Retrospective fractal analyses of one-year follow-up data obtained after single-visit nonsurgical endodontic retreatment on periapical radiographs

Evaluation of the long-term structural change caused by root canal treatment in the bone around the tooth by fractal analysis

OBJECTIVE

To evaluate the microarchitecture changes in the trabecular bone around (mesial and distal) the tooth after root canal treatment on panoramic radiographs by measuring the fractal dimension (FD) value change with fractal analysis (FA).

METHODS

One hundred two patients (69 females, 33 males) with a mean age of 33.12 (18-69) years were included. These patients had a clinically healthy, radiologically successful root canal-treated mandibular premolar/molar tooth treated at least 1 year ago. A healthy, untreated contralateral tooth with the same tooth number had to be present (control tooth). Patients were divided into four groups according to their ages (18-24, 25-34, 35-44, and 45 +), teeth into three groups according to treatment time (1-3 years, 4-6 years, and 7-8 years), and three groups according to tooth number (35-45, 36-46, 37-47). FD measurements were made at two rectangular Region of Interest (ROI) with 20 × 60 pixels selected on the mesial and distal of the root with the Image J version 1.3 software program on panoramic radiographs. The comparison of the FD values of the treated and control teeth was performed via the Wilcoxon signed ranks test.

RESULTS

The FD values of mesial and distal regions of root canal-treated molars were statistically significantly higher than the control teeth (p < 0.05). The treatment time, tooth number, and sex and age of the patients did not have a statistically significant effect on the increase in FD value (p > 0.05). There was a correlation between the mesial FD value changing and treatment year (r =  - 0.21, p = 0.035).

CONCLUSION

After the first year of root canal treatment, quantitatively measurable structural changes were observed in the trabecular bone in both the mesial and distal regions of the tooth in all age groups and sexes in the posterior teeth of the mandible.

Investigation of the Effect of Periodontitis on Trabecular Bone Structure by Fractal Analysis

OBJECTIVE

This study aimed to evaluate the trabecular microarchitecture in the interdental region of panoramic radiographs from periodontally healthy individuals and those with stage III/IV periodontitis using fractal analysis (FA), while also assessing the relationship between clinical periodontal parameters and FA outcomes.

STUDY DESIGN

Clinical and radiographic records of 20 periodontally healthy individuals and 19 individuals with stage III/IV periodontitis were included. Clinical measurements including the plaque score, bleeding on probing, probing pocket depth, and clinical attachment level were recorded. A region of interest was selected on panoramic radiographs from the mesial aspect of the mandibular first molar and the distal aspect of the second premolar. The fractal dimension (FD) values for this region were calculated using the box-counting method. The statistical significance of the difference was evaluated at P<0.05.

RESULTS

There was no significant statistical difference in sex between the groups (p > 0.05). Conversely, individuals in the periodontitis group had a significantly higher mean age compared to those in the healthy group (p < 0.01). Clinical measurements were significantly higher in the periodontitis group (p < 0.01). However, no significant differences in FD values were observed between the groups (p > 0.05). In the healthy group, moderate negative correlations were found between FD and clinical parameters (with all p < 0.05), while no such correlations were identified in the periodontitis group (with all p > 0.05).  Conclusion: FA demonstrates potential as a complementary diagnostic tool when used alongside clinical periodontal measurements. However, its effectiveness as a standalone method for reliably distinguishing between healthy individuals and those with periodontitis remains limited. Advanced radiographic analysis can further enhance the identification of anatomical details, thereby improving the accuracy of periodontal evaluations and diagnostics.

Effect of different obturation techniques on treatment results in single-visit non-surgical endodontic retreatment: randomized controlled clinical study

BACKGROUND

Evaluating the effect of different obturation techniques on postoperative pain level and radiographic healing on non-surgical endodontic retreatment (NSER) applied in a single visit in teeth with a single root canal and apical periodontitis (AP).

MATERIALS AND METHODS

Sixty-three teeth from 50 systemically healthy patients (mean age 34.19 ± 9.75 years; 27 women, 23 men) were included in the study. Residual root canal filling materials were removed. All teeth were randomly divided into three groups according to the obturation technique: cold lateral compaction (CLC), continuous wave compaction (CWC), and thermoplasticized gutta-core (TGC). Pain status was evaluated using the Numerical Pain Rating Scale (NRS) in all cases. Periapical index (PAI) scores were recorded in preoperative and postoperative 6-month on the periapical radiographs. Data were analyzed as statistically (IBM, Armonk, NY, USA). The significance level was determined as p < 0.05.

RESULTS

It was found that more postoperative pain occurred in the 3rd-hour interval after CLC and CWC compared to the 7th-day interval (p < 0.05). There was no difference in postoperative pain between obturation techniques in all evaluated time intervals (p > 0.05). There was no difference in the PAI scores recorded at six months between obturation techniques for all periods (p > 0.05). Similar radiographic improvement was observed in all obturation techniques at 6-months (p > 0.05).

CONCLUSION

CLC, CWC, and TGC root canal obturation techniques were found to have similar efficacy after NSER in a single visit in teeth with AP at six months.

TRIAL REGISTRATION

The research was retrospectively registered on the website www.

CLINICALTRIALS

gov with the registration number NCT06226740 on 26/01/2024.

Effect of Fixed and Removable Functional Therapy on Mandibular Anterior Bone Structures: A Fractal Analysis Study

(1) Background and aim: The effects of functional therapies on dentoalveolar and skeletal structures have been investigated in orthodontics for many years. The aim of this retrospective study was to evaluate the changes caused by fixed and removable functional therapy in the mandibular anterior trabecular structures using fractal dimension (FD) analysis. (2) Methods: A total of 60 patients with skeletal and dental class II malocclusion were included in the study and three groups were formed: the untreated control group (CG), the Forsus fatigue-resistant device group (FFRDG), and the Monoblock group (MBG). Bone areas of interest determined in the buccoapical of the mandibular incisors and the symphysis in the lateral cephalometric radiographs taken before (T0) and after (T1) functional therapy were evaluated using FD analysis. The relationship between the FD and IMPA (Incisor Mandibular Plane Angle) angles was evaluated. Parametric and nonparametric tests were used in statistical analysis according to normality distribution. The statistical significance level was determined as p < 0.05. (3) Results: There was no statistically significant difference between the FD values of all groups at T0 (p > 0.05). At T1, buccoapical FD values were significantly lower in FFRDG and MBG compared to the control group (p < 0.05), while symphyseal FD values were not found to be significant (p > 0.05). The IMPA angle was significantly lower in the FFRDG and MBG than in the control group at T0, while it was higher at T1 (p < 0.05). While a significant negative correlation was observed between the IMPA angle and buccoapical FD values in both FFRDG and MBG (p < 0.05), it was not observed with the symphysis FD values (p > 0.05). (4) Conclusions: Trabecular changes caused by functional therapy in the mandibular anterior bone can be evaluated on lateral cephalometric radiographs with FD analysis. It was concluded that orthodontists should ensure controlled changes in the IMPA angle during functional therapy, especially for the decreases in FDs seen in the buccoapical alveolar region due to the forward movement of the mandibular incisors.

Magnetic resonance imaging and fractal analysis findings in temporomandibular joints with disk perforation

OBJECTIVE

This study compared magnetic resonance imaging (MRI) findings and fractal dimension (FD) values in the temporomandibular joints (TMJs) of study patients with disk perforation vs control patients.

STUDY DESIGN

Of 75 TMJs examined with MRI for characteristics of the disk and condyle, 45 were included in the study group and 30 in the control group. MRI findings and FD values were compared for significance of differences between the groups. The frequency of subclassifications was analyzed for differences between the two forms of disk configuration and grades of effusion. Mean FD values were analyzed for differences among subclassifications of MRI findings and between groups.

RESULTS

Examination of MRI variables revealed that the study group had significantly greater frequencies of flattened disks, disk displacement, flattening and combined defects in condylar morphology, and grade 2 effusion (P = .001) Joints with perforated disks had a large percentage of normal disk-condyle relationships (73.3%). Significant differences were discovered between biconcave and flattened disk configuration in the frequencies of internal disk status and condylar morphology. FD values of all patients varied significantly among the subclassifications of disk configuration, internal disk status, and effusion. Mean FD values were significantly lower in the study group with perforated disks (1.07) compared with the control group (1.20, P = .001).

CONCLUSIONS

MRI variables and FD can be useful in investigating intra-articular TMJ status.

In Situ Zymography Analysis of Matrix Metalloproteinases Activity Following Endodontic Irrigation Protocols and Correlation to Root Dentine Bond Strength

The objective was to evaluate the effect of different root canal irrigating solutions on the activity of matrix metalloproteinases (MMPs), and correlation to the push-out bond strength (PBS) and nanoleakage expression (NL) in the root dentin. Seventy-two single-rooted teeth were treated endodontically and distributed into four groups (n = 6 for in-situ zymography, n = 10 for PBS, and n = 2 for NL per group) according to the irrigating solutions used: (I) saline (S); (II) 5.25% sodium hypochlorite (SH); (III) 5.25% SH + 10% citric acid (CA); and (IV) 5.25% SH + 10% CA + 0.2% chlorhexidine (CHX). After root canal obturation, post space was prepared to receive the glass fiber post. Dual-cure resin was used for luting and light polymerization was performed. The root/fiber post assemblies were sectioned and subjected to in situ zymography, and PBS and NL expression analysis tests. The enzymatic activity was quantified and expressed as a percentage of the green fluorescence, while fractographic evaluation was performed after PBS with a stereomicroscope, and data were statistically analyzed at p < 0.05. The zymography analysis shows high expression of MMPs in the middle third of the root in all groups, while the most abundant activity of MMPs following the irrigating solutions is observed in groups I and III, where saline and citric acid are used, respectively. Inversely, group IV, where chlorhexidine is the final rinse, records the lowest MMP activity with the highest PBS, and the statistical analysis of the groups are ranked as: IV > II > III > I (p < 0.05). The combination of SH, CA, and CHX results in lower expression of MMPs and higher push-out bond strength of fiber posts to root dentin, with no difference seen in the nanoleakage expression (p > 0.05); hence, this irrigation regime with chlorhexidine as a final rinse is more favorable than other combinations in ensuring optimal adhesion to root dentine.