Periapical Bone Lesions Research Articles

Clinical Approaches to the Three-Dimensional Endodontic Obturation Protocol for Teeth with Periapical Bone Lesions

Knowledge of dental anatomy and the three-dimensional principles of debridement, sterilization and obturation is necessary for effective root canal treatment. The chemo–mechanical preparation of the root canal biomechanically significantly reduces the number of microorganisms present. However, research has demonstrated that microorganisms frequently persist. The antimicrobial effect of the irrigants is essential to their biological function. Several obturation techniques are currently available, the selection of which depends on the canal’s morphology and the individual therapeutic goals of each instance. New sealing materials and methods for regenerative root canal obturation are enhancing and improving the predictability of three-dimensional (3D) sealing procedures. Epoxy sealers and gutta-percha are currently employed by clinicians as the gold standard in obturation procedures. The most recent developments in endodontic sealing materials are related to bioceramic sealers. Reports indicate that bioceramic sealers are biocompatible, harmless, hydrophilic, expandable and antibacterial. In the therapy of teeth with periapical lesions, not only the effective treatment of the root canal system but also the quality of the used sealer are of particular importance. Regenerative processes in the bone lesion are potentiated by the action of the sealer due to its highly biocompatible, non-toxic, aluminum-free and antibacterial capabilities. This paper discusses sophisticated root canal sealing materials and contemporary filling techniques in the regenerative therapy protocol for teeth with periapical bone lesions.

Effect of an Extremely Low-Frequency Electromagnetic Field on the Concentration of Salivary Immunoglobulin A.

Extremely Low-Frequency Electromagnetic Field (ELF MF) therapy is effective in the treatment of injury, inflammation and postoperative complications. Its clinical applications relate to bone unification, pain reduction, soft tissue oedema and the decrease of electric potentials in the oral cavity. It enhances regeneration of periapical bone lesions. It is obvious that cells (leukocytes, platelets, keratinocytes, osteoblasts) and proteins (fibrin, collagen, elastin and growth factors) exhibit alterations when exposed to an Extremely Low-Frequency Electromagnetic Field. The aim of the study was to evaluate the effect of an Extremely Low-Frequency Electromagnetic Field (ELF MF) on the parotid gland on the concentration of salivary immunoglobulin A. The study group consisted of 24 patients, aged 14–16, who underwent ELF MF on the parotid gland region. The control group comprised 25 matching persons. The IgA concentration in saliva samples was established using radial immunodiffusion. Following ELF MF, a statistically significant increase in the concentration of secretory immunoglobulin A was found in the study group, whereas in the control group, no statistically significant differences were noted. It can be concluded that an Extremely Low-Frequency Electromagnetic Field increases the activity of the immune system of the parotid gland.

In vitro assessment of periapical lesions created in sheep mandibles by using high resolution ultrasonography and cone beam computed tomography.

Providing ultrasound images of periapical lesions may be problematic depending on the thickness of the overlying cortical bone. Clinically, it is crucial to determine the cut-off value of overlaying bone thickness in terms of interference with ultrasound imaging in conjunction with assessment of changes in periapical jaw bone lesions. Our aim was to determine the minimum amount of overlaying buccal bone thickness of artificial periapical lesions in order to be visible by ultrasound imaging and to compare width, height, depth, surface area and volume measurements of detectable periapical lesions obtained from ultrasound and CBCT images. Periapical lesions were created in 16 molar teeth of sheep mandibles. Cavities were enlarged until the borders of lesions were visible on 14 MHz hockey probe ultrasound imaging. CBCT and ultrasound images were obtained simultaneously after drilling and enlarging each size of the cavities and replacing the teeth in their sockets. two observers separately assessed images twice within 2 weeks of interval. By using CBCT and ultrasound images, buccal bone thickness, maximum width, height, depth, surface area and volume of periapical lesions were measured. Intraclass correlation coefficient (ICC) was utilized and significance level was set at p < 0.05. The mean buccal bone thickness ranged between 1.21 mm and 1.31 mm for both imaging techniques. For the measurement of buccal bone thickness, periapical lesion width, height, depth, surface area, and volume excellent ICC values were found in terms of intrarater (ranging between 0.907 and 1) and inter-rater (ranging between 0.864 and 1) reliability for both observers and their readings. There were no statistically significant differences for both observers and for their two readings between ultrasound and CBCT measurements of buccal bone thickness, and periapical lesion width and height (p > 0.05). We suggested that a buccal thickness of approximately 1.28 mm might be accepted as a cut-off value for the detection of periapical lesions with 14 MHz hockey probe ultrasound. High resolution ultrasound provided accurate information for the measurement of buccal bone thickness and lesion width and height.

A Prospective Comparative Randomized Clinical Trial of Three Endodontic Retrograde Filling Materials

Background: A clinical trial was designed to evaluate bone regeneration in patients who received one of three retrosealants after apicoectomies in teeth with periapical lesions of endodontic origin to determine which is the best.Methods: Three retrosealants (EndoSequence, ProRoot MTA, Biodentine) were used following microsurgical apicoectomies in a prospective comparative randomized clinical trial in 74 patients who were selected from the endodontics department at the Universidad de Valparaiso, Chile. Clinical and CBCT evaluations were performed up to six months following the procedure.Results: There were no significant statistical differences in the bone regeneration among the three groups. The distribution of outcome was examined by the Kolmogorov-Smirnov test for normality. The Kruskal-Wallis test was used to examine differences among the three groups and pairwise comparisons were conducted by using Mann-Whitney tests.Conclusions: There were no significant differences in the healing of the periapical bone lesion between the three materials used in this investigation. Other studies with a larger number of cases and a longer follow-up time are recommended.Practical implications: Based on the results of this study, the clinician can choose any of the three retrofilling cements to seal the canals after an apicectomy.

Ultrasound examination for the detection of simulated periapical bone lesions in bovine mandibles: an ex vivo study.

To evaluate the accuracy of ultrasound examination (USE) for the detection of artificial bone defects in bovine mandibles in the absence of complete erosion of the cortical bone plate and to determine the minimum cortical thickness that constitutes a barrier for ultrasound waves. Sixty bovine mandibular anatomical blocks were harvested and uniformly distributed amongst six experimental groups. The negative control consisted of blocks with no intra-bony defects, whereas the positive control consisted of blocks with an artificial lesion of 2mm diameter that perforated the buccal cortical bone plate. Two experimental groups comprised blocks with small (2mm) and large (5mm) artificial defects created under a cortical plate thinned to varying thicknesses. Two additional groups had small (2mm) and large (5mm) artificial defects that did not involve the cortical plate. After USE, the scans were saved and submitted to three blinded examiners. Sensitivity, specificity, predictive values and receiver-operating characteristics (ROC) were analysed. The significance of the findings (P<0.05) was appraised using the chi-square statistics with the Yates correction, whilst the intra- and inter-examiner agreements were evaluated through Kappa statistics. USE was associated with high sensitivity (97.3%) and negative predictive value (89%), and a perfect score for specificity and positive predictive value. The ROC curve analysis revealed an accuracy of 97.8%. The k-values were 0.86 and 0.89 for the first and second examinations, respectively, demonstrating very high inter-observer agreement. The intra-observer agreement was also high (k-value=0.92). A significant correlation between the echographic diagnosis and the presence or absence of artificial intraosseous lesions in the anatomical blocks of bovine mandibles was observed (P<0.0001). USE was highly accurate and reliable for the detection of artificial lesions within bovine mandibles, regardless of the thickness or presence of the cortical plate.

Resolvin D2 Induces Resolution of Periapical Inflammation and Promotes Healing of Periapical Lesions in Rat Periapical Periodontitis.

Periapical periodontitis results from pulpal infection leading to pulpal necrosis and resorption of periapical bone. The current treatment is root canal therapy, which attempts to eliminate infection and necrotic tissue. But, in some cases periapical inflammation doesn't resolve even after treatment. Resolvins belongs to a large family of specialized pro-resolving lipid mediators that actively resolves inflammation signaling via specific receptors. Resolvin D2 (RvD2), a metabolite of docosahexaenoic acid (DHA), was tested as an intracanal medicament in rats in vivo. Mechanism was evaluated in rat primary dental pulp cells (DPCs) in vitro. The results demonstrate that RvD2 reduces inflammatory cell infiltrate, periapical lesion size, and fosters pulp like tissue regeneration and healing of periapical lesion. RvD2 enhanced expression of its receptor, GPR18, dentin matrix acidic phosphoprotein 1 (DMP1) and mineralization in vivo and in vitro. Moreover, RvD2 induces phosphorylation of Stat3 transcription factor in dental pulp cells. We conclude that intracanal treatment with RvD2 resolves inflammation and promoting calcification around root apex and healing of periapical bone lesions. The data suggest that RvD2 induces active resolution of inflammation with pulp-like tissue regeneration after root canal infection and thus maybe suitable for treating periapical lesions.

Accuracy of digital and film panoramic radiograph for assessment the sites of periapical bone lesions (comparative study )

The dental pulp is a delicate connective tissue , it react to bacterial infection or toother stimuli by an inflammatory response .Once infection has been established in thepulp , spread of the process can be through the root canals and into the periapicallesions.The aim of this study was to evaluate the accuracy of digital and film panoramicradiographs in detection the periapical bone lesion in different sites ,which detectedpreviously by periapical radiographs .In this study 106 teeth were examined by intraoral periapical radiographs which indicated that only 60 teeth were with periapicalbone lesion , then by both digital and film panoramic the teeth with periapical lesionwere examined .The results show significant advantage of digital panoramic whichshow the same mean of periapical lesion like conventional periapical radiographs ,also the study show significant differences between digital and film panoramicradiographs in incisor region for the detection of periapical bone lesion .

Sirtuin 1 regulates matrix metalloproteinase-13 expression induced by Porphyromonas endodontalis lipopolysaccharide via targeting nuclear factor–κB in osteoblasts

ABSTRACTPorphyromonas endodontalis lipopolysaccharide (P.e LPS) is an important initiating factor for periapical inflammation and bone destruction. Matrix metalloproteinase-13 (MMP-13) has been shown to participate in the formation and diffusion of periapical bone lesion in chronic apical periodontitis. Sirtuin 1 (SIRT1) is a key regulator of inflammation in mammalian cells which suppresses the release of inflammatory mediators. This study aimed to explore the role of SIRT1 in regulating MMP-13 expression induced by P.e LPS in osteoblasts. P.e LPS stimulated MMP-13 expression in MC3T3-E1 cells. Knockdown of SIRT1 reinforced the increase of MMP-13mRNA expression induced by P.e LPS. SIRT1 activator resveratrol significantly reduced the expression of MMP-13 and SIRT1 inhibitor EX-527 enhanced the expression of MMP-13. Moreover, SIRT1 activation with resveratrol inhibited acetylation of NF-κB p65 and NF-κB transcriptional activity, which were enhanced by P.e LPS. In addition, NF-κB p65 was involved in P.e LPS-induced MMP-13 expression via directly binding to the MMP-13 promoter. However, SIRT1 activation significantly interfered with this binding. These findings strongly suggest that P.e LPS induces MMP-13 expression in osteoblasts, and SIRT1 suppresses this expression of MMP-13 through targeting NF-κB p65. This provides new insights into understanding the actions of SIRT1 on anti-inflammatory and anti-bone resorption activity.

Periapical repair following endodontic surgery: two- and three-dimensional imaging evaluation methods.

This study quantitatively assessed the periapical bone repair following endodontic surgery, using planimetric evaluation based on two- (conventional and digital intraoral radiographic images - IRs) and three-dimensional (cone beam computed tomography - CBCT) evaluation. Eleven maxillary anterior teeth (of 11 patients) with periapical bone lesions and indication for surgical endodontic treatment were selected. IRs and CBCT images were acquired before the endodontic surgery, and 48 h, 4, and 8-months after the surgery. In each period of evaluation, the area (mm2) of the bone lesion was measured in the images, and the values for the three methods were compared. The area in the CBCT images was measured in the mesio-distal sections comprising the largest diameter of the lesion. Data were submitted to repeated measures 2-way ANOVA and t-tests with Bonferroni correction. There was significant difference between the periods of evaluation (p=0.002) regarding the assessed periapical bone lesion area. There was no statistically significant difference between the methods of evaluation (p=0.023). In the CBCT images the lesion areas were 10% larger than those observed in the conventional IRs (22.84 mm2) and 15% larger than those observed in the digital IRs (21.48 mm2). From the baseline (40.12 mm2) to 4 (20.06 mm2) and 8-months (9.40 mm2), reductions of 50 and 77% in the lesion area, respectively, were observed (p<0.0001). From 4 to 8-months, this value was 53%. Progressive bone repair could be seen from 48 h to 8-months following endodontic surgery based on two- (conventional and digital IRs) and three-dimensional (CBCT) evaluation. CBCT images provided results similar to those assessed by means of IRs.

Periapical and Endodontic Status Scale Based on Periapical Bone Lesions and Endodontic Treatment Quality Evaluation Using Cone-beam Computed Tomography

IntroductionThe purpose of this study was to present a new periapical and endodontic status scale (PESS) that is based on the complex periapical index (COPI), which was designed for the identification and classification of periapical bone lesions in cases of apical periodontitis, and the endodontically treated tooth index, which was designed for endodontic treatment quality evaluation by means of cone-beam computed tomographic (CBCT) analysis. MethodsPeriapical and endodontic status parameters were selected from the already known indexes and scientific literature for radiologic evaluation. Radiographic images (CBCT imaging, digital orthopantomography [DOR], and digital periapical radiography) from 55 patients were analyzed. All parameters were evaluated on CBCT, DOR, and digital periapical radiographic images by 2 external observers. The statistical analysis was performed with software SPSS version 19.0 (SPSS Inc, Chicago, IL). Chi-square tests were used to compare frequencies of qualitative variables. The level of significance was set at P ≤ .05. ResultsOverall intraobserver and interobserver agreements were very good and good, respectively. CBCT analysis found more lesions and lesions of bigger dimension (P < .001). CBCT imaging was also superior in locating lesions in the apical part on the side compared with DOR and in the diagnosis of cortical bone destruction compared with both methods (P < .001). Through CBCT analysis, more root canals and more canals associated with lesions were found. The most informative and reproducible periapical and endodontic status parameters were selected, and a new PESS was proposed. ConclusionsThe classification proposed in the present study seems to be reproducible and objective and adds helpful information with respect to the existing indexes. Future studies need to be conducted to validate PESS.

A comparative study on diagnostic accuracy of colour coded digital images, direct digital images and conventional radiographs for periapical lesions - an in vitro study.

The identification and radiographic interpretation of periapical bone lesions is important for accurate diagnosis and treatment. The present study was undertaken to study the feasibility and diagnostic accuracy of colour coded digital radiographs in terms of presence and size of lesion and to compare the diagnostic accuracy of colour coded digital images with direct digital images and conventional radiographs for assessing periapical lesions. Sixty human dry cadaver hemimandibles were obtained and periapical lesions were created in first and second premolar teeth at the junction of cancellous and cortical bone using a micromotor handpiece and carbide burs of sizes 2, 4 and 6. After each successive use of round burs, a conventional, RVG and colour coded image was taken for each specimen. All the images were evaluated by three observers. The diagnostic accuracy for each bur and image mode was calculated statistically. Our results showed good interobserver (kappa > 0.61) agreement for the different radiographic techniques and for the different bur sizes. Conventional Radiography outperformed Digital Radiography in diagnosing periapical lesions made with Size two bur. Both were equally diagnostic for lesions made with larger bur sizes. Colour coding method was least accurate among all the techniques. Conventional radiography traditionally forms the backbone in the diagnosis, treatment planning and follow-up of periapical lesions. Direct digital imaging is an efficient technique, in diagnostic sense. Colour coding of digital radiography was feasible but less accurate however, this imaging technique, like any other, needs to be studied continuously with the emphasis on safety of patients and diagnostic quality of images.

Detection and measurement of artificial periapical lesions by cone‐beam computed tomography

To test the ability of periapical radiography (PA) and cone-beam computed tomography (CBCT) to determine the presence/absence of periapical lesions and examine the reliability of volumetric measurements of periapical lesions on CBCT scans. After tooth extractions in human mandibles, bone defects were cut at the base of extraction sockets to mimic periapical bone lesions. The teeth were then returned into the extraction sockets. Sixty-three roots of anterior teeth, premolars and molars with artificial periapical lesions and 37 roots without lesions were examined with PA and CBCT. Presence/absence of periapical lesion was noted. The CBCT-based volume of each lesion (Vct) was measured using Amira software 5.4 (Visage Imaging GmbH, Berlin, Germany). A replica of each lesion was created using silicone impression material, and the volume of the replica was measured using a water displacement method, representing the physical volume of the lesion (Vp). Regression analysis was used to test the correlation between the Vp and Vct values. The positive and negative predictive values and accuracy for CBCT in diagnosing periapical lesions were all 1, compared with 1, 0.64 and 0.79 for PA diagnosis. Twenty-one (33%) lesions were undetected by PA. The Vp (21.5 ± 11.0 mm(3) ) and Vct (21.4 ± 11.5 mm(3) ) values of 63 lesions were highly correlated (R(2) = 96.9%, P < 0.001). Cone-beam computed tomography is more accurate than PA in diagnosing periapical lesions associated with mandibular teeth. The volumes of artificial mandibular periapical lesions were accurately measured with CBCT data.

Comparison of cone beam CT device and field of view for the detection of simulated periapical bone lesions

We aimed to assess the diagnostic accuracy of different cone beam CTs (CBCTs) and the influence of field of view (FOV) in diagnosing simulated periapical lesions. 6 formalin-fixed lateral mandibular specimens from pigs were used for creating 20 standardized periapical bone defects. 18 roots were selected for the control group. Three CBCT devices [Accuitomo 3D® (Morita, Kyoto, Japan), NewTom 3G (Quantitative Radiology, Verona, Italy) and Scanora® (Soredex, Tuusula, Finland)] and three FOVs (NewTom 3G® FOV 6, 9 and 12 inches) were used to scan the mandible. Five observers assessed the images, using a five-point probability scale for the presence of lesions. Specificity, sensitivity and areas under the receiver operating characteristic (ROC) curves were calculated. Sensitivity ranged from 72% to 80%. Specificity ranged from 60% to 77%. A difference in scoring between Scanora and the other two devices existed only in the control group. ROC analysis for different FOVs showed a decreased sensitivity with an increasing FOV, but this difference was not significant. the control group, there was a difference between the CBCT devices regarding their specificity. FOV size did not show any difference in diagnostic performance. In cases in which conventional radiographic methods in combination with clinical evaluation are not sufficient, CBCT may be the method of choice to assess periapical pathology. CBCT examinations should be complementary to a clinical examination and FOV adaptation can be utilized to keep the dose to the patient as low as possible.

Radiological diagnosis of periapical bone tissue lesions in endodontics: a systematic review

This systematic review evaluates the diagnostic accuracy of radiographic methods employed to indicate presence/absence and changes over time of periapical bone lesions. Also investigated were the leads radiographic images may give about the nature of the process and the condition of the pulp in nonendodontically treated teeth. Electronic literature search included the databases PubMed, Embase and CENTRAL from January 1950 to June 2011. All languages were accepted provided there was an abstract in English. The MeSH terms were 'Cone beam computed tomography (CBCT)', 'Radiography, panoramic', 'Periapical diseases', 'Dental pulp diseases', 'Sensitivity and specificity', 'receiver operating characteristics (ROC) curve', 'Cadaver', 'Endodontics' and 'Radiography dental'. Two reviewers independently assessed abstracts and full text articles. An article was read in full text if at least one of the two reviewers considered an abstract to be potentially relevant. Altogether, 181 articles were read in full text. The GRADE approach was used to assess the quality of evidence of each radiographic method based on studies of high or moderate quality. Twenty-six studies fulfilled criteria set for inclusion. None was of high quality; 11 were of moderate quality. There is insufficient evidence that the digital intraoral radiographic technique is diagnostically as accurate as the conventional film technique. The same applies to CBCT. No conclusions can be drawn regarding the accuracy of radiological examination in identifying various forms of periapical bone tissue changes or about the pulpal condition.

A suggested technique for the application of the cone beam computed tomography periapical index

Cone beam CT (CBCT) produces undistorted three-dimensional (3D) images of the maxillofacial region with a radiation dosage lower than conventional CT. The periapical index score (PAI) is commonly used to follow up the lesions in the bone using periapical radiographs. Recently, a new PAI based on CBCT was introduced (CBCT-PAI). The aim of this technical report is to present a modified reproducible method to assess the CBCT-PAI. CBCT was used to evaluate a periapical bone lesion observed in the area of tooth number 13 before treatment and 2 years after treatment. The modified CBCT-PAI was applied to both the examinations to measure the lesion. The dimensional analysis of the lesion was performed in each plane, assessing three fixed and reproducible dimensions: mesiodistal (M-D), buccolingual (B-L) and coronoapical (C-A). The images were evaluated by three mutually independent examiners. Data were collected and reported in a chart. The results were compared with each other and with the PAI score from the periapical radiographs. The three observers reported the same measurements of the lesion for each plane. The CBCT-PAI follow-up showed a reduction of the size of the lesion (5D vs 4D) but also an increase in the erosion of the buccal cortical plate. The comparison of CBCT-PAI with classic PAI showed the first method to be more precise. This technical report shows how the CBCT-PAI can be applied to the CBCT exam of a periapical lesion in a reproducible way.

A prospective cohort study of endodontic treatments of 1,369 root canals: results after 5 years

The purpose of this prospective study was: 1) to follow-up a large number of endodontic treatments performed by a single operator, periodically checked over a 5-year period; and 2) to correlate outcome to a number of clinical variables. This prospective study included all consecutive cases during the selected time period. All cases were followed regularly for a 5-year period. At the 5-year end point of the study, 470 patients with 816 treated teeth and with 1,369 treated root canals were available for evaluation. The overall rate of success among the 816 teeth/1,369 root canals available for evaluation was 88.6%/90.3%. The success rate for 435 teeth/793 root canals undergoing vital pulp therapy was 91.5%/93.1%. Teeth/root canals with necrotic pulp but without detectable periapical bone lesion were successfully treated in 89.5%/92.3%. If the pulp necrosis was complicated by apical periodontitis, the success rate fell to 82.7% for the teeth and 84.1% for the root canals (P = .037). Teeth with periapical lesion <5 mm had a success rate of 86.6%, and in cases where the lesion was ≥ 5 mm the rate of success was 78.2%. More severe disease conditions negatively affects outcome. An optimal working length was identified. Excess of root canal filling material decreases success. Infected pulp space should be treated with an effective intracanal dressing. The quality of the coronal restoration or the placement of intracanal post retentions does not affect treatment outcome.

Treatment of through-and-through bone lesion using autologous growth factors and xenogeneic bone graft: a case report

This pilot case study aimed at evaluating the possibility of achieving optimal hard and soft tissue regeneration using plasma rich in growth factors (PRGF) and anorganic bovine bone (ABB) for the surgical treatment of a large through-and-through periapical bone lesion. Maxillary incisors of a patient with through-and-through periapical lesion of endodontic origin were treated using modern endodontic surgical technique with the adjunct of PRGF. The PRGF clot was positioned over the palatal side of the lesion while the remaining bone defect was grafted with PRGF and ABB. A collagen membrane embedded with plasma very rich in growth factors covered the graft. Post-operative pain and swelling were negligible, and soft tissue healing was very fast. One-year clinical and radiographic outcome showed complete healing and functionality. The addition of PRGF to ABB could improve the regenerative process, reducing postoperative symptoms and resulting in a fast and predictable hard and soft tissue healing.

Influence of bony defects on implant stability

The purpose of this study was to analyze the evolution of implant mechanical stability in different types/sizes of bony defects using both Periotest and Osstell devices as "objective tools." Thirty-two implants were randomly allocated to one of the four types of bone defects: marginal bone loss, peri-apical bone defect, constant width dehiscence and constant length dehiscences. Periotest/Osstell measurements were completed before and during staged bone removal (to enlarge defect size). Significant differences (P<0.05) with initial values were found after a 2 mm marginal bone removal (Osstell/Periotest); for a peri-apical bone lesion, after removal of 5 mm (Osstell) or 8 mm (Periotest); for a 6-mm-long dehiscence, after removal up to 180 degrees of the implant perimeter (Osstell/Periotest); for a 3-mm-wide dehiscence, after removal of 10 mm (Osstell) or 6 mm (Periotest). Periotest and Osstell are in general not very sensitive in the identification of peri-implant bone destruction, except for marginal bone loss.

Development of Virtual Simulation Platform for Investigation of the Radiographic Features of Periapical Bone Lesion

Introduction The periapical radiograph is used as an important tool in the assessment of periapical bone lesions in endodontic therapy. The purpose of this study was to develop a virtual simulation platform for radiographic research of periapical bone lesions based on a digitally reconstructed radiograph and to investigate the radiographic features of different simulated periapical bone lesions. Methods A cadaver mandible was scanned by microcomputed tomography. The application framework for the creation of a digitally reconstructed radiograph with virtual periapical lesions was constructed. Subsequently, different size and shape periapical lesions were created virtually in an incisor, a premolar, and a molar, and the digitally reconstructed radiographs were produced. Result The detection of periapical lesions based on digitally reconstructed radiographs was depended on lesion size, position, shape, and tooth position. Virtual periapical lesions could not be visualized with lesions smaller than 1 mm in the incisor, 2 mm in the premolar, and 3 mm in the molar, and these virtual lesions were confined within the cancellous bone. A 4-mm lesion in the molar was still not visualized even if it encroached on the cortical bone. If the lesions encroached on the junctional trabeculae and cortical bone or the lesion was created with the maximal buccal-lingual dimension in ellipsoid shape and confined within the cancellous bone giving it an abnormal shape, it could be seen, except for the “thinnest” 1-mm lesion in incisor region. Conclusions The virtual simulation platform described here provides a reproducible assessment of periapical lesions and aids in a better understanding of the characteristics of periapical lesions.

Radiovisiography and ultrasound real time imaging in the differential diagnosis of periapical lesions of endodontic origin - A comparative in vivo study

Background & Objective: Radiographic images are routinely used in the field of endodontics for the diagnosis, treatment planning and follow-up of periapical bone lesions. The possibility of making a distinction between cystic lesions and granulomas among the lesions of endodontic origin may be important in the management of periapical pathosis and in predicting endodontic treatment. Recent developments in radiovisiography (RVG) and Ultrasonography have given the dentist the ability to perform radiographic examinations with greatly reduced rates of radiation exposure. Objective of the study is to assess whether the use of real time ultrasound imaging and RVG can help in the differential diagnosis of periapical lesions of endodontic origin. Method: Ten patients diagnosed with periapical lesions using conventional radiographic findings were subjected to radiovisiography and ultrasound imaging. The comparative evaluation of reports of radiologist and echographist was done to arrive at a tentative differential diagnosis. Interpretation and conclusion: This study has shown that there was definite correlation between the echo structure of a lesion and the nature of lesion. Cystic lesion versus granuloma. The results obtained tallied 90% of the time. Based on the results we can conclude that real time ultrasound imaging and RVG can be used in the endodontic field for the study of periapical lesions.