potential. CLINICAL RELEVANCE: DSR is a cost- and time-effective imaging technique that could contribute in early diagnosis of VRFs.

In Vitro Comparative Study of the Influence of Instrument Taper on the Fracture Resistance of Endodontically Treated Teeth: An Integrative Approach-based Analysis.

INTRODUCTION: The objective of this study was to examine the influence of instrument taper on the fracture resistance of endodontically treated roots under in vitro experimental conditions. METHODS: In total, 58 maxillary canines complying with the inclusion criteria were sectioned at approximately 13 mm from the apex. The roots were standardized with respect to the buccolingual-mesiodistal diameter and weight before being randomly distributed into 3 experimental groups (n = 14) and 1 control group (n = 16). The roots in group 1 were instrumented with hand files up to file 40/.02 and groups 2 and 3 with Mtwo (VDW, Munich, Germany) rotary files up to files 40/.04 and 40/.06, respectively. After mechanical preparation, the roots were obturated with gutta-percha and sealer. Roots in group 4 acted as uninstrumented controls. A vertical load was applied to each specimen using a universal testing machine until the roots fractured. Data were statistically analyzed by introducing an innovative approach integrating 1-way analysis of variance, confirmatory factor analysis, and regression analysis. RESULTS: The mean fracture load was 357.47 ± 110.54 N for the control group, 338.86 ± 105.23 N for group 1, 297.74 ± 77.31 N for group 2, and 280.10 ± 68.51 N for group 3. However, only the difference between group 3 and the control group was statistically significant (P < .05). CONCLUSIONS: After instrumentation using hand files up to file 40/.02 and rotary files up to files 40/.04 and 40/.06, only the last appeared to change the fracture resistance of endodontically treated roots.

A new methodology for the measurement of the root canal curvature and its 3D modification after instrumentation.

OBJECTIVE: In this study, the three-dimensional (3D) modification of root canal curvature was measured, after the application of Reciproc instrumentation technique, by using cone beam computed tomography (CBCT) imaging and a special algorithm developed for the 3D measurement of the curvature of the root canal. MATERIALS AND METHODS: Thirty extracted upper molars were selected. Digital radiographs for each tooth were taken. Root curvature was measured by using Schneider method and they were divided into three groups, each one consisting of 10 roots, according to their curvature: Group 1 (0°-20°), Group 2 (21°-40°), Group 3 (41°-60°). CBCT imaging was applied to each tooth before and after its instrumentation, and the data were examined by using a specially developed CBCT image analysis algorithm. RESULTS: The instrumentation with Reciproc led to a decrease of the curvature by 30.23% (on average) in all groups. CONCLUSIONS: The proposed methodology proved to be able to measure the curvature of the root canal and its 3D modification after the instrumentation.

Factors Affecting the Outcome of Non-Surgical Endodontic Treatments Performed by Undergraduate Students in a Greek Dental School.

OBJECTIVE: To evaluate the outcome of initial endodontic treatments performed by undergraduate students in a Greek dental school and to determine the factors that may impact the treatment outcome. METHODS: From a randomly selected sample of 677 non-surgical endodontic treatments performed between 2012 and 2015, follow-up appointments were scheduled with patients whose dental records matched the inclusion criteria. After clinical and radiographic examination, the treatment outcome was classified as 'success' (healed/healing) or 'failure' (uncertain/unsatisfactory healing). The statistical analysis of the data was performed using generalized estimating equations. Intra-examiner and inter-examiner agreements were checked with the intraclass correlation coefficient and with Cohen's kappa. The statistical significance level was set at P<0.05. RESULTS: A total of 244 teeth (349 roots) were included for further analysis, and the mean follow-up period was 2.8 years. Overall, the success rate for the treated roots was 72.8%. Μultivariate analysis revealed four decisive factors as having a positive impact on the outcome, namely, the absence of voids within the root fillings (P<0.001), the absence of pre-operative periapical lesions (P=0.001), the extension of the root filling material by 0-2 mm from the radiographic apex (P<0.001) and the root type (anterior roots: P=0.015 and premolar roots: P=0.011). The association of gender, arch, pulp status and type of coronal restoration with the outcome was not statistically significant (P>0.05). Moreover, when the outcome according to pre-operative periapical status and the technical variables of root fillings (apical extension and density) was investigated, roots without periapical lesion, with a root filling material extended 0-2 mm within the apex and without voids revealed the highest success rate (94.5%). CONCLUSION: The success rate of non-surgical endodontic treatments performed in a Greek dental school was in the range of those reported in other studies. The pre-operative periapical status, technical variables of root fillings (apical extension and density) and root type were regarded as significant prognostic factors of the outcome.

Quality of Root Canal Fillings Performed by Undergraduate Students and the Related Factors on the Treatment Outcome: A 2- to 5-Year Follow-Up.

OBJECTIVE: To evaluate radiographically the quality of root canal fillings performed by undergraduate students between 2012 and 2015, and to investigate the impact of their quality in correlation with root type, preoperative periapical status, and type of restorative treatment on the treatment outcome. METHODS: Six hundred seventy-seven non-surgical root canal treatments were performed by undergraduate students from the Aristotle University of Thessaloniki at the endodontic department clinics between 2012 and 2015. Two hundred forty-four teeth (349 roots) fulfilled the criteria and were clinically and radiographically re-examined between 2016 and 2017, and the outcome was classified as "success" or "failure." Root canal fillings were radiographically evaluated in terms of apical extension and density. The root filling was classified as acceptable when both parameters were rated as acceptable. Statistical analysis was performed using generalized estimating equations. Pairwise comparisons were performed by the sequential Bonferroni method. Intra-examiner and inter-examiner agreements were checked by the intraclass correlation coefficient and Cohen's kappa. The statistical significance level was set at P<0.05. RESULTS: The percentage of the roots with acceptable root canal fillings was 40.4%. The molar roots demonstrated the lowest rate (30.7%) compared with the anterior (53%, P<0.05) and premolar teeth (43%, P>0.05). The results of the correlation of the quality of the root canal fillings with the root type, preoperative periapical status, type of coronal restoration, and the treatment outcome showed that the unacceptable quality of root canal filling in relation to root or presence of periapical lesion or crown revealed the lowest success rates (47.2%, 40.3%, and 52.3%, respectively). In contrast, results showed that roots with canal fillings of acceptable quality demonstrated success rates close to 90%, regardless of the other variables. CONCLUSION: Within the limitations of the present study, the percentage of radiographically acceptable root canal fillings performed in the undergraduate clinic of the Department of Endodontology at Aristotle University of Thessaloniki was low (40.4%). Results showed that there was a strong association of higher success rates with root fillings of acceptable quality.

Diagnosis of vertical root fractures in endodontically treated teeth utilising Digital Subtraction Radiography: A case series report.

Vertical root fractures are commonly associated with root-filled teeth. Diagnosis is challenging because the clinical signs are not completely pathognomonic, and conventional periapical radiography is often unreliable. Digital subtraction radiography (DSR) is able to detect small radiographic changes between two successive radiographs by subtracting out consistent radiographic elements. Its use could possibly assist in the diagnostic procedure. Four cases are presented to demonstrate the potential use of DSR in the detection of vertical root fractures in endodontically treated teeth. After the digital subtractions had been carried out, a dark line in the body of the roots was distinguishable, raising the possibility of the presence of a vertical root fracture. The use of contrast enhancement and pseudocolouring techniques assisted with the diagnosis of vertical root fractures. DSR proved to be a useful diagnostic tool for the detection of vertical root fractures in these four clinical cases.

Crestal bone resorption after the application of two periodontal surgical techniques: a randomized, controlled clinical trial.

AIM: To radiographically assess, by means of digital subtraction radiography, crestal bone loss following two periodontal surgical techniques, over a period of 6 months. MATERIAL AND METHODS: A total of 30 chronic periodontitis patients participated in this randomized controlled clinical trial and were separated into two groups. Modified Widman flap was applied in the control group and apically positioned flap, without intervention to the bone, in the experimental group. Clinical measurements (plaque index, gingival bleeding index, probing pocket depth and clinical attachment level) were recorded at baseline, 6 weeks, 3 and 6 months after surgery. Digital radiographs were taken at baseline, 1, 3, 6 weeks, 3 and 6 months after surgical treatment and subtracted digitally in pairs. RESULTS: Both groups showed statistically significant improvement of clinical parameters. Statistically significant differences between the two groups were observed only in probing pocket depth (PPD) at 6 weeks interval, where the test group showed more reduction (smallest statistically significant differences observed, SSSDO = 0.64). Both groups showed the same rate of crestal bone resorption. CONCLUSIONS: Bone resorption of the alveolar crest is a phenomenon that is observed as a consequence of periodontal surgical treatment without significant differences between the two techniques. Furthermore, both surgical techniques lead to satisfactory clinical results, indicating that bone removal during periodontal surgical treatment is not always necessary.

Assessment of simulated internal resorption cavities using digital and digital subtraction radiography: a comparative study.

AIM: To compare the diagnostic accuracy of digital radiography with that of digital subtraction radiography in the detection of simulated internal resorption cavities. MATERIALS AND METHODS: Simulated internal resorption cavities of varying sizes were created using round burs in 18 single-rooted teeth with visible pulp chamber, which had been extracted from dentate dry mandibles and split into two halves in a mesio-distal direction. Resorption cavities were created in the buccal half of the root in the cervical, middle, and apical third. Digital radiographs were taken from three different horizontal view angles before and after the creation of the cavities. This process was followed by digital subtraction radiography to evaluate their detection. Seven experienced observers and all specialists in endodontics were asked to examine the digital and digital subtraction images for the presence of the cavities. The data were analyzed using SPSS 14. RESULTS: The overall sensitivity of digital subtraction radiography was superior to digital radiography and with statistically better results for all cavities regardless of their location (cervical, middle, apical third) (P < 0.05). The detection of the cavities was affected by the root third in which they were located. Cavities in the apical third were more easily detected compared with those in the middle or cervical third of the root. Small-sized lesions (0.5 mm, 0.6 mm) in the middle and apical third were more frequent and more easily detected using subtraction imaging. CONCLUSION: Digital subtraction radiography is superior to digital radiography for the detection and monitoring of the progress of internal root resorption.

A virtual system for cavity preparation in endodontics.

This article presents a novel virtual teeth drilling system designed to aid dentists, dental students, and researchers in getting acquainted with teeth anatomy, the handling of drilling instruments, and the challenges associated with drilling procedures during endodontic therapy. The system is designed to be used for educational and research purposes in dental schools. The application features a 3D face and oral cavity model constructed using anatomical data that can be adapted to the characteristics of a specific patient using either facial photographs or 3D data. Animation of the models is also feasible. Virtual drilling using a Phantom Desktop (Sensable Technologies Inc., Woburn, MA) force feedback haptic device is performed within the oral cavity on 3D volumetric and surface models of teeth, obtained from serial cross sections of natural teeth. Final results and intermediate steps of the drilling procedure can be saved on a file for future use. The application has the potential to be a very promising educational and research tool that allows the user to practice virtual teeth drilling for endodontic cavity preparation or other related procedures on high-detail teeth models placed within an adaptable and animated 3D face and oral cavity model.

A new methodology for the comparative study of the root canal instrumentation techniques based on digital radiographic image processing and analysis.

OBJECTIVE: The objective of this study was to evaluate the utility of digital image processing and analysis procedures for the study and comparison of the efficiency of 2 root canal instrumentation techniques. STUDY DESIGN: Forty mandibular incisors with a single canal were randomly divided into 2 groups of 20 teeth. A step-back technique was followed for the instrumentation of the root canals of Group 1 teeth using hand stainless steel Hedström files (Dentsply Maillefer, Switzerland), while a crown-down technique using ProFile engine-driven nickel-titanium instruments (Dentsply Maillefer) was followed for the instrumentation of the Group 2 root canals. Radiographs of each tooth were taken in bucco-lingual and mesio-distal projections, both before and after instrumentation, under constant conditions and by using a direct digital intraoral radiography system. The postoperative radiographs were digitally subtracted from their respective preoperative radiographs. A contrast enhancement process was applied to the resultant digital subtractive images. The enlargement of the root canals created by each instrumentation technique regarding the apical 6 mm was assessed through the application of region segmentation and area measurement processes. RESULTS: Using this methodology no significant difference between the 2 preparation techniques was found in terms of configuration and enlargement of the root canals. CONCLUSIONS: The application of this methodology provided the ability to (1) visualize dentin lost during root canal instrumentation, (2) simultaneously compare root canal morphology before and after instrumentation, and (3) quantitatively evaluate the enlargement of the root canal area induced by each of the instrumentation techniques.

Digital radiograph registration and subtraction: a useful tool for the evaluation of the progress of chronic apical periodontitis.

The purpose of this study was to evaluate the suitability of a digital radiograph registration and subtraction software for a sensitive and reliable assessment of the progress of chronic apical periodontitis. Ninety cases of teeth with chronic apical periodontitis have been studied. In each case, a preoperative radiograph was taken, root canals were prepared, and a Ca(OH)2 paste was placed in the root canals. Radiographic control and replacement of Ca(OH)2 paste took place at 15-day intervals. The root canals were obturated 1.5 months after the first appointment. Recall radiographs were taken 0.5, 1.5, 3, 6, and 12 months after the obturation. All radiographs were taken for each case under constant conditions by using a direct digital radiography system. In each case, the preoperative, postoperative, and control and recall radiographs were digitally registered and pairwise subtracted. The resulting images were further processed by using contrast enhancement and pseudocoloring methods. Changes to the periapical tissue structure were easily detectable by using the above-mentioned methodology, even during short time intervals.

Virtual endodontics: three-dimensional tooth volume representations and their pulp cavity access.

The purpose of this study was the application of both digital three-dimensional image processing and virtual reality techniques in endodontics. Three-dimensional volume representations of 2 teeth from each tooth category, 16 teeth in total, have been reconstructed. All teeth were embedded in polyester resin, and serial cross-sections 0.75-mm thick were taken from each tooth by using a special microtome. Each section was studied under a stereoscopic microscope, and its microscopic image was directly digitized using a video-camera. The surfaces of hard dental tissues were segmented from each section. Semiautomatic alignment and frame interpolation were performed on the sequence of tooth sections by using appropriate digital image processing techniques. Three-dimensional volume representations from each tooth were achieved in this project to produce the final three-dimensional teeth models, on which virtual accesses of pulp cavities have been performed. Three-dimensional teeth volume representations and virtual tooth "drilling" could serve as perfect educational tools under certain circumstances.