In vitro evaluation of the antimicrobial effects of different intracanal medications in necrotic immature teeth

Pulp regeneration treatment using different bioactive materials in permanent teeth of pediatric subjects

Background and Objectives

The present systematic review aims to assess the success rate of the pulp regeneration treatment, according to the American Association of Endodontists (AAE) criteria, using different bioactive materials in permanent teeth of pediatric subjects (6-17 years of age).

Materials and Methods

The study protocol was registered on PROSPERO and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. The question formulation was accomplished using the PICO model, and an electronic search was carried out on Scopus, MEDLINE/PubMed, Web of Science, and Cochrane databases till April 1, 2023. A total of 30 studies were established to fulfill the inclusion criteria of this systematic review.

Results

A total of 273 teeth have been treated with pulp regeneration treatment. By comparing different biomaterials and the success criteria defined by the AAE, the material associated with a higher success rate was found to be the white mineral trioxide aggregate. However, the overall success rate of pulp regeneration treatment was reported for 248 out of 273 teeth (91.20%).

Conclusions

Data obtained support the potential that regenerative endodontics aids in continuing root development in permanent immature teeth. Further studies are needed for a more extensive evaluation of the use of different biomaterials and the success rate in regenerative endodontics.

Unlocking the Potential of Cellular Guidance in Endodontics: Advancing the Process of Pulp Regeneration and Beyond

Regenerative endodontics represents a paradigm shift in dental therapy, with the potential to not only restore damaged dental tissues but also to preserve the vitality of teeth. At the heart of this innovative approach is cell homing, a technique that harnesses the body's own healing mechanisms by recruiting endogenous stem cells to the site of dental injury for effective tissue regeneration. This review delves into the intricate processes of cell homing in the context of regenerative endodontics, particularly focusing on its application in immature teeth with open apices. It examines the role of bioactive molecules, scaffolds, and growth factors in orchestrating cell migration and differentiation within the root canal space. In addition, the review addresses the current limitations in clinical practice, such as the challenges in completely regenerating the pulp-dentin complex and the unpredictability in long-term outcomes. It also explores future possibilities, including the potential for more refined and effective regenerative strategies. By providing a comprehensive overview of the current state of cell homing in regenerative endodontics, this article aims to contribute to the ongoing development of advanced therapeutic techniques that could revolutionize endodontic treatment and improve patient care.

Efficacy of disinfection procedures performed prior to regenerative endodontic therapy: An integrative review

The aim of this integrative review was to identify whether the disinfection procedures performed prior to regenerative endodontic treatment were effective on biofilm removal from the root canals. The research was based on PubMed, Latin American and Caribbean Health Sciences Literature (Lilacs) and Scientific Electronic Library Online (SciELO) databases. Four articles were selected; one of the studies was in vivo and the others ex vivo. Different disinfection procedures were studied, characterised mainly by the use of intracanal medication, highlighting the double antibiotic paste, triple antibiotic paste and calcium hydroxide paste. Disinfection ability was evaluated against Enterococcus faecalis and multispecies biofilms by using the fluorescence technique and colony forming unit counting, for 7 to 21 days. Double antibiotic paste and triple antibiotic paste demonstrated excellent antibiofilm activity, unlike CH paste that showed limited disinfection, even when associated with different antimicrobial agents. Triple antibiotic paste was the most effective medication against biofilm.

Evaluation of postoperative pain and healing following regenerative endodontics using platelet-rich plasma versus conventional endodontic treatment in necrotic mature mandibular molars with chronic periapical periodontitis. A randomized clinical trial

AIM

To evaluate the post-operative pain and the healing of necrotic mature permanent mandibular molar teeth with peri-apical periodontitis after conventional endodontic treatment versus after platelet-rich plasma (PRP) revascularization.

METHODOLOGY

The protocol of this randomized clinical trial was registered at www.

CLINICALTRIALS

gov with identification number NCT03350841. Twenty-eight patients were included in the study after confirming the diagnosis clinically and radiographically. In the first visit, mandibular molar teeth of both groups were mechanically prepared. Double antibiotic paste was prepared and injected then the cavity that was sealed with glass ionomer. At the second visit, the patients were randomized either to control group where standard endodontic treatment was completed by lateral condensation technique or assigned to intervention group where PRP revascularization technique. The degree of spontaneous pain was assessed using numerical rating scale (NRS) pre-operatively, then post-operatively after 6, 12 h and daily for 5 days. Patients were given a placebo to be administrated in case of pain. An analgesic (ibuprofen 400mg) was prescribed in case of persistent pain. Clinical and radiographic healing was assessed after 6 and 12 months. All demographic, baseline and outcome data were collected and statistically analysed.

RESULTS

Regarding the post revascularization/obturation pain, there was no statistically significant difference between severity of pain in the two groups at all time intervals except after 12 h, revascularization group showed statistically significantly higher prevalence of no pain than endodontic treatment group. Regarding the healing; the periapical lesions decrease in size significantly from the pre-operative lesion size in both groups without significant difference between the both groups.

CONCLUSION

Within the limitation of this study, PRP revascularization could be an alternative treatment to root canal treatment but further randomized clinical trials with standardized techniques and long follow up periods are recommended for more reliable results.

The study of the cytotoxic effect of disinfectants

The toxicity of individual disinfectants has been studied in vitro using human cell cultures (HT-29 (epithelial-like cells of colon adenocarcinoma), HEK 293 (human embryonic kidney cells)) to create a model for assessing the toxicity of residual amounts of disinfectants that can enter milk for a person. Standard tests have been used to assess cell viability and amount: methyl tetrazolium (MTT) test, neutral red cell staining (NRP), and sulforhodamine B (SRB) test. Disinfectants have a dose- and time-dependent cytotoxic effect on human cell cultures. IC50avg (concentration of the drug that suppresses a certain cell function by 50%) of disinfectants based on the effect on cell cultures (average value) is Biodez – 117.29 ±14 μl/l, Blanidas – 389.25 ±20.83 μl/l, Virkon-S – 343.04 ±28.04 μl/l, Neochlor  – 473.82 ±30.16 μl/l, Phan – 56.71 ±7.05 μl/l, Chlorination – 343.28 ±27.26 μl/l, Chlorinated lime – 117.35 ±9.44 μl/l. Mean toxic doses for cell cultures are lower than the mean lethal dose (based on literature data) for rats and mice by gastric administration. The novelty is that determining the cytotoxicity of disinfectants in vitro using human cell cultures can significantly reduce the number of animals for establishing LD50 during the registration procedure of new agents, making it possible to make preliminary conclusions about the toxicity of substances at the stage of chemical screening, preliminary hygienic regulation, identify target organs of toxic influence.

Expert consensus on regenerative endodontic procedures

Regenerative endodontic procedures (REPs) is a biologic-based treatment modality for immature permanent teeth diagnosed with pulp necrosis. The ultimate objective of REPs is to regenerate the pulp-dentin complex, extend the tooth longevity and restore the normal function. Scientific evidence has demonstrated the efficacy of REPs in promotion of root development through case reports, case series, cohort studies, and randomized controlled studies. However, variations in clinical protocols for REPs exist due to the empirical nature of the original protocols and rapid advancements in the research field of regenerative endodontics. The heterogeneity in protocols may cause confusion among dental practitioners, thus guidelines and considerations of REPs should be explicated. This expert consensus mainly discusses the biological foundation, the available clinical protocols and current status of REPs in treating immature teeth with pulp necrosis, as well as the main complications of this treatment, aiming at refining the clinical management of REPs in accordance with the progress of basic researches and clinical studies, suggesting REPs may become a more consistently evidence-based option in dental treatment.

12-Year Follow-Up of Regenerative Endodontic Treatment of Immature Permanent Upper Incisors with Acute Abscess

This case report discusses the endodontic treatment of a 7-year-old girl who suffered trauma (intrusion) to the immature upper central incisors secondary to a fall from a bicycle. Thirty days after the accident the patient was brought by her mother for clinical and radiographic assessment with a chief complaint of swelling and tenderness to percussion and palpation. Acute apical abscess associated with immature teeth were diagnosed. A decision was made to perform regenerative endodontic treatment. Access cavities were made and the root canals were disinfected by irrigation with 2.5% sodium hypochlorite. Final irrigation was performed with 17% EDTA. Due to pain and presence of secretions, 2% chlorhexidine gel was applied as an intracanal medicament. Seven days later, at the second visit, the root canals were once again disinfected and the canals of the right and left permanent upper central incisors were filled with double antibiotic paste (metronidazole/ciprofloxacin) and calcium hydroxide paste, respectively. Zinc oxide was mixed in both pastes. At the third visit, after 21 more days, the pastes were removed and the periapical areas were stimulated with a #80 K-file to encourage clot formation within the pulp cavities. A mineral trioxide aggregate (MTA) paste cervical plug was placed and the teeth were restored with glass ionomer cement. Radiographs and CBCT scans demonstrated complete root formations. The patient has been followed for 12 years, with evidence of clinical success throughout.

Antimicrobial Therapeutics in Regenerative Endodontics: A Scoping Review

INTRODUCTION

This review aimed to provide a critical appraisal of alternative antimicrobial strategies in lieu of traditional triple antibiotic paste (TAP).

METHODS

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The literature search was performed in 8 databases (PubMed/Medline, Embase, LILACS, Web of Science, Scopus, BVS, SciELO, and the Cochrane Library), selecting clinical, in vitro, in vivo, and in situ studies that evaluated antimicrobial alternatives to TAP in regenerative endodontics. Studies lacking an experimental TAP group were excluded.

RESULTS

A total of 1705 potentially relevant records were initially identified. From the 38 studies retrieved for full-text reading, 16 fulfilled all selection criteria and were included in the qualitative analysis. According to the study design, 11 studies were solely in vitro, 1 study was both in vitro and in vivo (animal model), 2 studies were solely animal experiments, and 2 studies were clinical trials. The alternative antimicrobial agents to TAP consisted of modified TAP formulations (eg, a combination of TAP with chitosan); TAP-eluting nanofibers; propolis; chlorhexidine (CHX) gels/solutions; double antibiotic pastes composed of distinct combinations of antibiotics; Ca(OH)₂-based formulations; and sodium hypochlorite. Overall, most of the alternative agents performed similarly to TAP, although some strategies (eg, Ca(OH)₂- and CHX-based formulations) seemed to present dubious importance in the control of infection.

CONCLUSIONS

TAP still remains an excellent option in terms of the complete elimination of microorganisms. This review points to the use of electrospun fibers as a drug delivery system to offer a controlled release of the antimicrobial agent, as well as the use of natural compounds, deserving future investigation.

Antimicrobial Activity and Physicochemical Properties of Antibiotic Pastes Used In Regenerative Endodontics

Abstract: The purpose of this study was to evaluate the pH, solubility and antimicrobial action of Calcium Hydroxide Paste (CH), Double Antibiotic Paste (metronidazole+ciprofloxacin-DAP), calcium hydroxide added to DAP (CH/DAP) and Triple Antibiotic Paste (metronidazole + ciprofloxacin+minocycline-TAP). pH (n=10) were measured by pHmeter. Root canals of acrylic teeth (n=10) were filled with the above-mentioned intracanal-dressings, immersed in ultrapure water, and solubility was measured by the difference between the initial and final volume (7,15 and 30 days) by using micro-computed tomography. Enterococcus faecalis biofilm was induced on bovine dentin disc surfaces (n=20), and treated with the pastes for 7 days. Percentage bacterial viability was verified by confocal microscope, with LIVE/DEAD dye. CH and CH/DAP presented the highest pH values. Regarding solubility, after 7 days, antibiotic groups presented significant volume loss. CH and CH/DAP showed no statistical difference compared with the Control in antimicrobial action against E. faecalis biofilm. However, TAP and DAP presented a significant percentage reduction in bacterial population. Due to high solubility of the pastes, renewing antibiotic dressings every 7 days, or using the medications for this period in regeneration protocols is recommended. DAP is indicated for killing E. faecalis in biofilm because it has antimicrobial action similar to TAP. Adding Calcium Hydroxide to DAP significantly decreased its antimicrobial action. In spite of its the low solubility and high pH values, the CH paste showed a low level of antimicrobial action against E. faecalis in biofilm.

Postoperative pain of patients with necrotic teeth with apical periodontitis following single visit endodontic treatment versus multiple visit endodontic treatment using triple antibiotic paste: a randomized clinical trial

Background: A randomized clinical trial was conducted to compare the postoperative pain following endodontic treatment of necrotic teeth with apical periodontitis. Treatments were performed in multiple visits with application of triple antibiotic paste interappointment dressing or single visit without interappointment dressing. Methods: In total 44 participants were assigned randomly into two groups. Group A: multiple visit endodontic treatment with triple antibiotic paste interappointment dressing; group B: single visit endodontic treatment without interappointment dressing. Postoperative pain of participants was assessed after 24, 48, 72 hours and one week using numerical rating scale. Results: No statistically significant difference was found in postoperative pain after 24, 48, 72 hours and one week between the two groups. Conclusion: Triple antibiotic paste as an interappointment dressing in multiple visits endodontic treatment was not proved to reduce the postoperative pain compared to a single visit in patients with necrotic teeth with apical periodontitis who did not have an interappointment dressing. Trial registration: clinicaltrials.gov, NCT02947763. Date: 28th October 2016.

Large Periapical or Cystic Lesions in Association with Roots Having Open Apices Managed Nonsurgically Using 1-step Apexification Based on Platelet-rich Fibrin Matrix and Biodentine Apical Barrier: A Case Series

Teeth having open apices in the absence of a natural apical constriction pose several challenges during conventional endodontic treatment, especially when establishing an apical seal. Treatment is further challenging when these teeth are associated with large periapical or cystic lesions having resulted in expansion and/or thinning of adjacent cortical plates. Although surgical intervention is commonly adopted in the management of such cases, a conservative treatment option offering equally good prognosis is always desirable. This case series describes 3 cases: a 39-year-old woman, a 45-year-old woman, and a 15-year-old boy having teeth with concomitant open apices and large periapical/cystic lesions managed conservatively by (1) following a strict intracanal disinfection protocol, (2) intracanal aspiration with digital decompression of associated swelling, and (3) 1-step apexification for closure of the root apex by placing a preliminary barrier of platelet-rich fibrin (PRF) and a secondary barrier of Biodentine (Septodont, Saint-Maur-des-Fossés, France). In all 3 cases, the treatment outcomes, both clinical and radiographic, were highly satisfactory. PRF and Biodentine collectively rendered an apical plug that proved to be a suitable alternative to commonly used mineral trioxide aggregate in 1-step apexification. Biodentine provides good interfacial adhesion and sealing with dentin attributed to its property of hydroxyapatite crystal deposition at the material-dentin interface. Also, because of its bioactivity, it likely promotes the conversion of adjacent PRF into a calcific barrier, thus reinforcing the apical seal. Additionally, host-modulating responses of PRF contribute in expediting the healing process. Reasonable osseous healing in the periapex could be appreciated as early as 3 months in all patients. The rapidity with which healing occurred may have been an incidental finding but definitely draws attention.