The Impact of Coronal Flaring Files on Pericervical Dentin Thickness in Mandibular Molars

INTRODUCTION

This study aimed to assess the influence of different coronal flaring files on dentin removal in mandibular teeth using cone-beam computed tomographic (CBCT) images.

METHODS

CBCT images of 48 mandibular molar teeth were acquired and randomly divided into 2 main groups, with each main group further divided into 3 subgroups. In the first main group, root canal preparation was performed using TruNatomy (Dentsply Sirona, Ballaigues, Switzerland), ProTaper Gold (Dentsply Sirona), and One Curve (Micro-Mega, Besancon, France) files without the use of coronal flaring files. In the second main group, root canal preparation was performed using the same files with the use of coronal flaring files. After the completion of root canal preparation, a second set of CBCT images was obtained. Subsequently, the dentin removal and remaining critical dentin were assessed by measuring at 4 distinct points below the furcation level. Data were compared between groups using the Mann-Whitney U and Kruskal-Wallis tests with alpha set at 5%.

RESULTS

The ProTaper Gold files demonstrated higher dentin removal compared with the TruNatomy files. In the no-flaring groups, the One Curve files exhibited greater dentin removal than the TruNatomy files at specific levels. The use of coronal flaring files generally did not significantly impact dentin removal, except for certain cases in the TruNatomy and ProTaper Gold groups.

CONCLUSIONS

The TruNatomy instrument group was more effective in preserving pericervical dentin compared with the other instrument groups. Coronal flaring files can be confidently used to preserve critical dentin during root canal treatment.

The effect of ibuprofen sustained release oral premedication on intraoperative and postoperative pain: A randomised clinical trial

The aim of this study was to assess the effect of ibuprofen sustained release (SR) oral premedication on the efficacy of buccal infiltration (BI) with intraoperative and postoperative pain after single-visit root canal treatment. Sixty patients diagnosed with symptomatic irreversible pulpitis and apical periodontitis in mandibular molar were divided into two groups. Group SR received ibuprofen SR 800 mg and group PL received placebo capsule 1 h before 3.6 mL articaine BI injection. Pain was recorded using a modified visual analogue scale and postoperatively at intervals 6, 24 and 48 h. Group SR showed a significantly higher anaesthetic success rate (73.3%) compared to group PL (46.7%) (p < 0.05). Intraoperative and postoperative pain was significantly higher in group PL compared to group SR (p < 0.05). Premedication of ibuprofen SR improved the efficacy of primary BI in mandibular molars with symptomatic irreversible pulpitis and decreased postoperative pain at 6 and 48 h.

Efficacy of the GentleWave System in the removal of biofilm from the mesial roots of mandibular molars before and after minimal instrumentation: An ex vivo study

AIM

To compare the efficacy of Enterococcus faecalis biofilm removal using the GentleWave System (GWS) (Sonendo Inc, CA) on non-instrumented versus minimally instrumented root canal systems.

METHODOLOGY

Thirty-four mandibular molars were autoclaved and allocated to four groups: Negative control (n = 5); positive control (n = 5); Group 1: non-instrumentation + GWS (NI + GWS) (n = 12); and Group 2: minimal instrumentation + GWS (MI + GWS) (n = 12). Of 34 samples, 24 samples with Vertucci type 2 configuration within the mesial root of each sample were allocated to Groups 1 and 2 and then matched based on the working length and root canal configuration. After inoculation of samples with E. faecalis for 3 weeks, the GWS was used on Group 1 without any instrumentation and Group 2 after instrumentation of mesial canals until size 20/06v. CFU and SEM analysis were used.

RESULTS

Log10 (CFU/mL) from the positive control, and Group 1 and 2 were 7.41 ± 0.53, 3.41 ± 1.54, and 3.21 ± 1.54, respectively. Both groups showed a statistically significant difference in the reduction of viable E. faecalis cells compared to the positive control (Group 1 [p = .0001] and Group 2 [p < .0001]), whilst showing no significant difference between the two tested groups (p < .05).

CONCLUSION

The use of GWS on the non-instrumented root canal system could be an effective disinfection protocol in removing the biofilm without dentin debris formation.

A Cone Beam Computed Tomography-Based Investigation of the Frequency and Pattern of Radix Entomolaris in the Saudi Arabian Population

Background and Objectives: An understanding of the anatomical complexity of teeth is a significant factor for a successful endodontic treatment outcome. The aim of this study was to explore the frequency and pattern of distribution of radix entomolaris (RE) in mandibular first molars (MFMs) of a Saudi Arabian subpopulation using CBCT scans. Materials and Methods: This study was conducted at dental clinics of Qassim University from February to May 2023 by evaluating CBCT scans that were previously obtained for diagnostic purposes. Scans of Saudi national patients with bilaterally present MFMs and fully formed root apices were included. Conversely, scans with one/or two missing MFMs, MFMs with incomplete root apices, full- or partial-coverage prosthesis, endodontic treatment, and associated radicular resorption were excluded from study. A total of 303 CBCT scans with 606 bilateral MFMs were analyzed by two calibrated evaluators for the presence of, and type according to Song's typolgy of RE. The data were analyzed using SPPS-24. The descriptive variables were documented as frequencies and percentages. The chi-square test was used to determine the association between the prevalence of RE with the gender, jaw side and age group. Both inter-rater and intra-rater agreements were estimated for detecting and classifying RE using Cohen's kappa test. Results: The sample had 63.7% males and 36.3% females. The prevalence of RE was 6.6%, with Song's type III (57.5%) as the most common variant. Absolute agreement was noted between the raters about the presence of RE and very strong agreement was noted for the classification of the RE. Conclusions: RE is an uncommon finding among the mandibular first molars of the Saudi population without any gender and quadrant predilection. The clinicians' knowledge of the presence and Song's type of RE may contribute towards the enhancement of endodontic treatment outcomes.

Prevalence of Radix Entomolaris in Mandibular Permanent Molars Analyzed by Cone-Beam CT in the Saudi Population of Ha'il Province

BACKGROUND

The present study aimed to examine the prevalence of radix entomolaris (RE) in the mandibular permanent molar within a specific sub-population in Saudi Arabia.

METHODS

A comprehensive analysis was conducted on 499 cone-beam computed tomography (CBCT) scans of a mandibular molar from a sample of Saudi patients aged between 18 and 65. The primary objective of this study was to investigate the anatomical characteristics of mandibular permanent molars, specifically focusing on the number of roots present. The chi-square test was employed to examine the relationship between various variables.

RESULTS

In the case of mandibular first molars, it was observed that 95.3% of these molars exhibited a bifurcated root structure. In comparison, the remaining 4.7% displayed a triradicular configuration within the sample population under investigation. Although there were some variations, no significant differences in the number of roots were observed between males and females or left and right sides (p > 0.05). In the case of mandibular second molars, it was observed that 96.9% of them exhibited a bifurcated root structure, whereas 2.5% displayed a trifurcated root configuration, and a mere 0.6% possessed a single root. There were no statistically significant variations in the number of roots between males and females or left and right sides (p > 0.05).

CONCLUSIONS

The identification of RE was observed in the mandibular molars. Moreover, the discovered RE roots were predominantly found in the mandibular first molar, displaying a tendency for bilateral occurrence in both male and female individuals.

Prevalence and morphological analysis of isthmuses in mandibular molars of the Indian population: A micro-computed tomographic study

Objectives

This study evaluated the prevalence, configurations, and correlation of isthmuses at coronal, middle, and apical root 3rd in mandibular molars of the Indian population using micro-computed tomography μCT).

Materials and Methods

One hundred and five permanent mandibular molar teeth were scanned under μCT. The axial sections were analyzed at the coronal, middle, and apical thirds of the root for isthmus types and classified according to Hsu and Kim's classification. Descriptive statistics for each isthmus type were calculated. The correlations between the apical, middle, and coronal thirds of the root were determined using Pearson's correlation coefficient.

Results

Type IV isthmus was the most common in the coronal third of the mesial root of mandibular 1st molar (42.9%), while Type V was prevalent in the coronal third of the mesial root of 2nd molar (42.9%). Type I isthmus was found to be highly prevalent in the middle 3rd (71.4%) and apical 3rd (61.9%) of mesial roots of 1st molars, and in the middle 3rd (71.4%) and apical 3rd (42.9%) of mesial roots of 2nd molars. Type V isthmus was the most prevalent in all the thirds of the distal roots of both 1st and 2nd molars, ranging from 40% to 50%. Furthermore, a strong correlation of 0.965 (P < 0.01) was found between the isthmuses in the apical and middle thirds of roots.

Conclusion

There are variations in the prevalence and type of isthmuses across different sections of the root, including the presence of atypical isthmuses. Micro-CT with high-resolution imaging and three-dimensional reconstruction is crucial for investigating root canal morphology. Clinicians could benefit from considering demographic characteristics to better predict the presence of isthmus variations.

Clinical Relevance

The isthmus configurations and frequency differ at each section of mandibular teeth.

Internal morphology of distal roots of mandibular first molars revealed by computed microtomography

To evaluate the internal morphology of 100 distal roots of mandibular first molars using micro-CT. Teeth were scanned to characterise: Vertucci type, root length, canal shape, presence and location of accessory canals, and the number of foramina at 4 mm from the apex, presence of root isthmus and the length from the primary canal to the apical foramen. Vertucci type I was found in 57% of cases, followed by V (27%). The most common cross-section 1 mm from the apex was oval (49%) and circular (38%). The average root length was 16.06 mm (16.61-19.02 mm). The mean foramen size was 0.32 and 0.53 mm for the minor and major diameters, respectively. The volume, surface area and SMI were 7.84 mm3 , 68.87 mm2 and 1.52 mm, respectively. Root isthmi were found in 47% of the samples, and the length mean from the primary canal to the apical foramen was 2,03 mm. The internal morphology of the distal roots of mandibular first molars may be complex and shows variations.

Cone-Beam Computed Tomography (CBCT)-Based Assessment of the Alveolar Bone Anatomy of the Maxillary and Mandibular Molars: Implication for Immediate Implant Placement

Purpose This study aims to examine specific aspects of socket morphology, including buccal and palatal/lingual bone width, interradicular bone (IRB) width, and assessments of root apices and furcation proximity to the vital structures of the maxillary and mandibular first and second molars using cone-beam computed tomography (CBCT). Materials and methods The study involved the analysis of 400 maxillary and mandibular first and second molars. Various measurements were taken to assess socket morphology, including mesiodistal (MD) and buccolingual (BL) width, buccal and lingual bone thickness at 2 mm apical to the alveolar crest, IRB width at 2 mm from the furcation, and the distance between the root apices and furcation to vital structures, such as the floor of the maxillary sinus (FMS) and inferior alveolar nerve (IAN). Results The mesiobuccal (MB) root of the second molar commonly intruded into the sinus, followed by the palatal root of the maxillary first molar. The mean FMS-F distance was 7.17 + 3.98 mm, and it was 7.2 + 2.72 mm for maxillary first and second molars, respectively. The mean IRB width was 2.77 + 0.96 and 2.29 + 0.74 mm for the first and second molars. The mandibular second molar had the shortest distance to the IAN in comparison to the first molar. For maxillary teeth, 7% of the first and 4% of the second molars presented alveolar anatomy adequate for immediate implant placement, compared to 84% and 50% of mandibular first and second molars. Conclusion Understanding the local alveolar bone anatomy of molars and its relationship to vital structures is crucial for the effective planning of implant treatments.

Comparing intraosseous computerized anaesthesia with inferior alveolar nerve block in the treatment of symptomatic irreversible pulpitis: A randomized controlled trial

AIM

The aim of this study was to compare the cardiovascular effects (heart rate, oxygen saturation (SpO₂ )_, systolic and diastolic blood pressure) and the anaesthetic efficacy of intraosseous computerized anaesthesia (ICA) versus inferior alveolar nerve block (IANB) in Symptomatic irreversible pulpitis (SIP).

METHODOLOGY

The study protocol was registered with ClinicalTrials.gov (NCT03802305). In a randomized, prospective clinical trial, 72 mandibular molar teeth with SIP were randomly allocated to conventional IANB injection (n = 36) or ICA injection (n = 36), both with 1.8 mL of 4% articaine with 1:100,000 epinephrine. The primary objective was to assess the cardiovascular parameters (heart rate, oxygen saturation, blood pressure) before, during, and after the anaesthesia. The secondary objectives were to compare ICA with IANB for success and postoperative outcomes for up to 3 days.

RESULTS

The maximum increase in heart rate in the ICA group was greater than in the IANB. Other cardiovascular parameters did not show differences throughout the clinical procedure. There were no statistically significant differences (P > .05) between groups for sex, age, or anxiety. The total success rate of ICA (91.43%) was significantly higher (P = 0.0034) than that of IANB (69.44%).

CONCLUSIONS

This study establishes that ICA is safe and efficient in the first intention for the treatment of SIP of the mandibular molar.

Exploring a Paradigm Shift in Primary Teeth Root Canal Preparation: An Ex Vivo Micro-CT Study

Traditional hand instrumentation is a commonly used technique to perform pulpectomy in deciduous teeth by most specialists in pedodontics. Lately, dentists have embraced rotary instrumentation as a safe and effective alternative. This study aimed to compare the efficacy of root canal preparation in extracted primary molars between manual and two rotary file systems using micro-CT. Thirty-six extracted human second primary mandibular molars were divided into three groups according to the instrumentation method: (1) Manually instrumented (MI) group (n = 9) in which the teeth were treated using K-files up to size 30; (2) Kedo-Ssystem (KS) group (n = 9); (3) ProTaper Gold system (PTG) group (n = 10) and control group (n-8). Each tooth was scanned before and after the retrograde root canal preparation. Residual dentin volume was calculated using micro-CT scans to evaluate the technique's efficacy. Additionally, the preparation time and procedural errors were recorded for each tooth preparation. A one-way ANOVA test was carried out to compare the groups' dentin volume and preparation time. The mean preparation time using the manual method (13.14 min) was more than two times longer than that of the rotary techniques (4.62 min and 6.45 min). The manual preparation method using a K-file removed almost half the root canal material when compared with the rotor method (p = 0.025). Conclusion: our results suggest that rotary instrumentation is more efficient for root canal preparation in primary teeth than the traditional manual method. This finding may call for a paradigm shift in current clinical practices, where manual instrumentation is still commonly preferred.

The global prevalence of middle mesial canal in mandibular first and second molars assessed by cone beam computed tomography: A systematic review and meta-analysis

BACKGROUND

This meta-analysis sought to identify the in vivo prevalence and influencing factors of middle mesial canal (MMC) in mandibular first and second molars based on cone-beam computed tomography (CBCT) scans.

METHODS

MEDLINE/PubMed, Web of Science, Scopus, SciELO, Google Scholar databases/search engines were searched in period between 15^th and 21^st November 2022, to retrieve the in vivo CBCT-based studies that assessed the prevalence of MMC in mandibular first and/or second molars. The studies were strictly assessed using pre-defined inclusion and exclusion criteria for relevancy and eligibility through screening the title and abstract, and then assessed through reading the full texts using the same criteria. Subsequently, the fulfilled studies were assessed qualitatively using the Newcastle-Ottawa Quality Assessment Scale, and quantitatively using meta-analysis to calculate the pooled prevalence rates of MMC. The publication bias was assessed using funnel plot and Egger's test.

RESULTS

Out of 1,122 studies, 33 studies comprised 13,349 and 7,624 mandibular first and second molars, respectively, were eligible for inclusion. Twenty studies scored high quality, while thirteen scored moderate quality. The global prevalence of MMC in the first molar was 4.4% (95% CI = 0.035-0.053, P<0.001), significantly higher than that of the second molar which was 1.3% (95%, CI = 0.008-0.018, P<0.001). Gender, molar side, and age were not influencing factors of MMC prevalence.

CONCLUSION

The prevalence of MMC is not uncommon, being higher in the mandibular first molar compared to the mandibular second molar. The prevalence of MMC is not influenced by age, molar's side, and gender.

Taper 0.06 Versus Taper 0.04: The Impact on the Danger Zone

INTRODUCTION

This study aimed to evaluate the effects of root canal enlargement on the danger zone (DZ) of mandibular molars.

METHODS

Thirty mesial roots of mandibular first molars were scanned in micro-computed tomography (S1). Canals were sequentially enlarged with rotary instruments up to sizes 30/0.04 (S2) and 30/0.06 (S3). The dentin thickness was measured at 0.1-mm intervals after each preparation step (n = 2964 slices). Root level and position of the DZ were also recorded. Data were compared using analysis of variance with Bonferroni pairwise comparison, Cochran's Q method, and Pearson's test (α = 5%).

RESULTS

Comparing the specimens before (S1) and after (S2 and S3) preparations showed a significant reduction in the thickness of the DZ (P < .05), as well as between S2 and S3 steps (P < .05). At S1, the DZ was mostly located in the middle third of the root, but after preparation, it shifted toward the coronal direction (P < .05). Both S2 (P = .004, r = 0.508) and S3 (P = .004, r = 0.506) preparation steps showed a positive correlation between canal length and the root level of the DZ. At S1, the DZ was positioned toward the distal and mesial in 73.4% (n = 22) and 26.6% (n = 8) of the specimens, respectively. After S3, the number of specimens with DZ positioned toward the mesial aspect of the root significantly reduced to 3.3% (n = 1), whereas none of the specimens with DZ positioned toward the distal changed its position after root canal enlargements (P > .05).

CONCLUSION

Overall, the enlargement of mesial canals of mandibular first molars with final instruments sizes 30/0.04 and 30/0.06 affected the thickness, root level, and position of the DZ.

Inferior Alveolar Nerve Block Success of 2% Mepivacaine versus 4% Articaine in Patients with Symptomatic Irreversible Pulpitis in Mandibular Molars: A Randomized Double-Blind Single-Centre Clinical Trial

AIM

To assess inferior alveolar nerve block (IANB) success of 2% mepivacaine (Scandonest 2%, Septodont, France) and 4% articaine (Septanest 4%, Septodont) in patients with symptomatic irreversible pulpitis (SIP) in mandibular molars during access cavity preparation and instrumentation.

METHODOLOGY

Three hundred and thirty patients with moderate-to-severe pain in mandibular molars with SIP randomly received either 3.6 mL 2% mepivacaine hydrochloride with 1:100 000 adrenalin or 3.4mL 4% articaine hydrochloride with 1:100 000 adrenalin (n=165). Intraoperative pain (IOP) intensity was assessed during access cavity preparation and canal instrumentation using 11-point numerical rating scale (NRS). Overall success was considered if the patient felt no-to-mild pain without the need of supplemental anaesthesia throughout treatment; the incidence of need for supplemental anaesthesia was also recorded. Data were statistically analyzed using Mann Whitney U and Chi² (χ² ) tests. Relative risk (RR) and 95% confidence interval (CI) of anaesthetic failure was calculated. The effect of predisposing factors on outcome variables was assessed using multivariable regression analyses. None of the participants reported any adverse effects.

RESULTS

Baseline variables were balanced between groups (p>0.05). The IOP intensity during access cavity preparation and canal instrumentation was similar for both groups (p>0.05). IOP intensity was associated with preoperative pain intensity and tooth type (p<0.05). Overall anaesthetic success rate was 35.8% for mepivacaine and 41.2% for articaine (p>0.05) with a relative risk of failure [95%CI] 1.09 [0.92, 1.30]. The need for supplemental anaesthesia occurred 43.6% and 38.2% with mepivacaine and articaine respectively (p>0.05; RR [95%CI]: 1.14 [0.88, 1.48]). Preoperative pain level and age were associated with the need for supplemental anaesthesia.

CONCLUSIONS

2% mepivacaine and 4% articaine demonstrate similar IANB success rates for mandibular molars with SIP. Intraoperative pain experience during endodontic treatment can be associated with preoperative pain, tooth type and age.

Influence of access cavity preparation on the dentine thickness of mesial canals of mandibular molars prepared with reciprocating instruments

AIM

To evaluate the influence of traditional and conservative access cavity preparations on the remaining dentine thickness in the coronal third of mesial canals of extracted mandibular molars prepared with reciprocating instruments using micro-computed tomography as the analytical tool.

METHODOLOGY

Seventy extracted mandibular molars were scanned at a pixel size of 19 μm. From this initial sample, 20 teeth were selected, pair-matched and distributed into two groups (n = 10) according to the access cavity preparation: traditional (TradAC) or conservative (ConsAC). The root canals were sequentially enlarged with Reciproc Blue R25 (size 25, 0.08v taper) and R40 (size 40, 0.06v taper) instruments. A new scan was performed and the postoperative stacks were coregistered with their respective preoperative datasets. A colour-coded cross sections of the roots were created and used to identify and measure the smallest dentine thickness related to both MB and ML canals at 1.0-mm intervals from the furcation level of up to 5 mm in the apical direction, in both mesial and distal aspects of the roots, before and after preparation. The statistical analyses were performed with paired-samples t-test, independent-samples Student T-test and Chi-Square test with a significance level of 5%.

RESULTS

At all levels of both groups, dentine thickness before preparation was greater than after preparation (p < .05). No difference in the percentage of dentine reduction was observed between TradAC and ConsAC groups (p > .05), but a significantly greater reduction was observed to the distal aspect of the roots (p < .05). After root canal preparation, dentine thinner than 0.5 mm was observed mostly along the distal aspect of the root (10% to 15%) of the MB and ML canals, with no influence of the access cavity type on its incidence to either mesial (X²  = 1.66; p = .2) or distal (X²  = 0.40; p = .5) directions. In the TradAC group, dentine thickness in most slices was greater than 1.0 mm after preparation (n = 124) whilst, in the ConsAC, it ranged from 0.5 to 1.0 mm (n = 136).

CONCLUSION

Traditional or conservative access cavity preparation in extracted mandibular molars did not influence the remaining dentine thickness in the coronal third of mesial canals enlarged with thermomechanically treated nickel-titanium reciprocating instruments.

Cementum Malformations-Diagnostic Dilemma: Study in Western Maharashtra Population

Aim:

The present study was study to observe incidence of cemental malformations related to mandibular molar roots.

Materials and Methods:

All cases requiring radiographs of mandibular molars reporting to author during 2011–2019 were included in this study. Mandibular molars had been observed for any radiographic malformations. Any such alterations were noted.

Results:

Author has screened about 522 intraoral periapical radiographs in this study. A total of 63 cases of root malformations reported with two cases of cementoma were observed in this study. Both these cases were diagnosed as benign cementoblastoma (BC) on excisional biopsy.

Conclusion:

In this study, we have observed that incidence of cemental malformations is 1.2% and of BC is 0.38% as compared to overall incidence of 1%–6% in Western Maharashtra.

Nonsurgical Management of Strip Perforation Using Platelet-Rich Fibrin and MTA by Matrix Concept - A Case Report with One Year Follow-up

Iatrogenic errors happen especially during endodontic treatment even with the experienced clinicians. It is impossible to predict the occurrence of an event. Although many of them can be corrected and managed successfully, few conditions might have the worst prognosis leading to uneventful extraction. The present case report highlights a 1-year follow-up of managed strip perforation in mesial canals of mandibular first molar, nonsurgically using MTA obturation. The present challenging case gives an insight on the importance of regenerative capacity and osteogenic potentiality of bioactive materials, when appropriate tissue engineering concepts are applied.

Third Molar Autotransplantation: An Alternative to Dental Implant - 9 Years Follow up of a Case

Autogenous tooth transplantation is the surgical movement of tooth from one location in the mouth to another in the same individual. It is an excellent option with good functional and esthetic outcome for rehabilitating young patients with growing alveolar bone and replaces missing tooth with a natural tooth rather than a prosthesis or an osseointegrated implant. This case reports discusses a 9 years follow up of a successful autotransplantation case of third molar in place of first molar justifying autotransplantation to be a viable treatment option in present day implant dentistry practice.

Anaesthetic efficacy of 2% lidocaine with different concentrations of epinephrine (1:80,000 and 1:200,000) in intraligamentary injection after a failed primary inferior alveolar nerve block: a randomized double-blind study

Introduction: The present study evaluated the anaesthetic efficacy of 2% lidocaine with 1:80,000 epinephrine vs. 2% lidocaine with 1:200,000 given as supplemental intraligamentary injections after a failed inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis. The effect of these solutions on the heart rate was also evaluated.Methods: One-hundred-eighteen adult patients with symptomatic irreversible pulpits in a mandibular first or second molar, received an initial IANB with 2% lidocaine with 1:80,000 epinephrine. Pain during the endodontic treatment was assessed using a visual analogue scale (Heft-Parker VAS). Eighty-eight patients with unsuccessful anaesthesia were randomly allocated to one of the two treatment groups: one group received 0.6 mL/root of supplementary intraligamentary injection of 2% lidocaine with 1:80,000 epinephrine; while the second group received 2% lidocaine with 1:200,000 epinephrine. Endodontic treatment was re-initiated. Success after primary injection or supplementary injection was defined as no or mild pain (pain score ≤54 mm on HP VAS) during access preparation and root canal instrumentation. Heart rate was monitored using a finger pulse oximeter. The anaesthetic success rates were analyzed with the Pearson chi-square test at 5% significance levels. The heart rate changes were analyzed using the t-test.Results: The anaesthetic success rate in patients receiving supplementary intraligamentary injections in 1:80,000 epinephrine group was 82%, while the intraligamentary injections with 2% lidocaine with 1:200,000 epinephrine were successful in 57% of cases. The difference was statistically significant (χ²=6.4, p = .011). There was no significant effect of both the anaesthetic agents on the mean heart rate.Conclusions: Both 2% lidocaine with 1:80,000 epinephrine and 2% lidocaine with 1:200,000 epinephrine improved the success rates after a failed primary anaesthetic injection. The 1:80,000 epinephrine group was significantly more successful.

C-shaped canal configuration in mandibular premolars and molars: Prevalence, correlation, and differences: An In Vivo study using cone-beam computed tomography

AIMS

To evaluate the prevalence, correlation, and differences of C-shaped canal morphology in mandibular premolars and molars by means of cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

A total of 1433 mandibular premolars and molars CBCT scans from the Saudi population were evaluated. Axial sections of the roots were acquired at coronal, middle, and apical levels to evaluate C-shaped canals types. The prevalence, correlation, differences of C-shaped canals, bilateral/unilateral presence, gender differences, and location of external grooves on roots were assessed.

RESULTS

The prevalence of C-shaped canals in the first premolars was 1.5%, 0.80% in second premolars and 7.9% in second molars, whereas C-shaped canals were absent in first molars. No correlation was found between the presence of C-shaped canals within premolars and molars and between the two groups in the same individual. Both premolars and molars exhibited different types of C-shaped canals, C2 being predominant in premolars and C3 in second molars. Longitudinal external grooves were mostly located on mesiolingual (ML) surface in premolars and lingual in molars. Females showed more prevalence of C-shaped canals in second molars and no differences in premolars. Bilateral symmetry and unilateral presence in premolars and second molars were not significant.

CONCLUSIONS

Although the prevalence of C-shaped canals is significantly higher in mandibular second molars, they are also found in mandibular premolars but in small percentages. No significant differences were found between both genders and both sides. Since they exhibit unpredictable morphology and differences across the root length, the use of small field CBCT is recommended when such anatomy is presented in a tooth indicated for root canal treatment for better management.

Incidence of Middle Mesial Canals Based on Distance between Mesial Canal Orifices in Mandibular Molars: A Clinical and Cone-beam Computed Tomographic Analysis

INTRODUCTION

This study evaluated the presence of midmesial canals (MMCs) in a random sample of mandibular molars and the relationship of the intracanal distance between mesiobuccal (MB) and mesiolingual (ML) canal orifices.

METHODS

Fifty-one extracted mandibular molars were divided into samples of 3 to 4 teeth, mounted in plaster and boxing wax, and immersed in water before cone-beam computed tomographic (CBCT) imaging. Two endodontic residents completed the access openings. The teeth and the CBCT images were interpreted for the presence of MMCs and the mesial intracanal distance. CBCT software measured the distance between the buccal of the MB canal to the lingual of the ML canal at the pulpal floor to determine the average length between the canals.

RESULTS

Seven distinct MMCs were seen both clinically (incidence of 13.725%) and on the CBCT images. Twenty-seven teeth (52.94%) had ambiguous broad isthmi between the MB and the ML orifices. MMCs were present at the furcation level but merged with the MB or ML canal toward the apex in 6 of 7 teeth (85.71%). The mean distance between the mesial canals in teeth with MMCs was 3.643 mm, and it was 3.818 mm for teeth without MMCs. According to independent sample t testing, the P value was >.05.

CONCLUSIONS

The incidence of MMCs in mandibular molars appears consistent with the literature. However, there does not appear to be a statistically significant difference in the mesial intracanal distance in teeth with and without MMCs. Visualization of MMCs on CBCTs may be subjective. There does not appear to be a correlation between the presence of MMCs and an increased or decreased mesial intracanal distance.

Prevalence of C-shaped mandibular molars in the Portuguese population evaluated by cone-beam computed tomography

Objective:

The purpose of this study was to evaluate the prevalence of first and second C-shaped mandibular molars in a Western European population of Portuguese Caucasians.

Materials and Methods:

Patients having both routine panoramic radiograph and presurgical cone-beam computed tomography (CBCT) exams were selected. The CBCT examination was performed at five different axial levels and the mandibular molars were classified as C-shape according to the Fan criteria. Differences between genders, age groups, left and right side, type of tooth, and root concavity side were determined. The molars were classified as nonfused roots (NFRI–II), FRI–III, or single root with single canal (SS) groups, using the panoramic radiograph. The prevalence of C-shaped anatomy was calculated to each group.

Results:

A total of 1783 teeth (695 first molars and 1088 second molars) from 792 patients were included in the study. The prevalence of C-shaped configurations was 0.6% and 8.5% to mandibular first and second molars, respectively. The differences between gender, teeth, and root concavity direction were considered statistically significant (P < 0.05). The FR had a significantly higher rate of C-shapes when compared to NFR (P < 0.05). Intrarater reliability was 93.6%.

Conclusions:

The FR radiographic appearance may be considered a predictor of this anatomy. Second mandibular molars and females had a higher incidence ratio. Apparently, the mandibular C-shaped anatomy is more common in the population of this study than that has been previously reported for the European population.

Evaluation of Root and Root Canal Morphology of Mandibular First and Second Molars in a Greek Population: A CBCT Study

Objective:

Τo study the number of roots, canal configurations, and frequency of morphological variations in mandibular first and second molars in a Greek population.

Methods:

This study examined 478 mandibular first molars and 524 mandibular second molars using a high-resolution cone-beam computed tomography (CBCT). The number of roots was recorded and the root canal configuration was categorized based on the classification by Vertucci. The presence and configuration of C-shaped root canals were recorded and they were classified according to the Fan classification. The symmetry between the right and the left side was also evaluated.

Results:

Among the mandibular first molars, 0.2% teeth were single-rooted, 96.4% were two-rooted, and 3.3% were three-rooted. In the mandibular second molars, 12.2%, 82.8%, and 4.9% were single-rooted, two-rooted, and three-rooted, respectively. In two-rooted mandibular first and second molars, the most frequent root canal pattern observed was Vertucci’s type II in the mesial root (69.8% and 64.1%, respectively) and Vertucci’s type I in the distal root (81.7% and 97.7%, respectively). Three-rooted molars showed one oval-shaped mesial root and two distal roots (56.2% in first molars, 65.4% in second molars), where each distal root contained a single root canal (type I), and the mesial root presented either type II (53.3%), IV (26.6%), I (13.3%), or V (6.6%) canal configurations. C-shaped canals were only detected in mandibular second molars (5.3% of teeth, 10.8% of individuals), and bilateral occurrence was observed in 24.5% patients. The most frequent root canal pattern was Fan’s C1 type at the orifice, followed by C3a and C3b in the coronal and middle third, which joined into a single canal (C4) apically.

Conclusion:

The characteristics of the root and root canal anatomy of the mandibular first and second molars of Greek individuals were similar to those observed in Caucasians. However, the higher incidence of third roots in mandibular molars in Greek individuals compared to Caucasians requires absolute clinical awareness.

Analysis of mandibular second molars with fused roots and shallow radicular grooves by using micro-computed tomography

Aim:

This study aimed to describe the morphological and morphometric aspects of fused mandibular second molars with radicular shallow grooves using micro-computed tomography (CT).

Materials and Methods:

Eighty-eight mandibular second molars with fused roots were scanned in a micro-CT scanner at a voxel size of 19.6 μm. After reconstruction, only molars without C-shaped roots and presenting shallow radicular grooves were selected. 30 molars were chosen for further analysis. Canal cross-sections were classified according to Fan's modified classification (C1, C2, C3, and C4) and morphometric parameters at the apical region, examination of accessory foramina and tridimensional configuration were evaluated.

Results:

Three-dimensional reconstructions indicated a higher prevalence of merging type (n = 22). According to Fan's modified classification, the C4 configuration was predominant in the 3 apical mm. Roundness median values revealed a more round-shaped canals at 3 mm (0.72) than at 2 (0.63) and 1 (0.61) mm from the apex. High values of major and minor diameters were observed in the canals of these evaluated sections. In addition, few accessory apical foramina were observed at 1 and 2 mm from the apex. The average distance between last accessory foramina and the anatomic apex was 1.17 mm. A less complex internal anatomy is found when a mandibular second molar presents fused roots with shallow radicular grooves. The merging type canal was frequently observed. Moreover, the C4 configuration was predominant at a point 3 mm from the apex and presented rounded canals, large apical diameters, and few accessory foramina. The cervical and middle thirds presented C3 and C1 canal configurations most frequently.

Conclusion:

A minor morphological complexity is found when fused mandibular second molars present shallow radicular grooves.

Efficacy of Articaine versus Lidocaine in Supplemental Infiltration for Mandibular First versus Second Molars with Irreversible Pulpitis: A Prospective, Randomized, Double-blind Clinical Trial

INTRODUCTION

Profound pulpal anesthesia is difficult to achieve in mandibular molars with irreversible pulpitis (IP). However, there are no published randomized controlled clinical trials comparing the success of supplemental buccal infiltration (BI) in mandibular first versus second molars with IP. The purpose of this prospective, randomized, double-blind study was to compare the efficacy of 4% articaine with 2% lidocaine for supplemental BIs in mandibular first versus second molars with IP after a failed inferior alveolar nerve block (IANB). This study's sample was combined with data from a previous trial.

METHODS

One hundred ninety-nine emergency subjects diagnosed with IP of a mandibular molar were selected and received an IANB with 4% articaine. Subjects who failed to achieve profound pulpal anesthesia, determined by a positive response to cold or pain upon access, randomly received 4% articaine or 2% lidocaine as a supplemental BI. Endodontic access was begun 5 minutes after infiltration. Success was defined as less than mild pain during endodontic access and instrumentation on the Heft-Parker visual analog scale.

RESULTS

There was a 25% IANB success rate with 4% articaine. The success rate for articaine supplemental BI in first molars was 61% versus 63% for second molars (P > .05). The success of lidocaine in first molars was 66%, but for second molars it was 32% (P = .004).

CONCLUSIONS

The success rate for IANB with 4% articaine was 25%. Articaine and lidocaine had similar success rates for supplemental infiltration in first molars, whereas articaine was significantly more successful for second molars. However, because BI often did not provide profound pulpal anesthesia, additional techniques including intraosseous anesthesia may still be required.

Cone-beam Computed Tomographic Study of Root Anatomy and Canal Configuration of Molars in a Spanish Population

INTRODUCTION

The aim of this study was to identify morphologic peculiarities of roots and analyze the root canal configuration in maxillary and mandibular first and second molars by means using cone-beam computed tomographic (CBCT) imaging in a Spanish population.

METHODS

A total of 284 maxillary molars and 242 mandibular molars from 112 patients were examined in vivo by CBCT imaging; only untreated molars with healthy and fully matured apices were included in this study. Details regarding the number of roots, number of canals, and root canal configuration were recorded.

RESULTS

Maxillary first and second molars had 3 roots in 97.2% and 79%, respectively. In mandibular molars, the frequency of 2 roots was 94% in first molars and 83% in second molars. The canal configuration of the palatal root was 100% Vertucci type I (1-1) in first and second molars. The distobuccal root showed a Vertucci type I configuration in 97% of first and 100% of maxillary second molars. The mesiobuccal root for first molars showed a Vertucci type II configuration (2-1) in 56.5% cases and Vertucci type IV (2-2) in 23.2%. For maxillary second molars, the Vertucci type I configuration reached 52.7%. In mandibular molars, the mesial root showed higher variability. Most frequent was the presence of 2 canals, Vertucci type II for first and second molars. In the distal root, the most common configuration was Vertucci type I in both molars.

CONCLUSIONS

The greater percentage of fused roots was observed in maxillary molars. Vertucci type II configuration was more frequent than type IV in the mesial root of mandibular molars and the mesiobuccal root of maxillary molars. A third canal in the mesial root of first mandibular molars (6.7%) was higher than expected.

Does the volume of supplemental intraligamentary injections affect the anaesthetic success rate after a failed primary inferior alveolar nerve block? A randomized-double blind clinical trial

AIM

To investigate the efficacy of 0.2 mL vs. 0.6 mL of 2% lidocaine when given as a supplementary intraligamentary injection after a failed inferior alveolar nerve block (IANB).

METHODOLOGY

Ninety-seven adult patients with symptomatic irreversible pulpits received an IANB and root canal treatment was initiated. Pain during treatment was recorded using a visual analogue scale (Heft-Parker VAS). Patients with unsuccessful anaesthesia (n = 78) randomly received intraligamentary injection of either 0.2 mL or 0.6 mL of 2% lidocaine with 1 : 80 000 epinephrine. Root canal treatment was reinitiated. Success after primary injection or supplementary injection was defined as no or mild pain (HP VAS score ≤54 mm) during access preparation and root canal instrumentation. Heart rate was monitored using a finger pulse oximeter. The anaesthetic success rates were analysed with Pearson chi-square test at 5% significance levels. The heart rate changes were analysed using t-tests.

RESULTS

The intraligamentary injections with 0.2 mL solution gave an anaesthetic success rate of 64%, whilst the 0.6 mL was successful in 84% of cases with failed primary IANB. (χ²  = 4.3, P = 0.03). There was no significant effect of the volume of intraligamentary injection on the change in heart rate.

CONCLUSIONS

Increasing the volume of intraligamentary injection improved the success rates after a failed primary anaesthetic injection.

Comparative accuracy of the Clearing Technique, CBCT and Micro-CT methods in studying the mesial root canal configuration of mandibular first molars

AIMS

To compare the accuracy of the clearing technique and cone beam computed tomography (CBCT) in the assessment of root canal configurations using micro-computed tomography (micro-CT) imaging system as the reference standard.

METHODOLOGY

Thirty-two mesial roots of mandibular first molars, selected on the basis of micro-CT scans (voxel size: 19.6 μm) and presenting several canal configurations, were evaluated using 2 CBCT scanners (voxels sizes: 120 μm and 150 μm) followed by the clearing technique. Two examiners analysed the data from each method and classified the anatomical configuration of the mesial canal according to Vertucci's system. Data were compared using Fisher's exact and chi-square tests. Reliability for each assessment was verified by the kappa test, and significance level was set at 5%.

RESULTS

Kappa value indicated a high level of agreement between the examiners. Detection of type I configurations was significantly lower in cleared teeth (P < 0.05), whilst type II root canals were detected in all specimens by both tests (P > 0.05). In mesial roots with variable anatomical configurations, CBCT and the clearing method were significantly less accurate than the reference standard (P < 0.05).

CONCLUSION

Within the tooth population studied, accuracy of identifying mesial root canal configuration was influenced greatly by the evaluation method and the type of anatomy. Detection of type I configurations in cleared teeth was significantly lower, whilst type II configurations were detected in all specimens by both methods. In mesial roots with variable anatomical configurations, neither CBCT nor clearing methods were accurate for detecting the actual root canal anatomy.

Micro-computed tomographic analysis of the root canal morphology of the distal root of mandibular first molar

INTRODUCTION

The aim of this study was to evaluate the morphologic aspects of the root canal anatomy of the distal root of a mandibular first molar using micro-computed tomographic analysis.

METHODS

One-hundred distal roots of mandibular first molars were scanned using a micro-computed tomographic device at an isotropic resolution of 19.6 μm. The percentage frequency distribution of the morphologic configuration of the root canal was performed according to the Vertucci classification system. Two-dimensional parameters (area, perimeter, roundness, aspect ratio, and major and minor diameters) and the cross-sectional shape of the root canal were analyzed in the apical third at every 1-mm interval from the main apical foramen in roots presenting Vertucci types I and II configurations (n = 79). Data were statistically compared using the Kruskal-Wallis and Dunn tests with a significance level set at 5%.

RESULTS

Seventy-six percent of the distal roots had a single root canal. Two, three, and four canals were found in 13%, 8%, and 3% of the sample, respectively. In 13 specimens, the configuration of the root canal did not fit into Vertucci's classification. Overall, 2-dimensional parameter values significantly increased at the 3-mm level (P < .05). The prevalence of oval canals was higher at the 1-mm level and decreased at the 5-mm level in which long oval and flattened canals were more prevalent.

CONCLUSIONS

The distal roots of the mandibular first molars showed a high prevalence of single root canals. The prevalence of long oval and flattened canals increased in the coronal direction. In 13% of the samples, canal configurations that were not included in Vertucci's configuration system were found.

Evaluation of isthmus prevalence, location, and types in mesial roots of mandibular molars in the Iranian Population

BACKGROUND

Management of canal isthmus is considered as an important factor for successful endodontic treatment. Accordingly, this study was designed to determine the prevalence, location, and types of isthmus in mesial root canals of extracted mandibular molars in a sample of Iranian population.

MATERIALS AND METHODS

In this cross-sectional descriptive study, 60 extracted molars with two mesial canals were included. The samples were initially decoronated and then, roots were sectioned horizontally at 2, 4, and 6 mm levels from the apex via a low-speed handpiece with a thin metallic disk and finally prepared and stained with Indian ink. All sections were examined using a stereomicroscope at a magnification of ×30. Prevalence, location, and types of isthmus were evaluated based on the classifications by Kim and Teixeira and all data were statistically analyzed by the chi-squared test. The statistical significance level was established at 0.05.

RESULTS

Eighty-three percent of extracted mandibular molars had an isthmus at the mesial root. This prevalence increased with distance from the apex, that is, 92% at 6 mm from the apex and 70% at 2 mm from the apex. A statistically significant difference was found between the sections at 2 and 6 mm from the apex (P < 0.05), but no other significant differences between other levels (P > 0.05).

CONCLUSION

Isthmus is very common in the mesial roots of the mandibular permanent molars in the Iranian population, with the highest prevalence in the 6 mm distance from the root apex. Therefore, detection, cleaning, and filling of these apical 6 mm isthmuses are of great benefit in modern endodontics.

Symmetry of root and root canal morphology of maxillary and mandibular molars in a white population: a cone-beam computed tomography study in vivo

INTRODUCTION

The aim of the present study was to use cone-beam computed tomography (CBCT) to analyze root canal anatomy and symmetry of maxillary and mandibular first and second molar teeth of a white population.

METHODS

A total of 201 patients who required CBCT examinations as part of their dental diagnosis and treatment were enrolled in the present study. Overall, 596 healthy, untreated, well-developed maxillary and mandibular molar teeth (161 maxillary first molars, 157 maxillary second molars, 117 mandibular first molars, and 161 mandibular second molars) were examined by CBCT to establish the symmetry in root and canal anatomy between right and left sides in the same patient by evaluating the number of roots and root canals and the root canal configuration.

RESULTS

Three separate roots with 3 separate canals was the normal anatomy of maxillary first and second molars. Most mandibular first and second molars had 2 separate roots, and the majority had 3 canals. In the present study, first molars, both maxillary and mandibular, exhibited greater asymmetry than the second molars. Maxillary first molars were found to be symmetrical in 71.1% of patients, whereas maxillary second molars were symmetrical in 79.6%. The remaining 28.9% and 20.4% of patients, respectively, showed asymmetry. Around 30% of the mandibular first molars and 20% of the mandibular second molars showed asymmetry.

CONCLUSIONS

The results of the present study reported a percentage of symmetry that varied from 70%-81%. These variations in symmetry should be taken in high consideration when treating 2 opposite molars in the same patient, because their anatomy may be different in up to 30% of the cases.

Successful endodontic management of hypo, meso and hypertaurodontism: Two case reports

Taurodontism is a morphoanatomical developmental anomaly rarely seen in teeth. Permanent mandibular molars are most commonly affected. Endodontic treatment of a taurodont tooth is challenging and requires special handling because of proximity and apical displacement of roots. This paper presents a successful endodontic therapy of all three types of taurodonism with two case reports - the first case with mesotaurodontism of mandibular left first molar and hypotaurodontism of mandibular left second molar and the second case with hyper taurodontism of mandibular left second molar.

A rare presentation of dens in dente in the mandibular third molar with extra oral sinus

The unusual case of dense in dente in mandibular molar area with extra oral sinus in a 30-year-old female is presented. The chief complaint of the patient was wound formation and pus discharge from the right side of lower jaw for many years. Clinical examination revealed extra oral sinus and mild swelling in vestibular region opposite the right mandibular molars. On radiographical examination, right mandibular third molar had bulbous root associated with periapical radiolucency. It appeared that there was a tooth within a tooth and the invagination extended nearly to the root apex. A clinical diagnosis of dense in dente Type III was confirmed by stereomicroscopy of ground section of the tooth. Extra oral sinus healed after extraction of the mandibular third molar within a month.