Systematic Review

Regenerative Endodontics Success Factors and their Overall Effectiveness: An Umbrella Review

Wilder J. Rojas-Gutiérrez, Eliana Pineda-Vélez, Andrés A. Agudelo-Suárez

Iranian Endodontic Journal, Vol. 17 No. 3 (2022), , Page 90-105

Introduction: Regenerative endodontics is a developing field of dentistry and aims to recover the physiological and anatomical functions of the tooth for cases of severe dental caries, pulpal pathologies and dental trauma. Materials and Methods: This umbrella review seeks to discover the scientific evidence on the effectiveness and the factors result in successful regenerative endodontic therapies in teeth with necrotic pulps and with incomplete root development. The study was conducted following the PRISMA Guidelines. There were no restrictions regarding search period. A comprehensive literature search was carried out in EMBASE, LILACS, PubMed, Cochrane, Scopus, and Google Scholar. A quality evaluation was conducted by using AMSTAR-2. A descriptive analysis of the included systematic reviews and meta-analysis were conducted. Results: Thirteen descriptive systematic reviews and 7 meta-analyses were included. Three articles evidenced low methodological quality according to AMSTAR-2 tool. Overall success rates for the endodontic regeneration procedures ranged from 50% to 98% and the survival rates were between 94% and 100%. Pulp regeneration had a high success rate, evidenced by factors such as the resolution of symptoms, healing, increased root length, dentin thickening and recovery of sensitivity. Follow-up varied from 1 to 48 months for the original studies included in the systematic reviews and meta-analyses. Conclusions: Endodontic practice offers the clinician a good treatment option in case of necrotic pulp with immature roots such as the endodontic regeneration, that is supported by high and moderate quality scientific literature.

Clinical Trial

Introduction: The aim of this blind randomized clinical study was to prospectively compare the clinical and radiographic success outcomes of calcium-enriched mixture (CEM) pulpotomy versus white mineral trioxide aggregate (WMTA) pulpotomy in permanent molars diagnosed with irreversible pulpitis. Materials and Methods: Forty patients met the inclusion criteria and agreed to join. The patients were randomly assigned into two groups: CEM pulpotomy (n=20) and WMTA pulpotomy (n=20). Clinical success was reviewed at 7 days and 3, 6 and 12 months after treatment. We organized radiographic assessment at 6 and 12 months. The data was analyzed using Chi-square, Independent t-test, and Mann-Whitney for the baseline and post-operative characteristics of the patients. Results: None of the patients were lost during recalls. Twenty-one females and 19 males participated in the study ranging between 7-14 years of age. The follow up period was extended in some of the cases for more than 1 year (12-23 month). Regarding the baseline and post-operative characteristics of the patients, there was no significant difference between the groups (P>0.05). All the cases showed clinical and radiographic success outcomes for both groups at/after12-month recall periods. There was no significant difference between the two groups clinically and radiographically (P=1). Conclusions: Based on this randomized clinical trial study, CEM and WMTA as pulpotomy agents expressed excellent clinical and radiographic outcomes with no significant difference in the treatment of permanent molars with irreversible pulpitis over a 12-month period.

Efficacy of Different Ibuprofen Formulations with Two Prescription Methods on Post Endodontic Pain of Teeth with Irreversible Pulpitis: A Randomized Clinical Trial

Saeede Zadsirjan, Ali Haeri, Elham Mohammadi, Sanaz Beiraghdar, Mohammadreza Hosseini, Soolmaz Heidari

Iranian Endodontic Journal, Vol. 17 No. 3 (2022), , Page 114-120

Introduction: Pain management during root canal therapy and after that is of great importance in endodontics. This study aimed to compare the effect of two non-steroidal anti-inflammatory drugs (NSAIDs); ibuprofen and ibuprofen lysine with two methods of prescription on pain after single-visit root canal treatment of first and second mandibular molar teeth with irreversible pulpitis. Materials and Methods: This randomized study recruited subjects experiencing moderate to severe pain from a tooth diagnosed with symptomatic irreversible pulpitis (n = 120). Subjects were randomized to receive 400 mg ibuprofen acid or 400 mg ibuprofen lysine regularly or on demand. The primary objective was to measure changes in pain scores at post-operative time frames of 6, 12, 18, 24, 48 and 72 hours after the root canal treatment on a 0-10 numerical rating scale (NRS).  Independent T-test, Non-parametric Kruskal-Wallis Test and Friedman Test were used to analyze the data. Results:  Kruskal-Wallis analysis showed a significant difference in NRS score between on-demand ibuprofen group and regular ibuprofen group and also between regular ibuprofen lysine group and regular ibuprofen group at 6 hours after the treatment (P<0.05). But no remarkable difference was observed in the recorded mean pain intensity of four study groups in the other time frames (P>0.05). Conclusions: Based on this randomized clinical trial, there was no significant difference in the pain intensity of patients using ibuprofen and ibuprofen lysine. Additionally, there was no significant difference in the degree of pain between the on-demand and regular groups, despite the fact that patients in the on-demand group used less medications. Due to the multiple negative effects of NSAIDs, it would be wise to prescribe ibuprofen on demand.

Review Article

Evaluation of the Levels of Evidence in Three Clinical Chapters in Five Editions of the Textbook Pathways of the Pulp

Nima Hatami, Arash Shahravan, Marzieh Rouzpeykar, Amir Hossein Nekouei, Maryam Sharifi

Iranian Endodontic Journal, Vol. 17 No. 3 (2022), , Page 121-125

Introduction: The levels of evidence (LOE) of dental education texts is critical from the educational point of view. The present study aimed to evaluate the levels of evidence of references used in three clinical chapters in the textbook Pathways of the Pulp. Material & Method: The references of three clinical chapters in the text book Pathways of the Pulp were assessed in five of its editions. The levels of evidence were ranked according to study type and the Oxford scale from 0 to 5. The chi-square test was used to compare the level of evidence between different editions of the "Retreatment," "Trauma," and "Surgery" chapters. Results: A total of 3656 references were reviewed and analyzed from the "Trauma" (928 references), "Re-treatment" (1906 references), and "Surgery" (822 references) chapters in the 1998, 2002, 2006, 2011, and 2016 editions. The percentage of the LOE 0 (no evidence) was high (>60%) in all three chapters in all editions (P<0.001). The levels of evidence had the same distribution in all editions (P=0.871). The LOE of the "Re-treatment" (P=0.044) and "Surgery" (P<0.001) chapters changed in some editions. Conclusion: The majority of references in the three clinical chapters of the book are low-level evidence. Encouragement policies for researchers to conduct studies with high LOE are necessary.

Original Article

Dentine Thickness of Second Mesiobuccal Canals in First Maxillary Molars Prepared with Rotary Instruments

Maryam Forghani, Ali Hamedi, Monireh Khorasani, Siavash Moushekhian, Nasir Kheirabadi

Iranian Endodontic Journal, Vol. 17 No. 3 (2022), , Page 126-131

Introduction: The purpose of this study was to evaluate the thickness of the remaining dentine wall in the danger zone of the second mesiobuccal (MB2) canals using cone-beam computed tomography (CBCT) in maxillary first molars following preparation by means of HERO 642 rotary instruments with different tapers. Methods and Materials: The study samples included twenty-five mesiobuccal roots of maxillary first molars. A two-step method was employed to prepare the MB2 canals applying HERO 642 instruments: using a 0.02 taper (step 1), and a 0.04 taper (step 2). The roots were scanned before preparation, and after each step. The thickness of the dentine wall was recorded at the CEJ level, as well as 2 mm and 4 mm below the CEJ. The repeated-measures ANOVA in conjunction with the Cochran tests were used to compare the changes in the thickness of the root canal wall. Results: There was no area with dentine thickness of <0.5 mm before preparation. A significant reduction in dentine thickness occurred following the preparation with both 0.02 and 0.04 files at all three levels compared with the pre-instrumentation values (P< 0.05). However, areas with dentine thickness of < 0.5 mm after preparation using 0.04 files were significantly more than those resulting from the application of 0.02 files both at the CEJ and 2 mm-below-CEJ points, but the differences were not significant at the 4mm-below-CEJ level. Conclusion: Within the limitations of the present in vitro study, the use of larger taper instruments in MB2 root canals of maxillary first molars increased the quantity of samples with dentine thickness less than 0.5 millimeter at the coronal level of the root canal. It was concluded that instruments with large tapers, should be used with caution in troughing or preparing such root canals to reduce the risk of strip perforation.

Effect of A Clinical-Replicable Cooling Protocol on the Cyclic Fatigue Resistance of Heat-Treated Nickel-Titanium Instruments

Luana Heck, Theodoro Weissheimer, Pedro Henrique Souza Calefi, Murilo Priori Alcalde, Rodrigo Ricci Vivan, Ricardo Abreu da Rosa, Marco Antonio Hungaro Duarte, Marcus Vinicius Reis Só

Iranian Endodontic Journal, Vol. 17 No. 3 (2022), , Page 132-137

Introduction: The aim of this study was to evaluate the bending and cyclic fatigue resistance of Wave One Gold (WOG) and X1 Blue (X1B) instruments when tested at body temperature (36° ± 1°C) subjected or not to an alloy cooling protocol.

Methods and Materials: Twenty instruments of each system (n=40) were selected and divided into two groups: body temperature (BT); body temperature with cooling protocol (CP). Cyclic fatigue test was performed until fracture in a custom stainless-steel device with water bath equipment to simulate body temperature. CP group instruments were subjected to 5 seconds of spray cooling at every 30 seconds. Time to fracture was recorded. Resistance to bending at 45o was evaluated using ten instruments of each system. Fractured surfaces were examined under scanning electron microscopy (SEM). Statistical analysis was performed using Student t test at 5% significance level.

Results: WOG instruments had significantly less cyclic fatigue resistance compared to X1B instruments in BT (P=0.00001) and CP (P=0.0001) groups. Significantly increased resistance was observed in X1B instruments (P=0.0003) and in WOG (P=0.0003) when cooling protocol was applied. There were no significant differences between the values of resistance increase presented by the instruments after cooling (P>0.05). Bending test presented no statistically significant differences between the tested instruments (P>0.05). Both instruments in both groups showed typical features of cyclic fatigue behavior under SEM.

Conclusions: Cooling protocol extended the cyclic fatigue resistance of both instruments.

Introduction: This study investigated the amount of debris and smear layer remaining followed chemomechanical preparation using three systems: ProTaper Universal, reciprocating SafeSider, and hand K-Flexofiles with scanning electron microscope (SEM). Materials and Methods: Sixty-five mandibular molars with mesiobuccal canal curvature (25 to 40°) were extracted and divided into one control group (n=5), and three experimental groups (n=20) according to the preparation method; K-Flexofile, ProTaper Universal and SafeSider instruments. All canals were irrigated with 3 ml of 5.25% sodium hypochlorite solution and 3 mL of 17% EDTA. Subsequently, the canals were irrigated with 5 ml of normal saline. Then the teeth were examined under the scanning electron microscope (SEM). Kruskal-Wallis, Dunn-Q Bonferroni, and Friedman tests were used for statistical analysis of results. Results: To assess the accumulation of debris, statistically significant differences were observed only in the coronal area among ProTaper Universal, SafeSider, K-Flexofile, and the control group. (P=0.029). To evaluate the residual smear layer amount, statistically significant differences were observed only in the coronal and middle areas, following the preparation of the canals using ProTaper Universal, SafeSider, and hand K-Flexofiles and control groups (P=0.019). Conclusions: Based on the present in vitro study, we can declare that the canals were utterly cleaned of debris and smear layer in none of the groups. Manual Flexofile and ProTaper Universal groups result in cleaner canal walls than reciprocal SafeSider, in the coronal and middle thirds.

Case Report

Regenerative Endodontic Treatment of a Traumatized Immature Necrotic Permanent Incisor: A Case Report

Marisa Nogueira Alencar, Tatiana Carvalho Kowaltschuk , Alexandre Kowalczuck , Everdan Carneiro , Ulisses Xavier da Silva Neto, Vânia Portela Ditzel Westphalen

Iranian Endodontic Journal, Vol. 17 No. 3 (2022), , Page 146-150

The current case report documents the clinical approach adopted for a traumatized immature necrotic permanent upper left central incisor after a bike accident. The treatment involved regenerative endodontic procedures (REPs) using “High Plasticity Mineral Trioxide Aggregate” (MTA Repair HP) as a cervical barrier over blood clot. The preservation included three years of follow-up appointments of clinical evaluations and periapical digital radiographs. Cone beam computer tomography (CBCT) was taken at six and thirty-six months for the evaluation of root development.

Conservative Management of Periapical Cementoblastoma: A Case Report

Mojgan Feli , Anita Taheri , Pooya Raeesi , Fatemeh Mashhadi Abbas , Mostafa Alam

Iranian Endodontic Journal, Vol. 17 No. 3 (2022), , Page 151-155

As a rare ectomesenchymal neoplasm, benign cementoblastoma comprises less than 6% of all odontogenic tumors. The typical treatment plan involves surgical excision and extraction of the affected tooth. Limited evidence, however, suggests the conservative management of this condition as the best treatment. This article discusses the case of a 32-year-old man who had benign cementoblastoma and underwent conservative treatment. The diagnosis was established based on clinical and radiological features analyses. Root canal therapy was performed on the tooth, followed by enucleation, curettage, apicoectomy, and guided bone regeneration (GBR) 30 days later. After a year of follow-up, there was no recurrence, and the tooth was in healthy conditions. These findings demonstrated that the tooth affected by cementoblastoma can be saved. It was treated conservatively to preserve the patient’s oral health and masticatory function.

Connective tissues in lateral canals mostly remain vital even after pulp necrosis of the main canals. However, lateral canals may become necrotic following the pulp necrosis of the main root canal or after root canal therapy. This case report presents a maxillary central incisor with a necrotic lateral canal and a sinus tract that initially showed healing following the primary endodontic treatment but showed infection after fiber-post placement and permanent restoration with composite resin. Tracing the sinus tract did not reveal the reason for the infection; however, cone beam computed tomography (CBCT) confirmed a lateral radiolucency of the maxillary right central incisor as the only reason for the return of the infection. A conservative re-treatment approach was performed, replacing the fiber post with gutta-percha and root canal sealer. Successful outcome was achieved with a conservative approach; however, it took some time for the sinus tract to heal. In the case of lateral canal infection, sealing the main root canal space could heal the lesion even without lateral canal negotiation. If the main root canal seal is disturbed, re-cleaning and obturating the main root canal could be successful

Maintaining a Hopeless Traumatized Maxillary Central Incisor as a Transient Treatment Option: A Case Report with a 3-Years Follow-Up

Yasamin Ghahramani, Fariborz Moazami, Yasser Samadi, fateme eskandari

Iranian Endodontic Journal, Vol. 17 No. 3 (2022), , Page 161-164

An open apices tooth is among the rare types of traumatic dental injuries is horizontal root fracture. Many factors may affect the treatment and prognosis of root fractures, like the time between trauma and treatment, degree of dislocation and mobility, stage of tooth development, fracture site, and patient’s age. This case presents a horizontal root fracture of a maxillary central incisor in an 8-year-old boy. The tooth was considered for extraction due to excessive mobility and deep probing depth, but the patient’s parents refused to extract the tooth. After one year, during the follow-up examination, we noticed an unprecedented healing process had been initiated. Due to the weak crown-to-root ratio, the traumatized tooth was splinted to the surrounding teeth to reduce the wrecking forces and promote healing. In a three-year follow-up, the cone-beam computed tomography examination showed that the coronal and apical fragments continued to develop separately. Also, it was observed that the mobility and probing depth were reduced significantly.