Evaluation of Variations in Root Canal Anatomy and Morphology of Permanent Maxillary Premolars among the Emirate Population using CBCT

Background:

Many types of research have revealed that root canal anatomy differs by race and country based on various national populations, but no study has been conducted on the UAE population.

Objectives:

Identifying the most common morphology of the upper premolars in a group of local and non-local people in the UAE.

Methods:

Cone-beam computed tomography (CBCT) images of 215 intact maxillary premolars were analyzed. The Pearson Chi-squared test and the two samples t-test were applied.

Results:

Most of the maxillary first premolars were two-root formed (90%). Single-rooted teeth were less common (8%). Three-rooted maxillary first premolars represented a low frequency of 1.9%. Most of the maxillary second premolar teeth studied in this research (52%) had two roots. Almost all local and non-local populations had two canals for both first and second maxillary premolar. Only two maxillary first premolars (0.2%) had the three-canal morphology. The most frequent canal morphology in the maxillary first premolar group among local UAE and non-local was type V. The maxillary second premolar group among local UAE was type II (32%). In non-local UAE, type V (25%). In addition, six types of uncommon canal anatomic variants (types 1-2-3, 2-3-2, 3-2-1, 1-2-3-2, 2-1-2-1, and 3-2) were discovered in 3.7% of local UAE and 36.3% of non-local UAE.

Conclusion:

The results suggest a more quantitative approach to maxillary first and second premolar access cavity preparation in the UAE population to prevent errors and iatrogenic damage when identifying the canals.

Comparison of clinical outcomes of non-surgical adjunctive use of the 980-nm diode laser to conventional periodontal flap procedure-a randomised controlled split-mouth clinical trial

Lasers have been found to be effective as an adjunctive in periodontal therapy. The objective of the study was to compare the outcomes of non-surgical adjunctive use of 980-nm diode laser to that of conventional flap surgery in terms of clinical outcome measures and radiographic osseous defect depths. This study was designed as a double-blinded split-mouth randomised controlled clinical trial. A total of fifteen patients (30 quadrants) with generalised periodontitis stage III grade B were randomly assigned test group (diode laser) and control group (conventional flap surgery). Both test and control groups had 15 quadrants each. At 3 months, the probing pocket depth (PPD) was 3.46 ± 0.19 mm (test) and 4.20 ± 0.20 mm (control), with a statistically significant difference between the groups (p = 0.01). Similarly, at 6 months re-evaluation, PPD was 1.46 ± 0.12 mm (test) and 2.33 ± 0.13 mm (control) with a highly significant statistical difference (p = 0.001). Plaque index showed a difference between both test and control groups at baseline, 3 months and 6 months (p = 0.001) while gingival index, modified sulcular bleeding index and radiographic osseous defect depth showed a difference at 3 months and 6 months (p = 0.001). Within the study's limitations, 980-nm diode laser can result in significant improvements in the clinical and radiographic parameters and is very well tolerated by the subjects.

An Audit of the Technical Quality and Iatrogenic Errors of Root Canal Treatment by Undergraduate Dental Students at the University of Sharjah

OBJECTIVES

 The aim of this study was to determine the technical quality of root canal fillings and the presence of iatrogenic errors in the cases treated by undergraduate dental students using radiographic images.

MATERIALS AND METHODS

 This study included 480 root-filled teeth, which were evaluated using intraoral periapical radiographic images. The technical quality of obturation was assessed by observing the length, density, and taperness of the root filling. Ledges, apical transportation, fractured instruments, zipping, and root perforation were recorded as iatrogenic errors. Teeth were classified as acceptable if the technical parameters were adequate and there were no iatrogenic errors.

STATISTICAL ANALYSIS

 Data were statistically analyzed using Pearson's chi-squared test.

RESULTS

 The quality of root filling was acceptable in 183 of the 480 teeth. The rate of acceptable quality was higher for the teeth treated by 4th-year students (41.9%) than for those treated by 5th-year students (27.4%; p = 0.004). Length and taperness were adequate in more of the patients treated by the 4th-year students (p<0.05). There was a significant difference in the incidence of ledge formation and apical transportation in relation to the student's level (p<0.05).

CONCLUSIONS

 The technical quality of root fillings performed without iatrogenic errors by undergraduate dental students was declared acceptable in 38.1% of the assessed teeth. There was a noticeable difference in the quality of root canal treatment between the 4th- and 5th-year students.

CLINICAL RELEVANCE

 The findings demonstrate that periodic assessment of the technical quality of root filling performed by undergraduate dental students provides feedback on curriculum standards.

Application of a Cone-Beam Computed Tomography-Based Index for Evaluating Surgical Sites Prior to Sinus Lift Procedures-A Pilot Study

OBJECTIVES

Radiography-based indices can help surgeons perform detailed examinations of the surgical site and predict the surgical difficulty of cases. We aimed to develop and validate a novel CBCT-based index that can predict the surgical difficulty of sinus-augmentation procedures.

MATERIALS AND METHODS

In the first stage, five experienced dental specialists performed a review of the literature and closed group discussions and designed the novel index. In the next stage, the index was validated. CBCT scans of 30 patients scheduled for sinus-augmentation procedures were evaluated and assigned presurgical CBCT evaluation scores (PSCESs) by five examiners. Subsequently, one oral surgeon performed sinus augmentation using the lateral antrostomy technique and assigned surgical difficulty scores (SDSs) to each of the 30 cases along with 2 observers. The PSCESs and SDSs were statistically analysed to determine the interrater reliability and validity of the index.

RESULTS

The interrater agreement of the PSCES among the five presurgical evaluators was 0.85. The PSCES of the five evaluators had highly significant correlation (P < 0.001, r = 0.68 to 0.76) with the SDS. Regression analysis revealed that for every unit increase in the PSCES, there is 0.46 to 0.57 increase in the SDS value.

CONCLUSION

The results of this pilot study revealed that a novel CBCT-based index can be used as a reliable tool for predicting the surgical difficulty of sinus-augmentation procedures. However, the novel index needs to be tested on a larger sample of patients and evaluators for a more concrete validity and reliability.

Comparative Evaluation of Accuracy of Different Apex Locators: Propex IQ, Raypex 6, Root ZX, and Apex ID with CBCT and Periapical Radiograph-In Vitro Study

OBJECTIVES

This study aimed to validate the accuracy of working length (WL) measurements obtained with the newly introduced Propex IQ apex locator and to compare it with the latest generations of other electronic apex locators, CBCT, and conventional periapical radiographs by using the actual WL measurements obtained by using an endodontics microscope as a reference.

MATERIALS AND METHODS

Thirty-five extracted single-rooted human mandibular first premolars with curvatures from 10° to 20° were selected according to the inclusion and exclusion criteria and cut at the cementoenamel junction to achieve a standard reference point for WL determination. The actual WL was obtained by inserting a size-15 k-file in the root canal until the tip of the file was visible under an endodontic microscope. The definitive WL was measured using Propex IQ (Dentsply Sirona), Raypex 6 (VDW Dental), Root ZX (Morita), and Apex ID (Kerr Dental). In addition, radiographic WL was obtained using periapical radiographs and CBCT. One-way ANOVA was used for comparisons of the WL values, with a p value < 0.05. The percentage of success of each method for determination of the definitive WL was assessed using cross-tabulation and chi-square tests.

RESULTS

CBCT radiographs and Propex IQ apex locator yielded the most accurate WL measurements in comparison with the actual WL measurements (p < 0.05). Raypex 6, Root ZX, and Apex ID yielded more accurate WL measurements than conventional periapical radiographs (p < 0.05). Periapical radiographs yielded the least accurate WL measurements in comparison with the actual WL values (p < 0.05).

CONCLUSIONS

Within the limitations of this study, the Propex IQ apex locator showed higher accuracy than Raypex 6, Root ZX, and Apex ID for WL determination in the root canal. Nevertheless, CBCT radiographs yielded the maximum accuracy for WL measurements.

Cone Beam Computed Tomography Analysis of Root and Root Canal Morphology of First Permanent Lower Molars in a Middle East Subpopulation

Aim:

The aim of this study was to investigate variations in the number of roots and root canals in first permanent lower molars (FPLMs) using cone beam computed tomography (CBCT).

Materials and Methods:

A total of 640 CBCT images were analyzed using SIDEXIS XG software version 2.62 (Sirona Dental Systems, Bensheim, Germany). The entire root anatomy of FPLMs was investigated in three dimensions and the number of roots, root canals, and the number of canals per root were recorded. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) software, version 24, (IBM Corporation, USA) to determine the relationship between root anatomy and gender, age, or tooth location (right or left side).

Results:

The majority of FPLMs had two roots (96%), whereas the remaining 32 FPLMs (4%) had three roots. Almost two-thirds of the sample (62.7%) had three root canals, whereas only three cases (0.4%) of the FPLMs had six canals. When comparing bilateral differences in the distribution of root canals, it was determined that a quarter of FPLMs (24.1%) had an unequal number of canals. Moreover, there were differences in the number of additional canals between the mesial and distal roots with 17.5% of the former having three canals as compared with only 0.5% of the distal root. Interestingly, not more than one canal was observed in all additional root cases. No significant differences were observed in the number of canals between males and females or between right and left sides of the examined FPLMs (P > 0.05).

Conclusion:

Dental clinicians should be aware of the presence of an additional root in 4% of FPLMs, and about a quarter of the cases (27%) had an extra middle mesial canal in the mesial root, which was found to be more prevalent in middle age groups.

A Review of Supernumerary Teeth in the Premolar Region

Supernumerary teeth in the premolar region, unlike other supernumeraries, occur more often in the mandible where they are generally of the supplemental type. Occasionally, they are conical or smaller than normal, particularly in the upper premolar regions. They might occur singly or in multiples, be erupted or impacted, but the majority have been found to be unerupted and asymptomatic. The prevalence of supernumerary teeth in the premolar region has been demonstrated to be between 0.01 and 1 percent depending on the population studied. Interestingly, populations from the East or Africa are known to be the most affected. Various theories have been suggested to explain the etiology of supernumerary teeth in general including both genetic and environmental factors. Furthermore, it has been suggested that supernumerary premolar teeth belong to a third (postpermanent) series, developing from extensions of the dental lamina. Several consequences can result from the presence of supernumerary premolars, especially in the mandible, such as cyst formation, transposition, and other clinical scenarios.

Optimization of scanning electron microscope technique for amniotic membrane investigation: A preliminary study

OBJECTIVE

The objective of this study was to evaluate and compare the two scanning electron microscope (SEM) preparation protocols and determine the better SEM preparation technique to study stem cells on human amniotic membrane (hAM) scaffold.

MATERIALS AND METHODS

Formaldehyde-based protocol and glutaraldehyde-based protocol were compared to evaluate the quality of SEM images for stem cells cultured on hAM scaffold.

RESULTS

The results suggested that formaldehyde-based protocol is better than glutaraldehyde-based protocol in terms of showing clearer topography of the membrane as well as the boarders of the cells. To provide intact surface of the SEM sample and avoid possible ruptures of the hAM or the thin cell layer, it is recommended to perform the dehydration step using graded alcohol concentrations of 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%, one time for each and twice in 100% for 10 min each. Gold sputter-coating step is not recommended as it does not improve the image quality.

CONCLUSIONS

To obtain clear SEM images, it is recommended to run a preliminary study to determine the better chemicals and conditions of sample preparation even when following preexisting protocols.