Digital Subtraction Radiography Research Articles

Digital Subtraction Radiography in Dentistry: An Overview

Digital imaging has transformed the field of medical and dental imaging by overcoming many of the drawbacks ofconventional film-based radiographs. These alterations, however, are hidden behind a background of typical anatomical featuresand are not readily visible, making it difficult for the human eye to discern them. One image-enhancing method or tool that solvesthis issue is digital subtraction radiography, which has recently found usage in a number of dental specialties. Quantitative measuresfrom digital subtraction pictures have been validated as a result of the development of digital imaging technology. Moreover,changes made to computer software have made the clinical use of subtraction imaging more adaptable. Digital subtraction radiologyhas significantly improved the ability to find oral and maxillofacial lesions. Comparing standardised radiographs acquired duringsuccessive examination sessions is done using digital subtraction radiography. Any structures that have not changed are removed,and these regions are shown in the subtraction picture as neutral grey areas, whilst parts that have altered are shown as deeperor brighter shades of grey. Yet, there is not much analysis of this often used method in the literature. The purpose of this articleis to examine this technology, its applications in different areas of dentistry, and its potential for detecting a range of disorders.This review article highlights its basic principles, applications, technique, advantages, disadvantages and future scope of digitalsubtraction radiography in dentistry.

Metformin gel in the treatment of generalized aggressive periodontitis

ObjectivesThe aim of this study was to assess the adjunctive regenerative effect of metformin (MF) gel in the treatment of stage II grade C periodontitis utilizing β-TCP bone graft in the control group, and β-TCP bone graft mixed with 1% MF gel in the test group on clinical, radiographic, and biochemical parameters.Patients and methodsThirty intrabony defects were selected in seven patients who met the inclusion criteria. Patients were randomly distributed in the two study groups and treated with β-TCP bone graft plus collagen membrane in the control group and β-TCP bone graft mixed with 1% MF gel plus collagen membrane in the test group. Clinically, evaluation was carried out by clinical parameters (bleeding on probing, pocket depth, and clinical attachment loss) at 3, 6, and 9 months posttreatment. Biochemically, gingival crevicular fluid concentration of receptor activator of nuclear factor-κB ligand (RANKL) and Osteoprotegerin (OPG) at baseline and 9 months posttreatment were evaluated and RANKL/OPG ratio was calculated. Radiographically, quantitative digital subtraction radiography was used to evaluate bone gain and bone mineral density at 9 months posttreatment follow up period.ResultsThe intragroup comparison in the two studied groups demonstrated statistically significant improvement in all clinical parameters (bleeding on probing, pocket depth, and clinical attachment loss) after 3, 6, and 9 months when they were compared to their corresponding values at baseline, while, the intergroup comparison showed that there is no statistically significant difference regarding all clinical parameters at 3, 6, and 9 months posttreatment except pocket depth which differs statistically significant at 3 months posttreatment. The intragroup comparison of RANKL and OPG was statistically significant between baseline and 9 months posttreatment in the two groups but intergroup comparison revealed that there is no statistically significant difference. Regarding RANKL/OPG ratio, the intragroup analysis revealed that there was a statistically significant change in this ratio from baseline to 9 months posttreatment in the test and control group. Additionally, the intergroup analysis revealed that there was no statistically significant difference in RANKL/OPG ratio between the test and control group at baseline and at 9 month posttreatment. The intragroup quantitative digital subtraction radiography analysis demonstrated statistically significant bone gain and increase in bone mineral density in the two studied groups. Also, the intergroup comparison revealed that no statistically significant increase in bone level in the two groups although increase in bone density was statistically significant.ConclusionThe present study demonstrated that guided tissue regeneration utilizing 1% MF gel combined with β-TCP bone graft showed better radiographic results, when compared with guided tissue regeneration utilizing β-TCP bone graft alone. The adjunctive regenerative action of MF is promising material for periodontal regeneration.

Clinical and Radiographic Evaluation of Applying Atorvastatin 1.2% Bio Adhesive with Plasma Rich in Growth Factor (PRGF) for Treatment of Mandibular Class II Furcation Defects: a Randomized Clinical Trial.

Statement of the Problem: Molar teeth with furcation involvement are one of the most common problems in patients with periodontal disease. Regeneration methods are of the most controversial treatment strategies for these lesions.Purpose: The purpose of this study was to determine the effect of plasma rich in growth factors (PRGF) with 1.2% Atorvastatin (ATV) in the treatment of furcation involvement of mandibular molars.Materials and Method: The present randomized clinical trial was conducted on 15 patients with moderate periodontitis and class II furcation involvements; 24 defects were located in four groups of six, including debridement, ATV1.2%, PRGF, PRGF with ATV1.2%. The parameters of vertical probing depth (VPD), vertical clinical attachment level (VCAL), gingival index (GI), horizontal probing depth (HPD) and gingival recession (GR) were measured at baseline (T0), immediately before surgery (T1), 3 (T2), and 6 (T3) months after surgery. Moreover, the bone conditions were evaluated by digital subtraction radiography before and six months after surgery. Data were analyzed using SPSS23 software.Results: No significant difference in radiographic parameters was observed among the groups (p= 0.08). There was no significant difference in the mean levels of VPD, VCAL and HPD among the groups at different times (p<0.05). Comparison of clinical parameters of VPD, VCAL and GI in the treatment groups compared to the baseline showed a significant improvement in each group (p< 0.05) but there was no significant difference among different groups (p< 0.05).Conclusion: The use of PRGF with ATV 1.2% in grade II furcation involvement in mandi-bular molars was effective in the improvement of clinical and radiographic parameters six months after treatment, but this effect revealed no difference in comparison with the other groups.

Long-term observation of periodontal condition following placement of removable partial dentures with rigid retainers and major connector in patients with/without diabetes: A retrospective study.

This retrospective study evaluated the periodontal tissues of the abutment teeth of removable partial dentures (RPDs) with rigid retainers and major connectors in patients with and without type 2 diabetes mellitus (T2D). A total of 313 patients who had been treated with RPDs, including rigid retainers and major connectors, were divided into two groups: T2D and non-T2D. The periodontal parameters and radiographic bone heights of the abutment teeth were evaluated at baseline and at a 5-year examination during supportive periodontal therapy (SPT). For patients with accessible standardized radiographs, bone density was analyzed based on the gray level (GL) using digital subtraction radiography (n = 83). Overall, 739 abutment teeth (86 in the T2D group) of 235 patients (25 in the T2D group) were analyzed, and 95.0% (94.2% in the T2D group, and 95.2% in the non-T2D group) were maintained. The mean probing pocket depth significantly increased in both groups (p < 0.001). There were significant changes in the radiographic bone height (p = 0.038) and GL on the side of the denture base area (p = 0.048) in the T2D group compared to those in the non-T2D group. Regardless of T2D, RPDs with rigid retainers and major connectors could prevent the progression of periodontal disease and successfully maintain most of the abutment teeth during 5-years of SPT. However, T2D may be significantly associated with loss of bone height reduction and density on the side of the denture base area.

Periodontal Ligament Cell Sheets and RGD-Modified Chitosan Improved Regeneration in the Horizontal Periodontal Defect Model.

Objective The aim of this study was to examine the potential of periodontal ligament (PDL) cells sheet and arginine-glycyl-aspartic acid (RGD)-modified chitosan scaffold for periodontal tissue regeneration in horizontal periodontal defect model. Materials and Methods PDL cell cytotoxicity was tested with 3–[4,5- dimethylthiazol-2yl]–2,5-diphenyl-2H-tetrazolium bromide assay. Cell migration toward the chitosan-based materials was analyzed with trans-well migration assay. Horizontal periodontal defect model was created in four maxillary and mandibular lateral incisors of Macaque nemestrina . Following periodontal therapy, the sites were transplanted with various regenerative materials: (1) chitosan, (2) RGD-modified chitosan, (3) PDL cell sheet with chitosan, (4) PDL cell sheet with RGD-modified chitosan. The periodontal tissue regeneration was evaluated clinically and radiographically. Gingival crevicular fluids were collected each week to evaluate cementum protein-1 (CEMP-1) expression with enzyme-linked immunosorbent assay, while the biopsies were retrieved after 4 weeks for histological and microcomputed tomography evaluation. Statistical Analysis Data was statistically analyzed using GraphPad Prism 6 for MacOS X. Normality was tested using the Shapiro–Wilk normality test. The Kruskal–Wallis test was used to compare the groups. Significance was accepted when p < 0.05. Results Clinical examination revealed more epithelial attachment was formed in the group with PDL cell sheet with RGD-modified chitosan. Similarly, digital subtraction radiography analysis showed higher gray scale, an indication of higher alveolar bone density surrounded the transplanted area, as well as higher CEMP-1 protein expression in this group. The incorporation of RGD peptide to chitosan scaffold in the group with or without PDL cells sheet reduced the distance of cement–enamel junction to the alveolar bone crest; hence, more periodontal tissue formed. Conclusions Horizontal periodontal defect model could be successfully created in M. nemestrina model. Combination of PDL cell sheet and RGD-modified chitosan resulted in the higher potential for periodontal tissue regeneration. The results of this study highlight the PDL cell sheet and RGD-modified chitosan as a promising approach for future clinical use in periodontal regeneration.

Reproducibility of subtraction radiography in monitoring changes in approximal carious lesions in children: An in vivo study.

Laboratory studies have shown that digital subtraction radiography (DSR) can be a more effective tool, than conventional radiography, in monitoring changes in carious lesions. The clinical performance of the technique, however, has not been sufficiently researched. To compare the reproducibility of DSR to that of bitewing radiographs, in monitoring changes in approximal caries in the mixed dentition. A secondary aim was to determine whether assessment outcomes differed as a function of the method used. Six assessors evaluated 310 lesions first on bitewings, then with DSR. The overall reproducibility was evaluated via intra-class correlation coefficient (ICC). Intra- and inter-rater reproducibility were assessed using weighted Kappa. Paired t test was used to assess differences in the reproducibility across methods. The overall reproducibility for DSR was (ICC=0.47, 95% CI=0.31-0.56). Intra- and inter-rater reproducibility were 0.65 and 0.44, respectively. The overall reproducibility for bitewings was ICC=0.45, 95% CI=0.42-0.57. Intra- and Inter-rater reproducibility were 0.71 and 0.46, respectively. Differences in the reproducibility across methods were not statistically significant. Significantly more lesions were scored as progressed using DSR. The reproducibility of DSR in monitoring changes in approximal caries is comparable to that of bitewings. Additionally, DSR detected higher proportion of progression than bitewing assessments.

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

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. 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. 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. 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. DSR is a cost- and time-effective imaging technique that could contribute in early diagnosis of VRFs.

4:12 PM Abstract No. 335 Safety and feasibility of transradial uterine fibroid embolization in an office-based lab

To assess the safety and feasibility of performing transradial uterine fibroid embolization (trUFE) in an office-based lab (OBL). A retrospective review was performed of all patients who underwent transradial uterine fibroid embolization (trUFE) at two office-based labs between June 2018 and July 2019. Data collected included demographic information, pertinent medical history, and procedural details (radiation exposure, length of procedure, time to discharge, complications). All procedures were performed under conscious sedation. Fluoroscopy and digital subtraction radiography were performed utilizing a portable C-arm (Philips Veradius). Ultrasound guidance for radial access was used in all cases. Bilateral Embolization was performed in all cases using embozene 500um and 700 μm particles. Approximately 8 mL of 1% lidocaine was administered to each uterine artery at the end of embolization. Postprocedural pain regimen consisted of fentanyl 25 mcg PRN and oxycodone/acetaminophen 5 mg/325 mg PRN. A total of 9 premenopausal women (mean age, 46.7 ± 4.9 years) underwent trUFE for symptomatic uterine fibroids. The mean procedure time was 68 minutes (range, 53-120) with the average fluoroscopy time of 22.1 minutes (range, 14.2-29.5). The average time to discharge was 4.4 hours. Median follow-up was 4 months. Clinical success measured by subjective relief in symptoms at 2-month follow-up was seen in 9/9 (100%) of the patients. There were no immediate or delayed postprocedural complications. One patient returned to the Emergency room 5 hours after discharge for pain management. Transradial uterine fibroid embolization can be safely performed in an office-based lab.

Seven-year-efficacy of proximal caries infiltration – Randomized clinical trial

ObjectivesWe report efficacy of resin infiltration to arrest progression of caries lesions as compared with non-invasive measures and oral hygiene education alone after a mean observation time of seven years. Materials and methodsThis randomized split-mouth placebo-controlled clinical trial included 22 young adults having 29 pairs of interproximal non-cavitated caries lesions with radiographic extensions into inner half of enamel (E2) or outer third of dentin (D1). Lesion pairs were randomly allocated to two treatment groups: infiltration (Icon, pre-product; DMG) or mock (control) treatment. All subjects received risk-related instructions for diet, flossing and fluoridation. The primary outcome was radiographic (digital subtraction radiography) lesion progression after seven years. Secondly, Kaplan-Meier-analyses were applied to analyze time-to-failure additionally including patients followed up for less than 54 months as well. ResultsTwo lesion pairs were excluded due to invasive treatment decision by another dentist, five lesion pairs were lost to follow-up prior to 54 months but included in the survival analysis. No unwanted effects could be observed. For the primary outcome in 17 patients followed up in mean for 84 months 2/22 infiltrated lesions (9 %) compared with 10/22 control lesions (45 %) progressed (p = 0.018). The relative risk reduction for test in relation to control was 80 % (CI 95 % = 19–95 %). For the survival analysis within a mean (SD) observation time of 73 (25) months mean failure rates of 1.3 % and 7.8 % could be observed for test and controls, respectively. Hazard risk (95 % CI) for caries progression was 6.6 (2–22) for the control compared with the test lesions (p = 0.002). ConclusionsWe conclude that resin infiltration of proximal caries lesions extending radiographically around the enamel dentin junction is efficacious to reduce lesion progression after a mean observation time of seven years. Clinical significanceThis randomized clinical trial proves that caries infiltration is highly efficacious compared with non-invasive measures and oral hygiene education alone after a considerably longer observation time of 7 years than studied so far before.

The Effect of Resin Infiltration on the Progression of Proximal Caries Lesions: A Randomized Clinical Trial

Objective: The aim of this clinical trial was to assess the effect of resin infiltration on the progression of proximal caries lesions. Subjects and Methods: Forty-one patients, aged between 15 and 33 years, with 2 or more non-cavitated proximal caries lesions were included. In 41 of the adolescent and young adults, 45 pairs of proximal lesions with radiological extension into the inner and outer half of the enamel, or into the outer third of the dentin, were randomly allocated to the test groups (resin infiltration application + fluoridated toothpaste and flossing use) or to the control group (fluoridated toothpaste and flossing use). Standardized geometrically aligned digital bitewing radiographs were obtained using individual biting holders. The radiographic progression of the lesions was assessed after 1 year by digital-subtraction radiography. The McNemar test was used for statistical analysis. Results: In the test group 1/45 of the lesions (2.2%) and in the control group 9/45 of the lesions (20%) showed progression. The caries progression rate of the control group was significantly higher than that of the test group (p < 0.05). Conclusions: Resin infiltration of proximal caries lesions is effective in reducing progression of the lesion.

Effects of topical application of 1% sodium alendronate gel in the surgical treatment of periodontal intrabony defects: A 6-month randomized controlled clinical trial.

Sodium alendronate (ALN) is an aminobisphosphonate and potent inhibitor of bone resorption. It has been suggested that ALN might be a promising carrier of biomolecules for periodontal bone repair. The aim of this randomized split-mouth clinical trial was to evaluate the effects of the topical application of 1% ALN gel in intrabony defects during the surgical treatment of patients with periodontitis. Sixty-four intrabony defects from 32 patients with periodontitis were randomly treated with either 1% ALN gel or placebo gel during periodontal surgeries. Full-mouth periodontal examination was performed at baseline and at 3 and 6 months after surgical treatment. Clinical attachment level (CAL), probing depth (PD), and bleeding on probing (BOP) were recorded as the clinical outcomes. Bone defects were evaluated by digital subtraction radiography (DSR) at baseline and 6 months post-treatment. Analyses were performed through Fisher, Kruskal-Wallis, and ANOVA tests and a generalized estimation equations method. Both ALN and placebo groups showed significant improvements in BOP, PD, and CAL after periodontal surgical procedures (P<0.001). Intergroup analysis showed significantly better outcomes in the ALN group with higher PD reduction and clinical attachment gain. DSR showed positive effects on periodontal bone repair strongly associated in the ALN group (P<0.001). Topical application of 1% ALN may be a promising and beneficial adjuvant for the treatment of intrabony defects during surgical periodontal therapy.

Clinical and radiographic evaluation of applying 1% metformin biofilm with plasma rich in growth factor (PRGF) for treatment of two-wall intrabony periodontal defects: A randomized clinical trial.

Background. The ultimate aim of periodontal treatment is to regenerate periodontium and regenerative treatment after that. The aim of this study was to evaluate the effect of PRGF with 1% metformin biofilm in the treatment of two-wall intrabony periodontal defects. Methods. In this clinical trial, 8 patients with moderate chronic periodontitis and two-wall intrabony defect were selected. The defects were assigned to 4 groups: debridement, 1% metformin, PRGF, PRGF and metformin. The parameters of vertical probing depth, vertical clinical attachment level and gingival index were measured at baseline, immediately before surgery, and 3 and 6 months after surgery. In addition, the radiographic changes were evaluated with digital subtraction radiography before and 6 months after surgery. Analysis of the results was performed with repeated measurements, Friedman test and chisquared test. Results. All the groups exhibited improvements in all the clinical parameters after 6 months. Inter-group comparison of GI, CAL and PPD parameters revealed no statistically significant differences. Radiographic changes in the group of 1% metformin with PRGF revealed statistically significant differences compared with other groups; however, there were no statistically significant differences in other groups. Conclusion. Application of PRGF with 1% metformin in intrabony two-wall periodontal defects was effective in improving the clinical parameters but this effect revealed no difference compared with other groups; however, in terms of radiographic changes significant improvements were noted

Treatment of intrabony defects with modified perforated membranes in aggressive periodontitis: subtraction radiography outcomes, prognostic variables, and patient morbidity

ObjectivesThe main objectives of this study were (1) to evaluate bone/graft density alterations by digital subtraction radiography; (2) to determine factors associated with favorable clinical and radiographic outcomes, and (3) to report on patient morbidity after guided tissue regeneration (GTR) in aggressive periodontitis (AgP) patients.Materials and methodsAdapting a split-mouth design, 30 comparative intrabony defects in 15 patients were randomly treated with xenogenic graft plus modified perforated membranes (MPM, tests) or xenogenic graft plus standard collagen membranes (CM, controls). The time period of observation was 12 months.ResultsThere were significant improvements in clinical and radiographic parameters within each group, without intergroup differences. However, higher PPD reduction for three-wall defects was noted in MPM sites (5.22 versus 3.62 mm; p = 0.033). Moreover, a significant gain in bone/graft density of 4.9% from 6 to 12 months post-operatively was observed in test sites. Multivariate analysis demonstrated that morphology of intrabony defects was a predictor of CAL gain (p = 0.06), while independent prognostic variables effecting changes in bone/graft density were radiographic defect depth (p = 0.025) and radiographic angle (p = 0.033). The majority of patients reported some discomfort, pain, and edema with mild intensity without any significant differences between treatment modalities.ConclusionsThis study demonstrated enhanced bone/graft density gain after GTR with MPM, which may indicate greater area of new bone formation. Independent variables effecting treatment outcomes were intrabony defect morphology, radiographic defect depth, and radiographic angle.Clinical relevanceThis study supports the regenerative treatment of intrabony defects in AgP patients and identifies some variables with prognostic value.

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.

Markers in blood and saliva for prediction of orthodontically induced inflammatory root resorption: a retrospective case controlled-study

BackgroundHormonal and enzymatic factors may render certain individuals more susceptible to orthodontically induced inflammatory root resorption (OIIRR). The objectives of this study are (1) to identify biochemical key markers in blood and saliva that may be correlated to the trend of extensive OIIRR and (2) to utilise these markers to predict a susceptible patient-receiving orthodontic treatment.MethodsNine patients (mean age 23 + 2.9 years) who had moderate to severe OIIRR that assessed via orthopantomograms and met the inclusion criteria were classified as the root resorption group (RRG). Blood chemistry was evaluated using the collection of fasting blood and unstimulated saliva samples. Multiplex enzyme-linked immunosorbent assay (ELISA) arrays were used to screen blood and saliva samples for human cytokines, chemokines and several key enzymes that may play a role in root resorption following orthodontic force application. Biochemical findings from 16 matching subjects were used as the control (CG) for comparative measurements.ResultsPatients with moderate to severe OIIRR showed a significant increase in salivary cytokines including interleukin (IL) 7, IL-10, IL-12p70 and interferon-gamma (IFN-γ) level as well as a significant decrease in IL-4 level. Osteocalcin and procollagen type I N-terminal peptide (P1NP) appeared to be the only blood factors that showed a significant difference, more in the CG than the RRG.ConclusionsSaliva might be a more valuable way of measuring changes in cytokine expression than blood secondary to orthodontic treatment. Although the increased expression of pro-inflammatory and anti-inflammatory cytokines may be determinants in the development of moderate to severe OIIRR, cytokine expression may be affected by several potential inflammations in another part of the body. Future research could investigate the cause/effect relationship of different cytokines, in a larger group of patients and at different time intervals, using digital subtraction radiography techniques and microfluidic biosensors.

Clinical performance of self-assembling peptide P11 -4 in the treatment of initial proximal carious lesions: A practice-based case series.

The aim of the present study was to investigate the clinical performance of self-assembling peptide P11 -4 on non-cavitated initial proximal carious lesions 12months after treatment. Twenty-six patients, aged between 18 and 65years, with 35 carious lesions were included in this practice-based, uncontrolled, prospective case series. The opacity and size of the proximal lesions were evaluated visually at baseline and at day 360 using standardized single-tooth or bite-wing and digital-subtraction radiography. Pairwise evaluation of images was carried out in a randomized and blinded manner with respect to the time point. Twelve months after treatment of the proximal carious lesions, the visual evaluation showed a predominant shift toward regression of the initial lesions. Radiographic assessment yielded regression of the caries in 17 of 28 cases; four of 28 were regarded as unchanged, and seven of 28 lesions showed progression of the carious lesion. Combined assessment of clinical radiographs and digital subtraction radiographs confirmed the radiographic assessment, with 20 of 28 lesions showing total or partial regression, four unchanged, and four progressing. Radiographic and digital subtraction analyses suggest that initial proximal carious lesions can regress after treatment with P11 -4, but additional factors might influence the overall treatment outcome.

Chronological grey scale changes in supporting alveolar bone by removable partial denture placement on patients with periodontal disease: A 6-month follow-up study using digital subtraction analysis

ObjectivesThe purpose was to assess the early effects of removable partial denture (RPD) placement on abutment teeth in patients with periodontal disease. MethodsFifteen distal-extension RPDs and 19 abutment teeth were evaluated in 13 patients with moderate-to-severe periodontal diseases. Clinical periodontal records and grey level (GL) score based on digital subtraction radiography were measured on the day of denture placement (baseline) and at 1day, 1 week, 1 month, 3 months, and 6 months after the placement. Occlusal force on total dentition (Ft) and abutment tooth (Fa) were recorded with (baseline) and without denture on the day of the placement, and with denture in the follow-up examinations. ResultsNo statistically significant difference between a follow-up period and the baseline was found in the clinical periodontal and occlusal force records, except for Ft with denture on the day of the placement, which was significantly lower than the baseline (p<0.05). The GL at distal crestal of the abutment was significantly higher at 1 week after the placement than at the baseline (p<0.05), while the scores of following examinations returned to the baseline level. ConclusionsThe distal crestal bone of the abutment tooth transitorily reacts to mechanical stress due to the denture placement, while this does not suggest a detrimental effect within the limitation of the study design with a short-term observation period. Clinical significanceThe RPDs can be safely used for patients with periodontal diseases for at least 6 months if they are properly placed and maintained by professional care.

Apical Transportation, Centering Ratio, and Volume Increase after Manual, Rotary, and Reciprocating Instrumentation in Curved Root Canals: Analysis by Micro-computed Tomographic and Digital Subtraction Radiography

IntroductionThis study aimed to evaluate apical transportation (AT), centering ratio (CR), and volume increase (VI) produced after instrumentation of mesiobuccal canals of maxillary molars with hand files, rotary, and reciprocating instruments using micro–computed tomographic (micro-CT) imaging and to demonstrate the ability of digital subtraction radiography (DSR) to evaluate AT. MethodsForty-five canals were randomly assigned to either group K, manual K-files; PTN, ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland); or Rec, Reciproc (n = 15 for each group) for preparation. Master apical files were #25, X2 (#25/06), and R25 (#25/08), respectively. Micro-CT imaging was used to measure AT (mm) and CR (mm) at 3 different locations (1, 4, and 7 mm from the apex). VI (mm3) was measured for each root third and for the whole canal. DSR (mesiodistal and buccolingual projections) was used to measure AT at 1 mm from the apex. ResultsAT and CR values were statistically similar across the groups at 1, 4, and 7 mm. AT results obtained for the different locations were similar within each group; CR, in turn, showed statistically lower values at 1 mm. VI was statistically similar in all groups. Both DSR and micro-CT imaging showed that AT always occurred on the outside of canal curvature. The highest mean value obtained for AT was 0.215 mm. ConclusionsAT, CR, and VI were similar for the K, PTN, and Rec groups. AT results were clinically irrelevant. DSR was as effective as micro-CT imaging in AT analysis and could be considered as an alternative method for assessing this outcome.

Effectiveness of digital subtraction radiography in detecting artificially created osteophytes and erosions in the temporomandibular joint.

PurposeErosions and osteophytes are radiographic characteristics that are found in different stages of temporomandibular joint (TMJ) osteoarthritis. This study assessed the effectiveness of digital subtraction radiography (DSR) in diagnosing simulated osteophytes and erosions in the TMJ.Materials and MethodsFive intact, dry human skulls were used to assess the effectiveness of DSR in detecting osteophytes. Four cortical bone chips of varying thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm) were placed at the medial, central, and lateral aspects of the condyle anterior surface. Two defects of varying depth (1.0 mm and 1.5 mm) were created on the lateral, central, and medial poles of the condyles of 2 skulls to simulate erosions. Panoramic images of the condyles were acquired before and after artificially creating the changes. Digital subtraction was performed with Emago dental image archiving software. Five observers familiar with the interpretation of TMJ radiographs evaluated the images. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of the imaging methods.ResultsThe area under the ROC curve (Az) value for the overall diagnostic accuracy of DSR in detecting osteophytic changes was 0.931. The Az value for the overall diagnostic accuracy of panoramic imaging was 0.695. The accuracy of DSR in detecting erosive changes was 0.854 and 0.696 for panoramic imaging. DSR was remarkably more accurate than panoramic imaging in detecting simulated osteophytic and erosive changes.ConclusionThe accuracy of panoramic imaging in detecting degenerative changes was significantly lower than the accuracy of DSR (P<.05). DSR improved the accuracy of detection using panoramic images.

In-vitro quantitative evaluation of the effectiveness of different techniques on the of incipient enamel demineralization

Aim and objective: The aim of this study was to evaluate the effectiveness of three different techniques on treating induced incipient enamel demineralized lesions using digital subtraction radiography (DSR). Materials and methods: Fifteen human sound premolars were used in this study. White spot lesions (WSLs) were established on the buccal, palatal, or lingual surfaces of the samples. Samples were then randomly divided into three equal groups (n = 10). Samples in group A were treated with ACT anticavity fluoride mouthrinse, those of group B were treated with MI paste Plus cream, while those of group C were treated with ICON resin infiltrant. All groups were exposed to a pH cycling, for 30 days excluding weekends where samples were stored in distilled water, during which the treatment regimen was applied. All groups were then exposed to a secondary demineralization attack. Standardized periapical radiographs were taken at four times interval; before any treatment which is considered as the baseline, after WSL creation, after material application, and lastly, after the second demineralization attack. DSR was used for the assessment of WSLs progression. Results: Statistical analysis was conducted using one-way analysis of variance, Tukey's and paired t-tests (P Results: ACT mouthrinse, MI paste Plus, and ICON resin infiltrant are effective materials in treating the incipient lesions and in resisting caries recurrence.