Regenerative Endodontic Protocols Research Articles

A survey on awareness and knowledge among dentist practicing regenerative endodontics towards current regenerative endodontic protocols and the scaffolds used in regenerative dentistry

There are many inconsistencies in the protocols followed for Regenerative Endodontic Procedures (REP’s).This study was formulated with an aim to conduct a survey among Pediatric Dentists, Endodontists and General Practioners treating Necrotic young permanent teeth to examine their awareness and Knowledge on Current Regenerative Endodontic Protocols and Scaffolds used in regenerative dentistry. MethodsA Cross-Sectional Survey was carried out amongst 100 Pediatric dentists,100 Endodontists and 100 General Practioners. It was web-based survey and the questionnaire was formulated and all the items in the questionnaire were tested for reliability and validity before circulation of the questionnaire for the purpose of the study. ResultsThe results of the study indicated that all the three groups were unaware that failure of cases should be reported to AEE (American Academy of Endodontics) REP Database and only 20.2, 20.1 and 0.3 % of Pediatric dentists,Endodontists and General Dentists preferred Regenerative Dentistry as a clinical protocol for REP. With respect to knowledge regarding irrigation and disinfection procedures all three groups were lacking in the knowledge regarding intracanal medicament for disinfection and the irrigation solutions. ConclusionThere is a lack of homogeneity in protocols followed for REP among those practicing Regenerative Endodontics as a protocol. Since it’s an evolving science there is a need to bring about a uniformity in practices to increase the evidences to support the causal effect relation of regenerative endodontics.

Endodontic Regenerative Procedures in Necrotic Adult Teeth

There have been published regenerative endodontic protocols for treating immature teeth in young patients, but there are no clinical considerations for the adult teeth. The goal of the present review is to propose a specific clinical protocol for both mature and immature adult teeth with necrotic pulps. Research was performed from January to April of 2021. From the 539 studies identified through the initial search, 23 studies were qualified for the final analysis (3 randomized controlled trials and 20 case reports). The results in mature adult teeth indicate a success rate of 96.35 and 100% in bone healing through the randomized controlled trials and case reports, respectively; 100% in absence of clinical symptoms, and 58 and 62.5% in positive response to sensibility tests. The success rate in the case reports in teeth with open apex reported a 61.5% of root development, 100% of bone healing, 96.15% of absence of clinical symptoms, and 43.7% of positive response to sensibility tests. The current evidence is scarce but emerging, so REPs may be a promising alternative for treating adult necrotic teeth. The clinical protocol proposed is based on the evidence available and age considerations, and should be updated in the future.

Molecular Biological Comparison of Dental Pulp- and Apical Papilla-Derived Stem Cells

Both the dental pulp and the apical papilla represent a promising source of mesenchymal stem cells for regenerative endodontic protocols. The aim of this study was to outline molecular biological conformities and differences between dental pulp stem cells (DPSC) and stem cells from the apical papilla (SCAP). Thus, cells were isolated from the pulp and the apical papilla of an extracted molar and analyzed for mesenchymal stem cell markers as well as multi-lineage differentiation. During induced osteogenic differentiation, viability, proliferation, and wound healing assays were performed, and secreted signaling molecules were quantified by enzyme-linked immunosorbent assays (ELISA). Transcriptome-wide gene expression was profiled by microarrays and validated by quantitative reverse transcription PCR (qRT-PCR). Gene regulation was evaluated in the context of culture parameters and functionality. Both cell types expressed mesenchymal stem cell markers and were able to enter various lineages. DPSC and SCAP showed no significant differences in cell viability, proliferation, or migration; however, variations were observed in the profile of secreted molecules. Transcriptome analysis revealed the most significant gene regulation during the differentiation period, and 13 biomarkers were identified whose regulation was essential for both cell types. DPSC and SCAP share many features and their differentiation follows similar patterns. From a molecular biological perspective, both seem to be equally suitable for dental pulp tissue engineering.

Void characteristics and tortuosity of calcium silicate-based cements for regenerative endodontics: a micro-computed tomography analysis

BackgroundInternal voids of materials can serve a hub for microorganism and affect the sealing ability. This study aimed to evaluate the sealing performance of calcium silicate-based cements in immature teeth treated with regenerative endodontics.MethodsTwenty single root canals from immature permanent premolars were prepared using regenerative endodontic protocols. The root canals were randomly divided into two groups and sealed with mineral trioxide aggregate (MTA) and Biodentine (BD). The teeth were kept in humid environment for 7 days and scanned using micro-computed tomography. The voids within the cements were segmented and visualized using image processing, incorporating the modified Otsu algorithm. The porosity of each sample was also calculated as the ratio between the number of voxels of voids and the volume of the cements. Tortuosity was also calculated using the A-star algorithm.ResultsVoids larger than 70 μm were predominantly observed in the top and interfacial surface of cements. The others were evenly distributed. MTA and BD showed the same level of porosity and tortuosity at interfacial surfaces. In inner surfaces, MTA showed more less porosity and tortuosity compared to BD (p < 0.05).ConclusionsThere were no differences in sealing performance between MTA and BD.

REPETITIVE REGENERATIVE ENDODONTIC PROTOCOL TREATMENT FOR MATURE TEETH WITH DENS INVAGINATUS AND SEVERE PERFORATED INTERNAL ROOT RESORPTION: A CASE REPORT WITH 24-MONTH FOLLOW-UP

The association of internal root resorption (IRR) with dens invaginatus is an extremely rare finding, and its incidence may be underestimated, adding to the difficulty of endodontic treatment. A 9-year-old boy was admitted with complaints of swelling and pain. Radiological examination revealed closed apex Oehlers type II dens invaginatus and severe IRR, as well as apical third of two lateral root perforation and lesion. Calcium hydroxide applied in the regenerative endodontic protocol (REP) as intracanal medicament. Differently, bleeding was achieved by irritating the lateral perforation area. However, the tooth showed spontaneous pain and sensitivity to percussion after 2 months. The same REP was performed, but a triple antibiotic paste was used as the intracanal medicament. After 2 years, the tooth was asymptomatic, and radiographic examination revealed the decrease was cared on the previous resorption sites, and one of the openings on the lateral root surface had closed.

Regenerative endodontics model in immature infected rat molars using two step protocol

Aim: to develop a model for regenerative endodontics using newly-weaned Wistar rats immature molars with pulp necrosis to histologically describe the evolution of apical tissues following treatment with a bi-antibiotic paste, induced bloodclot formation and MTA. Methods: Ten 25-day-old female Wistar rats were divided into an initial control group (Ci) and two experimental groups in which pulp necrosis was experimentally induced on the left mandibular first molar by exposing the pulp chamber and leaving it open to the oral environment. One of the experimental groups was left untreated (E1) while the other was submitted to a protocol of regenerative endodontics 10 days thereafter (E2). Fifteen days after placement of a bi-antibiotic paste, bleeding was induced into the root canal space and MTA was placed upon. Animals were euthanized 30 days later. Right mandibular first molars served as an 80-day-old final control group (Cf). Each hemimandible was histologically processed to analyse parameters associated with root development. Statistical analysis was carried by means of ANOVA; p values below 0.05 were considered statistically significant. Results: baseline (i.e. 25-days old) mean root length and apical diameter of the distal root canal were 1.84±0.25 and 0.38±0.02mm respectively. Following the regenerative endodontic protocol, cells lining the walls of the root canal and significant increase to both length (2.37±0.22mm) and diameter (0.32±0.03 mm) were observed. Conclusions: newly-weaned Wistar rats serve as a suitable model to evaluate regenerative endodontic protocols. However, further research is needed in order to disclose the nature of the cells and/or cell mediators involved.

Different Approaches to the Regeneration of Dental Tissues in Regenerative Endodontics

(1) Background: The regenerative procedure has established a new approach to root canal therapy, to preserve the vital pulp of the tooth. This present review aimed to describe and sum up the different approaches to regenerative endodontic treatment conducted in the last 10 years; (2) Methods: A literature search was performed in the PubMed and Cochrane Library electronic databases, supplemented by a manual search. The search strategy included the following terms: “regenerative endodontic protocol”, “regenerative endodontic treatment”, and “regenerative endodontics” combined with “pulp revascularization”. Only studies on humans, published in the last 10 years and written in English were included; (3) Results: Three hundred and eighty-six potentially significant articles were identified. After exclusion of duplicates, and meticulous analysis, 36 case reports were selected; (4) Conclusions: The pulp revascularization procedure may bring a favorable outcome, however, the prognosis of regenerative endodontics (RET) is unpredictable. Permanent immature teeth showed greater potential for positive outcomes after the regenerative procedure. Further controlled clinical studies are required to fully understand the process of the dentin–pulp complex regeneration, and the predictability of the procedure.

Maturogenesis: A novel concept based on regeneration for peadatric patients

The problems encountered while treating immature, necrotic teeth has led to a shift in the treatment protocol. The biologically-based principles and regenerative endodontic protocols replacing the traditional methods. Preliminary research suggests that Revascularization has emerged as such an alternative. The stem and progenitor cells from the pulp and? or periodontium lead to root development. The aim of this paper is to accomplish a literature review concerning this novel concept. Keywords: Maturogenesis, Regeneration, Immature Teeth, Revascularization, Revitalization.

Nonsurgical Retreatment Using Regenerative Endodontic Protocols: A Case Report

The aim of this case report was to describe regenerative endodontic procedures (REPs) of the previously treated mature teeth with long-term results. Regenerative endodontic procedures are aimed to treat apical periodontitis and regenerate the pulp-dentin complex in necrotic teeth. However, there is no consensus in using REPs in the previously treated mature teeth. The aim of this case report was to describe REPs of the previously treated mature teeth with long-term results. A 25-year-old woman presented pain on chewing on 15 and swelling (WHO numbering system). The tooth had been endodontically treated and restored 4 years ago. After removing the old root canal filing, the roots were irrigated with 2.5% sodium hypochlorite and 17% EDTA using sonic activation. Calcium hydroxide (CH) was used as medicament for 3 weeks. At the second visit, CH was removed, and canals were irrigated as like as the first visit. Apical bleeding was induced, and concentrated growth factors (CGFs) were placed inside the root canal. The tooth has been followed up to 3 years. The tooth was functional and asymptomatic at the recall visits. Since the first-year follow-up, the tooth responded to the electric pulp test and the thermal test. Radiological examinations revealed healing of apical lesion and hard tissue deposition. Regenerative endodontic procedures can offer an advantage over traditional endodontic procedures in terms of tertiary healing, with a predictable, user-friendly procedure also for retreatment cases.

A comparison of two pulp revascularization techniques using platelet-rich plasma and whole blood clot.

Aim:The aim of this preliminary study was to compare outcomes of two regenerative endodontic protocols in necrotic teeth with open apices.Methodology:Forty teeth with open apices in patients with an age range of 15-54 were randomly distributed in two groups: group 1, with whole blood clot in the canal (n=20) and group 2, whole blood with Platelet rich plasma (PRP) in the canal (n=20). Clinical and radiological follow up assessments were undertaken over a period ranging from 6 months to one year. Radiographic Root Area (RRA) was measured using the freeware ImageJ. Statistical analysis was performed using the independent samples t test and the Chi-squared test, the significance level was set at p=0.05.Results:There was no difference in the percentage change in RRA between the PRP group and whole blood-clot + PRP group.Conclusion:Whole blood clot and PRP are comparable on the grounds of percentage change in RRA and there is no statistically significant difference between the two in a follow-up period of up to one year.

Fracture resistance of simulated immature teeth treated with a regenerative endodontic protocol

This study aims to evaluate fracture resistance of simulated immature teeth after treatment with regenerative endodontic procedure (REP) using tricalcium silicate cements (TSCs) as cervical plugs. Bovine incisors were sectioned to standard crown/root ratio. Pulp tissue was removed and canals were enlarged to a standardized diameter. Teeth were then treated with a REP protocol consisting of NaOCl and EDTA irrigation, intracanal medication with triple-antibiotic paste for 14 days followed by a TSC cervical seal and composite restoration. Teeth were divided into groups according to the material used; Mineral-Trioxide-Aggregate (MTA), Biodentine, TotalFill. Teeth filled with guttapercha (GP) and intact teeth served as controls. All teeth subjected to an increasing compressive force (rate of 0.05 mm/s at a 45° angle to the long axis of the tooth) until fracture. All treated teeth exhibited significantly lower resistance to fracture compared to the intact teeth but no difference was found between the TSC groups (Kruskal-Wallis, Dunn’s multiple comparison, p < .05). TSCs applied at the cervical area of simulated immature teeth treated with REP did not reinforce fracture resistance.

Management of an Immature Necrotic Permanent Molar with Apical Periodontitis Treated by Regenerative Endodontic Protocol Using Calcium Hydroxide and MM-MTA: A Case Report with Two Years Follow Up

Traditionally, immature teeth diagnosed with necrotic pulp and periapical periodontitis were treated by apexification with long-term calcium hydroxide or in one session with mineral trioxide aggregate (MTA) or Biodentine apical plug. However, these teeth become fragile and susceptible to root fracture. Regenerative endodontic procedure is a new therapeutic approach that promotes continuation of root growth in immature necrotic teeth potentially preventing root fracture. Only few case reports have shown the success of this procedure on molar cases. The current case report demonstrates a regeneration of a lower first molar with necrotic pulp and chronic apical abscess treated with Micro Mega-MTA (MM-MTA), a new endodontic biomaterial that has not been described previously. Calcium hydroxide was used as an intracanal medicament for two weeks. Next, calcium hydroxide was removed and after blood clot creation, MM-MTA® was placed over it. Apical healing and continuation of root growth were evident at nine months follow-up. CBCT at two years follow-up confirmed apical closure and complete healing. This case shows that a regenerative endodontic procedure for management of an immature necrotic permanent molar is feasible and can be successfully done using Ca(OH)2 and MM-MTA.

Regenerative Endodontics: Burning Questions

Pulp regeneration and its clinical translation into regenerative endodontic procedures are receiving increasing research attention, leading to significant growth of the published scientific and clinical literature within these areas. Development of research strategies, which consider patient-, clinician-, and scientist-based outcomes, will allow greater focus on key research questions driving more rapid clinical translation. Three key areas of focus for these research questions should include cells, signaling, and infection/inflammation. A translational pathway is envisaged in which clinical approaches are increasingly refined to provide regenerative endodontic protocols that are based on a robust understanding of the physiological processes and events responsible for the normal secretion, structure, and biological behavior of pulpal tissue.

EVALUATION OF MATUROGENESIS AND APEXIFICATION TECHNIQUES IN THE MANAGEMENT OF TRAUMATIZED NON-VITAL IMMATURE PERMANENT INCISORS

Introduction: Regenerative endodontics is a promising alternative treatment for immature teeth with necrotic pulps. Aim of the study: The present study was performed to assess healing potential of young permanent immature teeth with necrotic pulp after the following treatment protocols: (1) Calcium hydroxide apexification, (2) the regenerative endodontic protocol (blood clot scaffold). Materials and Methods: Immature necrotic permanent maxillary central incisors (n = 48) were divided into 2 groups according to the treatment protocol: the apexification group (calcium hydroxide), the REG group (regenerative endodontic protocol). Follow-up was done up to 18 months. Standardized radiographs were digitally evaluated for an increase in root length and thickness, a decrease in the apical diameter Follow-up was done up to 18 months. Results: After a follow-up period of 18 months, most of the cases showed radiographic evidence of periapical healing. Groups showed a progressive increase in root length and width and a decrease in apical diameter. Conclusions: The regenerative endodontic procedure allowed the continued development of roots in teeth with necrotic pulps.

Disinfection Efficacy of Current Regenerative Endodontic Protocols in Simulated Necrotic Immature Permanent Teeth

IntroductionThe lack of mechanical debridement and reduced concentrations suggested for chemical debridement to maintain stem cell viability call into question the disinfection efficacy of current regenerative protocols. Current protocols vary in the concentration and type of antibiotic medicaments used. The aim of this study was to determine if simulated immature teeth infected with Enterococcus faecalis can be completely disinfected by following current standardized regenerative protocols and to evaluate the probable effects of residual bacteria on stem cell toxicity. MethodsSixty-eight caries-free maxillary incisors were used. S1 sampling protocols were validated in both negative and positive control groups via culture, scanning electron microscopy, and confocal laser scanning microscopy. All teeth, except the negative controls, were inoculated with E. faecalis. The teeth were divided into the following groups: group 1, triple antibiotic paste (ciprofloxacin:metronidazole:minocycline) at concentrations of 10, 1, and 0.1 mg/mL; group 2, double antibiotic paste (ciprofloxacin:metronidazole) at concentrations of 10, 1, and 0.1 mg/mL; group 3: Ultracal XS calcium hydroxide (Ultradent, St Louis, MO); and controls, negative and positive controls. Current regenerative protocols recommended by the American Association of Endodontists were followed. S2 sampling was performed after 4 weeks and tested for bacterial presence via culturing, scanning electron microscopy, and confocal laser scanning microscopic analysis. ResultsThe data showed that calcium hydroxide and the current recommended antibiotic concentrations are not capable of completely eliminating bacteria from simulated necrotic immature permanent teeth. ConclusionsOverall, this study focuses on the need to re-evaluate the balance between stem cell toxicity and bacterial elimination in order to determine the appropriate concentrations and medicaments for successful regenerative endodontic procedures.

Attachment and proliferation of dental pulp stem cells on dentine treated with different regenerative endodontic protocols.

To investigate the attachment and proliferation of dental pulp stem cells (DPSC) on dentine treated with various endodontic regeneration protocols. Standardized dentine samples were irrigated with sodium hypochlorite (1.5% NaOCl) and ethylenediaminetetraacetic acid (17% EDTA) and randomized into four treatment groups and two control groups. The treatment groups were treated with a clinically used concentration of triple antibiotic paste (TAP), double antibiotic paste (DAP), calcium hydroxide (Ca(OH)2 ) or diluted TAP in a methylcellulose system (DTAP) for 1week. Each sample in the treatment groups was then irrigated with EDTA. The two control groups were treated with EDTA or received no treatment. Dental pulp stem cells were seeded on each dentine specimen (10000 cells). Lactate dehydrogenase activity assays were then performed to evaluate the attached DPSC after 1day of incubation. Water-soluble tetrazolium assays were used to determine DPSC proliferation after three additional days of incubation. Friedman's test followed by least significant difference were used for statistical analyses (α=0.05). Triple antibiotic paste and DTAP regeneration protocols, as well as EDTA-treated dentine, caused significant increases in DPSC attachment to dentine. Triple antibiotic paste, DAP and Ca(OH)2 regeneration protocols caused significant reductions in DPSC proliferation on dentine. However, the DTAP regeneration protocol did not haveany significant negative effects on DPSC proliferation. The clinically used endodontic regeneration protocols that include the use of TAP, DAP or Ca(OH)2 medicament negatively affected DPSC proliferation on dentine. However, the use of DTAP medicament during regenerative endodontic treatment may not adversely affect the proliferation of DPSC.

Revascularization of Necrotic Immature Permanent Teeth: An Update

ABSTRACT In the recent years, there is a paradigm shift in the management of necrotic immature permanent teeth, with most of these teeth being treated by revascularization rather than conventional apexification procedure. Current regenerative endodontic protocols (REP) emphasizes the need to have a disinfection protocols that will enable good disinfection without causing damage to stem cells. The current available evidence suggest that true pulp-dentin complex is not being formed after REP, nevertheless it can result in continued root development that will enable such tooth to survive for a long time. This article highlights the recent trends in revascularization procedures. How to cite this article Velmurugan N. Revascularization of Necrotic Immature Permanent Teeth: An Update. J Oper Dent Endod 2016;1(1):18-24.

Regenerative Potential of Immature Permanent Teeth with Necrotic Pulps after Different Regenerative Protocols

IntroductionRegenerative endodontics is a promising alternative treatment for immature teeth with necrotic pulps. The present study was performed to assess the regenerative potential of young permanent immature teeth with necrotic pulp after the following treatment protocols: (1) a mineral trioxide aggregate (MTA) apical plug, (2) the regenerative endodontic protocol (blood clot scaffold), and (3) the regenerative endodontic protocol with a blood clot and an injectable scaffold impregnated with basic fibroblast growth factor. MethodsImmature necrotic permanent maxillary central incisors (n = 36) of patients 9–13 years old were divided into 3 groups according to the treatment protocol: the MTA group (MTA apical plug), the REG group (regenerative endodontic protocol [blood clot]), and the FGF group (regenerative endodontic protocol [blood clot + injectable scaffold]). Follow-up was done up to 18 months. Standardized radiographs were digitally evaluated for an increase in root length and thickness, a decrease in the apical diameter, and a change in periapical bone density. ResultsAfter a follow-up period of 18 months, most of the cases showed radiographic evidence of periapical healing. Groups 2 and 3 showed a progressive increase in root length and width and a decrease in apical diameter. ConclusionsThe regenerative endodontic procedure allowed the continued development of roots in teeth with necrotic pulps. The use of artificial hydrogel scaffold and basic fibroblast growth factor was not essential for repair.

Is Pulp Regeneration Necessary for Root Maturation?

IntroductionTrue regeneration of the dental pulp-dentin complex in immature teeth with necrotic pulps has not been shown histologically. It is not known to what extent this true tissue regeneration is necessary to achieve clinically acceptable outcomes. MethodsThis case report describes the treatment of a patient with an immature maxillary right central incisor with a history of impact trauma and enamel-dentin crown fracture. A diagnosis of pulp necrosis with acute apical abscess was established. A regenerative endodontic protocol that used a paste containing Augmentin for 5 weeks as an intracanal medicament was used. ResultsFollow-ups at 9, 12, 17, and 31 months revealed complete osseous healing of the periapical lesion and formation of the root apex, but without increase in root length. Clinically, the tooth was functional, asymptomatic, and nonresponsive to pulp vitality tests. The crown discolored over time. On reentering the root canal, no tissues were observed under magnification inside the root canal space. The root canal treatment was completed with mineral trioxide aggregate obturation. ConclusionsAugmentin might be an acceptable choice for root canal disinfection in regenerative endodontic procedures. The protocol for regenerative endodontic treatment is not predictable for pulp-dentin regeneration. Formation of the root apex is possible without pulp regeneration.

Revascularization of immature permanent teeth with apical periodontitis

The aim of this minireview was to identify and review the scientific evidence regarding regenerative endodontic protocols claiming to revascularize permanent immature teeth with apical periodontitis. The literature was identified using the PubMed/MEDLINE, Scopus, Scirus, EMBASE and Cochrane databases up to February 2013. Studies were selected independently by two different researchers (kappa index: 0.88), based on established inclusion/exclusion criteria. The methodological quality of the reviewed papers was classified as high, medium or low (HQ, MQ, LQ). The search strategy identified 285 titles. Nine studies, both human and animal based, were selected after application of the criteria (LQ:5; MQ:4). In most of these studies (seven of nine), the revascularization protocol included a triple antibiotic combination as canal disinfectant for a period of 1-4 weeks after blood clot formation (LQ:5; MQ:4), although there is no clear consensus about the treatment protocol. Two studies reported tooth discoloration after the revascularization process (LQ:2), and only three (LQ:1; MQ:2) reported a success rate of 54.9% in dogs and 73.6% and 80% in humans, respectively. Revascularization of immature permanent teeth with apical periodontitis is possible and preferable to apexification. Nevertheless, there is a widespread lack of randomized clinical trials and blinded measures. In addition, the small sample sizes that are common in these studies as well as the generally low quality of the analysed publications require the results to be viewed with caution. There is a high risk of bias, with a low quality of available information, for developing clinical guidelines for regenerative endodontic protocols; rigorous randomized clinical trials are therefore needed.