pH changes in dental tissues after root canal filling with calcium hydroxide

Deciphering 3D periodontal fibroblast-macrophage crosstalk in bioactive nanoparticle-guided immunomodulation for treating traumatic dental avulsion

Prolonged extra-oral period in dental avulsion is often associated with loss of viability of Periodontal fibroblasts (PDLF) and increased risk of ankylosis. Root surface treatment with bioactive agents to reduce the risk of ankylosis can be a potential strategy. The objective of the study was to investigate the impact of an engineered chitosan nanoparticles (CSNP), photosensitizer Rose Bengal (RB) functionalized CSNP (CSRB) and sustained dexamethasone (CSDEX) releasing CSNP for application in management of delayed replantation of avulsed teeth. The 3D PDLF-macrophage (Mϕ) collagen model was developed and exposed to LPS, MCSF, RANKL with and without CSDEX/CSNP. Immunofluorescence and cytokine analysis was done at 2 and 7 days to assess cellular interactions. Maxillary right incisors in male Wistar rats were extracted, exposed to extraoral dry or LPS for 1 h and treated with or without CSDEX/CSRB for 1 min before replantation. Rats were euthanized after 21 days for micro-CT, TRAP, and immunofluorescence analysis. CSDEX/CSNP treatment in 3D model significantly reduced CD80, NFATc1, STAT6 and increased CD206 and periostin expression (p < 0.05). TNFα, MMP9 was downregulated and IL10, TGFβ1, MMP2 upregulated with CSDEX/CSNP (p < 0.05). CSDEX/CSRB in animal study significantly reduced resorption, ankylosis, TRAP activity and osteocalcin expression and increased periostin (p<0.05). CSDEX demonstrated higher anti-inflammatory activity by downregulating TNFα, while CSNP upregulated TGFβ1, periostin, and downregulated MMP9. The combination of matrix stabilization with CSRB with periostin upregulation and sustained releasing CSDEX showed potential for hampering root resorption and ankylosis in dental avulsion.

Tissue engineering approaches for dental pulp regeneration: The development of novel bioactive materials using pharmacological epigenetic inhibitors

The drive for minimally invasive endodontic treatment strategies has shifted focus from technically complex and destructive root canal treatments towards more conservative vital pulp treatment. However, novel approaches to maintaining dental pulp vitality after disease or trauma will require the development of innovative, biologically-driven regenerative medicine strategies. For example, cell-homing and cell-based therapies have recently been developed in vitro and trialled in preclinical models to study dental pulp regeneration. These approaches utilise natural and synthetic scaffolds that can deliver a range of bioactive pharmacological epigenetic modulators (HDACis, DNMTis, and ncRNAs), which are cost-effective and easily applied to stimulate pulp tissue regrowth. Unfortunately, many biological factors hinder the clinical development of regenerative therapies, including a lack of blood supply and poor infection control in the necrotic root canal system. Additional challenges include a need for clinically relevant models and manufacturing challenges such as scalability, cost concerns, and regulatory issues. This review will describe the current state of bioactive-biomaterial/scaffold-based engineering strategies to stimulate dentine-pulp regeneration, explicitly focusing on epigenetic modulators and therapeutic pharmacological inhibition. It will highlight the components of dental pulp regenerative approaches, describe their current limitations, and offer suggestions for the effective translation of novel epigenetic-laden bioactive materials for innovative therapeutics.

Evaluation of different irrigation activation techniques for the removal of various medicaments from a simulated internal resorption cavity: an in vitro study

OBJECTIVES

This study aimed to assess the efficacy of different activation techniques in removing calcium hydroxide (Ultracal XS), Ledermix, and Bio-C Temp from simulated internal root resorption (IRR) cavities.

MATERIALS AND METHODS

108 single-rooted maxillary incisors were prepared using Reciproc R50 files. Simulated IRR cavities, 2 mm in diameter and located 8 mm from the apex, were created. Ultracal XS, Ledermix, and Bio-C Temp were applied to the samples, grouped by irrigation activation techniques: Standard Needle Irrigation (SNI), EDDY, Passive Ultrasonic Irrigation (PUI), and XP-endo Finisher (XPF). Medicament removal efficacy was evaluated using a standardized scoring system. Statistical analysis was performed using the Kruskal-Wallis test.

RESULTS

XPF and PUI were more effective than SNI in medicament removal across the groups, with no significant difference. EDDY showed no significant difference than other groups. Ledermix was more effectively removed in all activation groups compared to Bio-C Temp. The XPF was superior in removing Ultracal XS compared to Bio-C Temp. However, none of the groups achieved complete medicament removal.

CONCLUSIONS

XPF and PUI techniques enhance medicament removal efficacy. Bio-C Temp was more difficult to remove from the IRR cavities than other medicaments.

CLINICAL RELEVANCE

Bio-C Temp could be removed from the canals less effectively compared to calcium hydroxide and Ledermix. Among the tested irrigation activation methods, XPF and PUI were found to be more effective at removing the tested medicaments.

Treatment options for impacted maxillary canines and occurrence of ankylotic and resorptive processes: a 20-year retrospective study

BACKGROUND

This 20-year retrospective study aimed to evaluate the treatment methods used in patients with impacted maxillary permanent canines and to determine the occurrence of ankylotic and resorptive processes and their association with potential risk factors.

METHODS

The cohort consisted of 351 consecutive Caucasian patients (120 males and 231 females, mean age 18.4 and 19.9 years, respectively) with 420 impacted maxillary permanent canines. CT and CBCT findings were subsequently confirmed during surgery. Statistical analyses were performed by the generalized linear models, Pearson x2 and Fisher exact tests using the statistical programs R and Statistica v. 14.

RESULTS

A total of 273 (65.0%) impacted canines were aligned in the dental arch by orthodontic traction after surgical exposure, this treatment was predominant in patients under 20 years of age. Surgical extraction was performed in 115 (27.2%) impacted canines and was more common in older patients. Ankylotic changes were recorded in 61 (14.5%) impacted canines. The probability of ankylosis increased with age, particularly after the patient's 20th year of life (p < 0.001). Patients were 1.2% likely to develop ankylosis at age 15 years, 4.3% at age 20 years, 14.1% at age 25 years, and 96.8% at age 45 years. Invasive cervical root resorption (ICRR) was found in 8 (1.9%) canines. In 4 canines (1.0%), root ankylosis in addition to ICRR was observed. In contrast to ankylosis, whose frequency of occurrence increased with age, the occurrence of ICRR resulting from PDL damage during surgery was more typical in younger patients. Canines in a high position above the root apices of the adjacent teeth, with a horizontal inclination of the longitudinal axis, with the crown located deep in the center of the alveolar bone and with labiopalatal position, should be considered critically impacted canines with a high risk to failure of orthodontic traction.

CONCLUSION

In conclusion, the treatment of impacted canines depends mainly on the age of the patient, and the position and inclination of the longitudinal axis of the impacted tooth. To select an adequate treatment method, we recommend CBCT examination, which allows a precise analysis of the position of impacted canines.

Long-term complications and management of dental trauma in the adult patient - Part 1: fractured teeth, pulpal complications and resorption

Dental trauma is one of the most common injuries encountered in the younger population. This can have a long-term impact on the patient's overall quality of life as they may have to deal with the sequelae of these injuries for years to come. Young boys experience dental trauma more frequently than young girls and one of the most common outcomes of these injuries are fractured teeth. This first paper in a two-part review series aims to provide an overview of dental trauma followed by a discussion on management of fractured teeth, associated pulpal complications and resorption. These can be uncomplicated fractures involving enamel and/or dentine, or complicated fractures involving enamel, dentine and pulp. They can involve the crown, the crown and root together, or present solely as root fractures. Pulpal complications can lead to pulp necrosis or pulp canal obliteration. Resorption can be internal or external, inflammatory, or replacement type. The management of each of these injuries begins with a thorough assessment followed by initiating emergency treatment to stabilise the presenting condition. This is followed by a long-term treatment plan which aims to address the patients' aesthetic and functional requirements and provide the patient with the most suitable treatment outcome in the hope to improve their sense of wellbeing and overall quality of life.

Root canal therapy used in conjunction with follow-ups for the nonsurgical handling of an enormous periapical lesion of endodontic origin: Clinical case record

Key Clinical Message

The main objective of root canal therapy is to locate all the canals, cleaning, and shaping, and obturation to obtain fluid tight seal and to heal the periapical lesion if present.

Abstract

The proper cleaning, shaping, and disinfection of the pulp chambers, as well as the filling of the canals, are critical to the efficacy of treatment with root canals. The success of an endodontically treated tooth is dependent on the accuracy of the diagnosis, disinfection, cleaning and shaping, obturation, and finally, the prosthetic rehabilitation management. Root canal therapy should provide a hermatic as well as fluid impenetrable seal which prevents the progression of periapical infection. There are two ways to treat such lesions: surgical and nonsurgical methods. If the root canal is cleaned, shaped, and sealed properly and adequately without the use of a surgical procedure, these lesions will recover during nonsurgical root canal therapy. This case series focuses primarily on the nonsurgical treatment of an enormous periapical lesion and provides evidence that these lesions respond well without surgery.

Evaluation of rise in pH and oxygen release at the site of simulated external root resorption cavities using different oxygen-releasing biomaterials: An in vitro study

Context

External inflammatory root resorption has rapid onset and progresses aggressively. It leads to cementum loss, which allows communication between the infected pulp and the periodontium through the denuded dentinal tubules. Primary management strategy includes adequate chemomechanical debridement and lesion arrest for which maintaining alkaline pH and aerobic conditions is essential for healing and repair of the resorption defect.

Aims

The aim of this study is to evaluate rise in pH and oxygen release at the site of simulated external root resorption cavities using different oxygen-releasing biomaterials.

Materials and Methods

In 40 extracted single-rooted teeth access opening and chemomechanical debridement were done. Cavities simulating resorption defect are prepared on the roots. The samples are divided into four groups (n = 10) based on the biomaterial used. After placing the biomaterial, the root apices were sealed. Half of the samples from each group were tested for oxygen release using dissolved oxygen meter and the other half for rise in pH using pH meter at 7, 14, 21, and 28 days.

Statistical Analysis

The pH values were analyzed using Friedman 2-way analysis of variance (ANOVA) and Kruskal-Wallis test. Oxygen release was measured using the two-way and repeated-measures ANOVA.

Results

Calcium peroxide group showed the highest mean pH and oxygen release than other groups at any given point of time.

Conclusions

Incorporating oxygen-releasing biomaterials such as calcium peroxide and perfluorodecalin into intracanal medicaments, such as calcium hydroxide, creates an alkaline and oxygen-enriched milieu in the periapical tissues.

Comparative evaluation of antimicrobial efficacy of different combinations of calcium hydroxide against Enterococcus faecalis

BACKGROUND

The study aims to compare the synergistic antibacterial efficacy of different combinations of calcium hydroxide as an intracanal medicament against E. faecalis.

MATERIAL AND METHODS

The current study included four hundred extracted human permanent mandibular premolar teeth. After complete chemo-mechanical preparation, the middle third of the root was sectioned using a rotary diamond disc and a total of 400 samples were obtained. The specimens were inoculated with E. faecalis for 21 days. After that, specimens were divided into five groups (n = 80) based on materials used for the disinfection of samples: Group I, calcium hydroxide alone; Group II, calcium hydroxide + 2% chlorhexidine gel; Group III, calcium hydroxide + 2% chitosan gel; Group IV, calcium hydroxide + 0.02% silver nanoparticle gel; Group V, calcium hydroxide + Bioactive glass S53P4. Dentin shavings from the apical third were obtained from the inner third of dentin were obtained using gates glidden no.1 to the apical depth, followed by no.2, 3, 4 and 5 analyzed for E. faecalis using the culture method. One-way analysis of variance (ANOVA) was used for data analysis, followed by post-hoc Tukey's test for multiple comparisons of means to check the difference in bacterial inhibition between the groups.

RESULTS

ANOVA results revealed a significant reduction of bacterial counts in all the groups compared (p < 0.001). Intergroup comparison showed maximum bacterial reduction (p < 0.001) with calcium hydroxide + bioactive glass S53P4 compared with other groups.

CONCLUSION

Synergistic effect of calcium hydroxide showed better bacterial reduction compared to calcium hydroxide alone. Among the combinations evaluated, calcium hydroxide with bioactive glass, found to be most effective compared to other groups.

Influence of intracanal medicaments on the periodontal and periapical healing in concurrent endodontic-periodontal lesions with/without communication: a systematic review and meta-analysis

OBJECTIVES

The purpose of this review is to determine the effectiveness of intracanal medicament (ICM) on periodontal and periapical healing (PH) of concurrent endodontic-periodontal lesions with/without communication in permanent teeth.

MATERIALS AND METHODS

The pre-defined protocol was registered in PROSPERO, and a literature search using keywords was conducted on PubMed, Scopus, Cochrane, Embase electronic databases, and Gray literature and was hand-searched until August 2023. Two reviewers independently screened the title and abstracts using the inclusion criteria. Randomized or non-randomized clinical trials, cohort studies, and case-control studies were included in the review. The same reviewers extracted the study-level data and assessed the risk of bias using the Cochrane Risk of Bias 2.0 and the Newcastle-Ottawa Scale (NOS) independently. Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to assess the certainty of evidence. Random effects meta-analysis was performed on eligible studies using Revman software.

RESULTS

A total of 598 records were identified from the database search; seven studies met the inclusion criteria and were included in the review. Four randomized clinical trials, two prospective cohorts, and one retrospective case-control study with 362 patients were included. Calcium hydroxide (CH) was the most commonly used ICM, followed by using chlorhexidine gel in four studies. Periodontal therapy was performed as initial scaling and root planning (SRP) in all studies, along with open flap debridement (OFD) in three randomized clinical trials. The time lapse between two treatment protocols was variable (ranging from 1 week to 3 months). All studies exhibited a decrease in probing depth (PD) and an increase in clinical attachment level (CAL) after the treatment. Meta-analysis showed insignificant differences between different ICM materials, and the certainty of evidence was low.

CONCLUSION

In patients with/without concurrent endodontic-periodontal lesions, intracanal medication improved clinical periodontal parameters following endodontic therapy. In terms of influence on periapical healing, the results were inconclusive.

CLINICAL RELEVANCE

Two-visit RCT may be considered since it allows for the placement of an ICM in endodontic-periodontal lesions with/without communication. Sufficient time should be allowed after endodontic therapy for any potential periodontal regeneration to occur.

A comparison of hydroxyl ion diffusion through root dentine from various calcium hydroxide preparations

Different calcium hydroxide [Ca(OH)2 ] formulations are available. The aim was to assess differences in hydroxyl ion release with different formulations. Sixty-six teeth were divided one control (n = 6) and four experimental (n = 15) groups: (i) Pulpdent Paste; (ii): DT Temporary Dressing; (iii): Ca(OH)2 powder/saline; (iv): Ca(OH)2 points; (v): no medicament. pH was measured in inner dentine and outer dentine cavities over 12 weeks. Inner dentine pH rose rapidly for all groups except the points and controls. Peak pH was reached by day 2 before dropping and stabilising (8.0-9.2). Outer dentine pH rose steadily until day 21 for aqueous solutions and then stabilised (8.0-8.5). The points had minimal pH increase for the entire period. There were no significant differences in hydroxyl ion release between the aqueous solutions. Type of paste base did not affect release and diffusion of hydroxyl ions which continued for 84 days.

Effect of different activation methods on the intratubular penetration of CaOH2 paste: Ex-vivo analysis by confocal laser scanning microscopy

The aim of this study was to evaluate the maximum penetration depth (MPD) and penetration area (PA) of CaOH2 paste agitated by different methods and to measure the pH after performing these methods. Fifty-five mandibular premolars were divided into control, GL and 4 experimental groups, GEC, GXP, GEDDY and GI (n = 11), where the paste was agitated with Easy Clean, XP-endo Finisher, EDDY and Irrisonic, respectively. The canals were instrumented and irrigated with NaOCl. The paste was manipulated with propylene glycol and rhodamine B dye. Root sections were examined using confocal laser scanning microscopy. There was no difference between groups regarding PA (p > 0.05). At 5 mm, MPD was greater in GEC than in GL or GEDDY, and greater in GI than in GL (p < 0.05). At 2 mm, MPD was greater in GEC than in the other groups (p < 0.05). In conclusion, both Easy Clean and Irrisonic promoted deeper paste penetration and were associated with higher pH levels.

Non-cytotoxic Root Canal Dressing with Improved Antimicrobial Efficacy

INTRODUCTION

Recurrent endodontic infections are primarily caused by Enterococcus faecalis and are more challenging to treat, compared with primary infection of the root canal system. Calcium hydroxide (CH) is used as an interappointment dressing in endodontics despite its inefficacy against E. faecalis and other pathogens. To improve antimicrobial properties and limit cytotoxicity of CH, we added salicylic acid to CH (CASA) to disinfect the canal. CASA overcomes the main pathogen responsible for recurrent endodontic infections. The aim of this study was to evaluate the antimicrobial activity of CASA and its cytotoxicity against dental pulp stem cells (DPSCs) and its effect on the differentiation potential of DPSCs.

METHODS

Mature E. faecalis biofilm cultured on dentin chips was exposed to CASA and studied using confocal laser scanning microscopy. The dose-dependency of CASA was also studied using the liquid suspension test. The cytotoxicity was tested against DPSCs, and its effect on the expression of osteocalcin and alkaline phosphatase was studied.

RESULTS

CASA produced larger zones of inhibition than CH for all species tested and demonstrated superior efficacy than CH against E. faecalis biofilm. Cytotoxicity studies indicated DPSC's high tolerance for CASA; addition of CASA to DPSCs was observed to increase the expression of biological markers related to mineralization.

CONCLUSIONS

CASA was proved to have superior antibacterial efficacy against E. faecalis when compared with CH. It also increased the expression of some DPSC differentiation markers involved in mineralization.

A comparative evaluation of calcium ion release and pH change using calcium hydroxide nanoparticles as intracanal medicament with different vehicles - An in vitro study

Context

Nano-calcium hydroxide (NCH) has been proven to have several advantages over normal calcium hydroxide, supporting in its possible use as an intracanal medicament.

Aim

The aim is to evaluate and compare calcium ion release and pH change using NCH with different vehicles as intracanal medicament.

Subjects and Methods

Sixty freshly extracted premolars were decoronated at the cementoenamel junction level and the length was standardized. Canals were enlarged to F3 size using protaper rotary system. The samples were divided into three groups (n = 20), namely NCH + distilled water (Group 1), NCH + propylene glycol (Group 2), and NCH + chitosan (CT) (Group 3). Each sample was suspended in 6 ml of distilled water using silicone putty with only the apical third of the roots immersed. The pH and calcium ions were assessed at 24 h, 7 days, 15 days, and 30 days using a pH meter and ultraviolet spectrophotometer, respectively.

Statistical Analysis

Comparison of mean calcium release and pH change was made using Kruskal-Wallis ANOVA with post-hoc Dunn's test. The level of significance was set at 5%.

Results

A significant difference was seen in the calcium ion release and pH change among the three groups at 24 h, 7 days, 15 days, and 30 days.

Conclusions

NCH mixed with propylene glycol showed alkaline pH and adequate release of calcium ions till 30 days. NCH mixed with CT exhibited a high pH at the end of 30 days. Both combinations proved their efficacy as intracanal medicaments.

Surface Microstructure of Two Bioceramics: Calcium-Enriched Mixture and Cold Ceramic in Setting Environments with Different pH Values

Introduction

The pH of the setting environment could alter the surface characteristics of bioceramics. The present study aimed to assess the surface microstructure of calcium-enriched mixture (CEM cement) and cold ceramic (CC) in setting environments with different pH values.

Materials and Methods

12 dentin blocks with 3 mm height and internal diameter were prepared. CEM cement and CC were prepared and packed into the blocks. Samples in each bioceramics group (n = 6) were divided into 3 subgroups (n = 2) and exposed to acid, pH of 7.4, and alkaline pH for 1 week. Specimens were prepared for evaluation under a scanning electron microscope using backscattered electron (BSE) detectors. Monitoring of pH changes was rendered with a pH meter through the setting process.

Results

BSE detection in an acidic environment showed more amorphous microstructures in CC specimens in comparison to CEM cement. In pH of 7.4 and alkaline pH, more unhydrated structures were observed in CEM cement compared with CC samples. During the first 48 h of the setting process, the pH changes of setting environments were more rapid in the CEM cement group in comparison to CC samples.

Conclusion

pH changes during the setting process of cement could affect the surface microstructure and physical properties. In acidic environments, the crystallization of CC cement is more disrupted than that of CEM cement.

Efficacy of hypochlorous acid (HOCl) fog in sanitizing surfaces against Enterococcus faecalis

BACKGROUND

Fogging is an efficient method when disinfection of large areas is desired.

METHODS

Two methods of ultrasonic fogging, pulsed and continuous, were compared on bacteria dried on either aluminum or polystyrene surfaces. We characterized commercial and home-made hypochlorous acid (HOCl) with respect to storage and means of production.

RESULTS

We found that the initial chlorine concentration of the commercial solution was approximately 550 ppm, and when stored open under ambient conditions, the chlorine content decreased at a rate of 30% every 100 days. The HOCl produced using the home synthesizers had a maximum chlorine content of 257.6 ppm which decayed by 65% after 100 days. A second synthesizer produced a liquid with high chlorine content and pH, 750ppm and pH = 8.55. The anti-bacterial efficacy was probed using Enterococcus faecalis, a persistent source of infection in public and clinical spaces. Time course studies determined that E. faecalis could survive dry on surfaces for more than 12 weeks, but was easily eliminated in half the fogging time.

CONCLUSIONS

The most effective mode of application was determined to be continuous fogging where a 6.59 log reduction was established in vertical geometry. The optimal pulsed fogging protocol produced a similar reduction, but required nearly 5 times as long. The home synthesized versions yielded much lower log bacterial reductions. No significant differences in outcome were determined between polymer or metal surfaces.

Physicochemical and Antibacterial Properties of Conventional and Two Premixed Root Canal Filling Materials in Primary Teeth

In this study, some physicochemical and antibacterial properties of three root canal filling materials for primary teeth, Calplus “CP” (Prevest DenPro, Lewes, DE, USA), Bio-C Pulpecto “Bio-CP” (Angelus, Basil, Londrina, Paraná, Brazil), and Zinc Oxide and Eugenol “ZOE” (Prevest DenPro, Lewes, DE, USA) were compared. For each material, the pH, solubility, contact angle, and crystalline microstructure under SEM were evaluated. Their antibacterial activity against Enterococcus faecalis was determined through direct tests. The Kruskal−Wallis test was used to analyze the results using a one-way analysis of variance on ranks. All the materials had an alkaline pH at 3, 24, and 72 h, with CalPlus having the highest (p < 0.05). Bio-CP was more soluble during the evaluation period (24 h) than ZOE and CalPlus (p < 0.05). Bio-CP and ZOE demonstrated the creation of crystallite structures on their surfaces after immersion in PBS at 37 °C, whereas CalPlus showed none. The lowest contact angle was observed for Bio-CP (53 ± 1.5°); contact angles of (86 ± 4°) and (96 ± 1°), respectively, were observed after 10 s of the deposition of the water drop for CalPlus and ZOE. In conclusion, according to this study, there is still a need to develop new filling materials for primary teeth. ZOE, CalPlus and Bio-CP demonstrated different physicochemical and antibacterial properties, but none of the materials had optimal properties and could be considered the most suitable filling material for primary teeth pulpectomy. Bioceramics in their current state are not an alternative. The physicochemical and antibacterial properties still need improvement to fit the intricate anatomy of primary teeth.

Tooth root resorption: A review

Tooth root resorption is multifactorial, leading to progressive destruction and eventual loss of tooth root dentin and cement. There are internal and external types of root resorption, each having its variety. The etiology and pathogenesis of tooth root resorption are poorly understood, and the most significant etiological factors are trauma, pulpal infection, tooth bleaching, and orthodontic treatment. Tooth root resorption is primarily asymptomatic; thus, it is revealed accidentally by radiographic examination. Progressive clinical manifestations are pain, tooth discoloration, tooth mobility, and other conditions. Awareness of the causes and risk factors allowing tooth root resorption, and regular radiographic examination, in case of necessity, make it possible to reveal resorption at an early stage and to prevent its further development. Thus, the aim of this study is to present etiopathogenesis, a clinical course, and diagnostic peculiarities of internal and external types of tooth root resorption, enabling practicing dentists to timely diagnose root resorption and take appropriate measures to avoid further complications. Within the limitation of this review, even though the etiopathogenesis of tooth root resorption is yet not fully understood, it is suggested that the etiological factors fall into two groups (endogenic and exogenic) to enhance further understanding of the possible causes and mechanisms of root resorption and allow practitioners to monitor high-risk patients and make timely diagnoses. Moreover, radiographic examination and CBCT are indispensable for the diagnosis of root resorption.

Evaluation of pH and calcium ion release at the simulated external root resorption cavities of teeth obturated with bioceramic sealer

Objective

The purpose of this study was to evaluate pH and calcium ion release at the outer dentin surface of simulated external root resorption cavities after root canals obturated with bioceramic root canal sealer compared with those medicated with calcium hydroxide.

Materials and Methods

Sixty extracted human single‐rooted teeth were selected and instrumented. External root resorption cavities were prepared at the lingual surface of the root. The teeth were randomly divided into three groups: (1) Bioceramic sealer group, canals were obturated with gutta‐percha and BioRoot sealer; (2) Calcium hydroxide group, canals were medicated with UltraCal XS; (3) Control group, canals were left empty. Thirty specimens were used for evaluation of pH at 7, 14, and 28 days (n = 10 per group) and the other 30 specimens were used for evaluation of calcium ion diffusion at 28 days (n = 10 per group).

Results

Calcium hydroxide group showed the highest median pH value at all time points (7, 14, and 28 days). Both calcium hydroxide and bioceramic sealer groups showed significantly higher median pH values compared with control (p < .001). Comparing within groups, both bioceramic sealer group and calcium hydroxide group showed significantly decreased median pH over time, while the median pH of the control did not show any significant difference among Days 7, 14, and 28. Both calcium hydroxide and bioceramic sealer groups had significantly higher calcium ion release than control. Notably, bioceramic sealer group showed significantly higher calcium ion release than the calcium hydroxide group (p < .01).

Conclusions

Root canals obturated with gutta‐percha and bioceramic sealer showed high calcium ion levels at the simulated external root resorption cavities but did not show an extended period of alkaline pH.

Present status and future directions of intracanal medicaments

Two fundamental goals of endodontic treatment are to prevent or treat apical periodontitis. From a predictive perspective, several variables can affect the outcome of root canal treatment. Some of these variables depend on intraoperative factors, which include irrigation technique, size of the apical preparation, use of intracanal medicaments or the number of appointments necessary to complete the treatment. However, the outcome may also be affected by host and microbial factors. The intensity of periradicular bone loss or tissue damage, the presence of preoperative pain and associated conditions such as mechanical allodynia and central sensitization, the anatomical complexity of the apical portion of the canal, and the virulence and longevity of the bacterial infection can all have a profound influence on the outcome. Furthermore, numerous medical conditions have been reported to decrease the capability of the immune system to heal the periapical tissues. It is the clinician's responsibility to analyse these variables and incorporate them into the disinfection strategy to maximize the chances of healing. This narrative review will focus on the present status of intracanal medicaments, the clinical indications for their use and future directions for research.

Functional screening of a human saliva metagenomic DNA reveal novel resistance genes against sodium hypochlorite and chlorhexidine

Objective

Many sections of the health care system are facing a major challenge making infectious disease problematic to treat; antimicrobial resistance (AMR). Identification and surveillance of the resistome have been highlighted as one of the strategies to overcome the problem. This study aimed to screen for AMR genes in an oral microbiota, a complex microbial system continuously exposed to antimicrobial agents commonly used in dental practice.

Materials and methods

As a significant part of the oral microbiome cannot be conventionally cultured, a functional metagenomic approach was chosen. The human oral metagenomic DNA was extracted from saliva samples collected from 50 healthy volunteers in Norway. The oral metagenomic library was then constructed by ligating partially digested oral metagenome into pSMART BAC vector and introducing into Escherichia coli. The library was screened against antimicrobials in dental practices. All resistant clones were selected and analyzed.

Results

Screening of the oral metagenomic library against different antimicrobials detected multiple clones with resistance against chlorhexidine, triclosan, erythromycin, tetracycline, and sodium hypochlorite. Bioinformatic analysis revealed both already known resistance genes, including msr, mef(A), tetAB(46), and fabK, and genes that were not previously described to confer resistance, including recA and accB conferring resistance to sodium hypochlorite and chlorhexidine, respectively.

Conclusion

Multiple clones conferring resistance to antimicrobials commonly used in dental practices were detected, containing known and novel resistant genes by functional-based metagenomics. There is a need for more studies to increase our knowledge in the field.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-02000-5.

Present status and future directions: Endodontic management of traumatic injuries to permanent teeth

The prognosis of traumatized teeth depends largely on the fate of the pulp and its treatment. This review aims to update the present status on the endodontic management of traumatic injuries to permanent teeth and to identify relevant research areas that could contribute to an improvement in diagnosis and treatment of traumatized permanent teeth. Future research should pay greater attention to (1) diagnostic methods to assess the perfusion of the pulp and enhance detection of tooth cracks and initial signs of root resorption; (2) improved materials for vital pulp treatment; (3) studies focusing on type and duration of splinting after root fractures; (4) antiresorptive intracanal medication in case of posttraumatic pulp necrosis and infection-related resorption and (5) long-term data on the apical barrier technique compared to revitalization.

Antimicrobial Effect of Calcium Hydroxide Combined with Electrolyzed Superoxidized Solution at Neutral pH on Enterococcus faecalis Growth

Objective

To evaluate the effect of the combination of calcium hydroxide (Ca(OH)₂) and a novel electrolyzed superoxidized solution at neutral pH, known as OxOral® on Enterococcus faecalis growth in root canals.

Methods

Sixty human teeth were used, from which root canals were infected and randomly divided into the following treatment groups: saline solution, saline solution plus Ca(OH)₂, OxOral®, and OxOral® plus Ca(OH)₂.

Results

A permanent reduction in bacterial growth was observed at days 1, 6, 12, and 18 after OxOral® plus Ca(OH)₂ treatment from 4.4 ± 0.074 log₁₀ CFU/mL to 0.0 ± 0.001 log₁₀ CFU/mL. In addition, alkaline conditions maintenance was observed from application time (pH = 12.2 ± 0.033) to 18 d posttreatment (pH = 12.6 ± 0.083).

Conclusion

The combination of OxOral® and Ca(OH)₂ provides an alkaline pH and inhibits E. faecalis growth into the root canals. Our study opens the possibility for further research on the use of OxOral® in endodontic therapy.

Influence of Apical Patency, Coronal Preflaring and Calcium Hydroxide on the Accuracy of Root ZX Apex Locator for Working Length Determination: An In Vitro Study

Aim:

One of the main steps in a successful endodontic treatment is determining the correct working length (WL) of the root canal. In this regard, electronic apex locators (EAL) have been widely used for measuring the WL. The accuracy of EALs in determining the WL may be influenced by various factors. This study is aimed to evaluate the effects of apical patency, coronal preflaring, and calcium hydroxide on the accuracy of the EAL.

Materials and Methods:

In this in vitro study, 20 central incisor single-rooted human teeth with fully formed apex were considered. Then, samples were randomly divided into two study groups, ten samples in each group. The WL was determined and recorded at 0.5 mm distance to the apex using Root ZX apex locator before and after creating patency, coronal preflaring, and calcium hydroxide administration. All WLs were measured separately for each tooth and reviewed independently by two experienced operators with extensive experience in using EALs. Paired t test and Wilcoxon signed-rank test were applied and the significant level was at .05.

Results:

Statistical analysis of the obtained data showed a significant decline in the WL after apical patency and coronal preflaring ( P < .05). Moreover, WL exhibited a significant enhancement after calcium hydroxide application ( P < .05).

Conclusion:

Apical patency and coronal preflaring increased the accuracy of apex locators in determining the WL of the teeth. Besides, calcium hydroxide residues in the root canal reduced the accuracy of the apex locator.

Endodontic management of traumatized permanent teeth: a comprehensive review

The pulp plays a key role in the treatment of traumatic dental injuries (TDIs) and is strongly associated with the outcome, particularly in severe cases. A correct pulp diagnosis is essential as it forms the basis for developing the appropriate management strategy. However, many TDIs are complex, and their treatment requires a profound knowledge of the physiological and pathological responses of the affected tissues. This comprehensive review will look at the dentine-pulp complex and its interaction with the surrounding tissues following TDIs. The literature up to 2020 was reviewed based on several searches on PubMed and the Cochrane Library using relevant terms. In addition to the recently revised guidelines of the International Association of Dental Traumatology, this article aims to provide background information with a focus on endodontic aspects and to gather evidence on which a clinician can make decisions on the choice of the appropriate endodontic approach for traumatized permanent teeth.

Evaluation of the diffusion of calcium hydroxide-based medicaments through the dentinal tubules and apical foramen: A mass spectrometry study

Aims:

This mass spectrometry study investigated the diffusion of hydroxyl and calcium ions from a calcium hydroxide intracanal medicament (Pulpdent^®) when used alone or mixed in equal parts with a steroid–antibiotic paste (Ledermix^®).

Materials and Methods:

The pH (using pH meter) and calcium ion concentration (using inductively coupled plasma-mass spectrometry) of the diffused medicaments were assessed using endodontically prepared human extracted teeth with either a sealed or a patent apex, at time intervals of 1, 3, 8, 24, and 168 h.

Statistical Analysis:

A one-way ANOVA was used to explore differences between and within groups, with Tukey–Kramer/Games–Howell posttests.

Results:

In both situations tested, Pulpdent^® showed greater release of both calcium and hydroxyl ions than when mixed in equal parts with Ledermix^®. Greater initial release of both ions occurred in roots with a patent apex, but by 1 week there was no significant difference between the two. If a 50:50 combination of Pulpdent^® paste and Ledermix^® paste is used, there is a lower release of calcium ions and hydroxyl ions than using Pulpdent^® paste alone.

Conclusion:

With both Pulpdent^® paste alone and Pulpdent^® paste mixed equally with Ledermix^® paste, the major pathway for movement of hydroxyl ions and calcium ions is diffusion through the dentine of the root, with the apex playing only a minor role.

Effect of calcium hydroxide mixed with lidocaine hydrochloride on postoperative pain in teeth with irreversible pulpitis and symptomatic apical periodontitis: a preliminary randomized controlled prospective clinical trial

OBJECTIVES

To investigate the effect of calcium hydroxide mixed with lidocaine HCl on postoperative spontaneous pain.

MATERIALS AND METHODS

Sixty patients having irreversible pulpitis and symptomatic apical periodontitis with a preoperative spontaneous pain and percussion pain which was more than 50 on a visual analogue scale (100 mm VAS) were included in this study. After the preparation of the root canals, the patients were randomly distributed into two groups according to the calcium hydroxide vehicle, control group (mixed with saline) and calcium hydroxide mixed with lidocaine HCl (n = 30). Postoperative spontaneous pain scores were recorded by a VAS every day for a week. Data were analysed using one-way analysis of variance, chi-squared test and Mann-Whitney U tests (p = 0.05).

RESULTS

The calcium hydroxide mixed with lidocaine HCl group resulted in significantly less pain compared with the calcium hydroxide mixed with saline group during days 1 to 4 (p < 0.05). There were no significant differences between the groups in terms of postoperative percussion pain levels (p > 0.05).

CONCLUSION

Within the limitations of this study, it can be concluded that the calcium hydroxide mixed with lidocaine HCl can be beneficial in reducing postoperative pain in teeth with irreversible pulpitis and symptomatic apical periodontitis.

CLINICAL RELEVANCE

The calcium hydroxide mixed with lidocaine HCl can be beneficial in reducing postoperative pain in teeth with irreversible pulpitis and symptomatic apical periodontitis.

CLINICAL REGISTRATION NUMBER

TCTR20181121003.

Raman spectroscopic study of the effect of the use of laser/LED phototherapy on the repair of complete tibial fracture treated with internal rigid fixation

This study aimed to assess the repair of complete surgical tibial fractures fixed with internal rigid fixation (IRF) associated or not to the use of mineral trioxide aggregate (MTA) cement and treated or not with laser (λ = 780 nm, infrared) or LED (λ = 850 ± 10 nm, infrared) lights, 142.8 J/cm² per treatment, by means of Raman spectroscopy. Open surgical tibial fractures were created on 18 rabbits (6 groups of 3 animals per group, ∼8 months old) and fractures were fixed with IRF. Three groups were grafted with MTA. The groups of IRF and IRF + MTA that received laser or LED were irradiated every other day during 15 days. Animals were sacrificed after 30 days, being the tibia surgically removed. Raman spectra were collected via the probe at the defect site in five points, resulting in 15 spectra per group (90 spectra in the dataset). Spectra were collected at the same day to avoid changes in laser power and experimental setup. The ANOVA general linear model showed that the laser irradiation of tibial bone fractures fixed with IRF and grafted with MTA had significant influence in the content of phosphate (peak ∼960 cm^-1) and carbonated (peak ∼1,070 cm^-1) hydroxyapatites as well as collagen (peak 1,452 cm^-1). Also, peaks of calcium carbonate (1,088 cm^-1) were found in the groups grafted with MTA. Based on the Raman spectroscopic data collected in this study, MTA has been shown to improve the repair of complete tibial fractures treated with IRF, with an evident increase of collagen matrix synthesis, and development of a scaffold of hydroxyapatite-like calcium carbonate with subsequent deposition of phosphate hydroxyapatite.

Physical properties of MTA, BioAggregate and Biodentine in simulated conditions: A micro-CT analysis

The aim of this study was to evaluate the physical properties of calcium-silicate based cements as retrograde filling in different pH and blood conditions using micro-CT. Eighty-four teeth were obturated and after root-end resection, 3 mm-deep root-end cavity was ultrasonically prepared. The samples were divided into four test groups (n=21). Cements were freshly prepared and analyzed with micro-CT before and after exposed. The test groups were exposed for four days to environments containing acid, alkali, or blood. An acidic pH significantly reduced the volume of all materials after four days and differed from the other environments. Biodentine has the highest percentage of loss in volume and density after treatment in an acidic environment. Porosity formation in the acidic medium was observed in Biodentine amongst all materials. The three-dimensional structures of all materials changed after exposed to an acidic pH, while fewer changes were observed in the structures of materials treated with blood and alkali.

Crown Amputation and Vital Pulpotomy to Resolve an Unusual Orthodontic Problem in a Kinkajou

This report describes the evaluation and treatment of a malocclusion problem in a kinkajou. The treatment included crown reduction and direct pulpotomy of the mandibular canine teeth. The report includes an extensive explanation of vital pulpotomy for all teeth and supports crown reduction as a viable option for treatment of malocclusion.

Intracanal Calcium Hydroxide Therapy - The Webber Technique

Calcium hydroxide powder has been used as a treatment medication for different pathologies of the teeth. This article describes the physiological effects and general principles involved in using calcium hydroxide. The indications for its use and the contraindications are described. Filling and refilling the root canal with calcium hydroxide using the Webber technique induces a calcified tissue barrier and stimulates osteogenic healing. A case report using the Webber technique is included.

Microbiological aspects of traumatic injuries

After traumatic injuries to teeth, microorganisms may invade the compromised pulp tissue and initiate pulp infection and periapical inflammation. In addition to bone resorption that typically accompanies pulp necrosis, root resorption frequently occurs. Root resorption has several variants that may occur shortly after the trauma or at a later stage. The pathological changes seen after traumatic injuries to teeth are invariably linked to the presence of microbial irritants. The presence of bacterial biofilms in the dental pulp space can be treated with regenerative or therapeutic endodontic procedures. However, necrosis of periodontal ligament is usually terminal for the tooth involved. In this review, the sources of bacteria after traumatic injuries are discussed. The types and role of microorganisms involved in the pathogenesis of endodontic pathosis after traumatic injuries are presented, and contemporary approaches for the management of these conditions are reviewed. Contemporary antimicrobial strategies are discussed. The rationale for the use of systemic and topical antimicrobials is presented. Finally, novel approaches to the use of antimicrobial therapies, particularly in regenerative procedures, are reviewed.

Calcium phosphate nanoparticles as intrinsic inorganic antimicrobials: In search of the key particle property

One of the main goals of materials science in the 21st century is the development of materials with rationally designed properties as substitutes for traditional pharmacotherapies. At the same time, there is a lack of understanding of the exact material properties that induce therapeutic effects in biological systems, which limits their rational optimization for the related medical applications. This study sets the foundation for a general approach for elucidating nanoparticle properties as determinants of antibacterial activity, with a particular focus on calcium phosphate nanoparticles. To that end, nine physicochemical effects were studied and a number of them were refuted, thus putting an end to frequently erred hypotheses in the literature. Rather than having one key particle property responsible for eliciting the antibacterial effect, a complex synergy of factors is shown to be at work, including (a) nanoscopic size; (b) elevated intracellular free calcium levels due to nanoparticle solubility; (c) diffusivity and favorable electrostatic properties of the nanoparticle surface, primarily low net charge and high charge density; and (d) the dynamics of perpetual exchange of ultrafine clusters across the particle/solution interface. On the positive side, this multifaceted mechanism is less prone to induce bacterial resistance to the therapy and can be a gateway to the sphere of personalized medicine. On a more problematic side, it implies a less intense effect compared to single-target molecular therapies and a difficulty of elucidating the exact mechanisms of action, while also making the rational design of theirs for this type of medical application a challenge.

Diffusion of hydroxyl ion on external root surface using different irrigating solutions: An In vitro study

AIMS

The aim of this study was to evaluate the diffusion of hydroxyl ion to the external root surface using different irrigating solutions and intracanal medication with calcium hydroxide.

MATERIALS AND METHODS

Sixty bovine tooth roots were randomly divided into six experimental groups (n = 10), according to the irrigating substance used during biomechanical preparation: 12% glycolic propolis extract (PROP); 20% glycolic ginger extract (GENG); 2% sodium hypochlorite with surfactant (NaOClS); 2% chlorhexidine gel (CLX); 2.5% sodium hypochlorite (NaOCl); and physiological saline solution. After filling the root canals with calcium hydroxide paste, pH measurements were taken directly at the external cavities over time intervals of up to 30 days.

STATISTICAL ANALYSIS USED

Data were submitted to two-way ANOVA and Tukey's test (P < 0.05).

RESULTS

The pH of the external root surface was increased when the surfactant associated with NaOCl was used. However, the pH values were very close for the different groups. Hydroxyl ion diffusion up to the external root surface did not exceed the pH value of 8.5, and in the hollow passage of the canal, the pH was higher than 12.

CONCLUSIONS

Hydroxyl ion diffusion of calcium hydroxide paste through the dentinal tubules up to the external root surface allows minimal alkalinization of this surface, and it is greater when using NaOCl with surfactant during biomechanical preparation.

Effects of newly-developed retrograde filling material on osteoblastic differentiation in vitro

The aim of this study was to compare chemical properties and bioactivities of with mineral trioxide aggregate (MTA) and EndoSequence Root Repair Material (ERRM). After setting, surfaces of test materials were observed by scanning electron microscope (SEM). The pH and cell viability of materials were tested. Osteoblastic differentiation and alkaline phosphatase (ALP) activity were measured by quantitative real-time PCR and ALP staining. MTA showed spindle-shaped crystals while ERRM showed round-shaped crystals of various sizes. ERRM presented lower pH than MTA. Both materials showed good cell viabilities compared to the control. Expression levels of osteoblastic genes and ALP staining were increased significantly (p<0.05) in ERRM and MTA groups compared to those in the control group. In conclusion, ERRM and MTA both had effects on osteoblastic differentiation. Therefore, ERRM can be used as a desirable alternative to MTA for root-end filling material.

Influence of chlorhexidine and zinc oxide in calcium hydroxide pastes on pH changes in external root surface

The objective of this study was to assess the influence of chlorhexidine (liquid and gel) and zinc oxide in calcium hydroxide (CH) pastes on root pH in simulated external resorption. One hundred human anterior teeth with a single root canal were selected. After decoronation and root canal instrumentation, the specimens were divided into 4 experimental groups and 1 control group (without intracanal paste): CH + saline (CH+S), CH + 2% chlorhexidine liquid (CH+ CHX), CH + 2% chlorhexidine gel (CH+ CHXg), and CH + 2% chlorhexidine gel + zinc oxide (CH+ CHXg+ZnO). pH was measured using a microelectrode at 3 and 24 h, and 1, 2, 3, and 4 weeks after inserting intracanal pastes. Data were analyzed statistically using an ANOVA and Tukey's test (p < 0.05). The CH+CHXg+ZnO group had the highest pH values throughout (p<0.05). The CH+S and CH+ CHX groups had the highest pH values after 1 week and the CH+ CHXg group after 2 weeks. CH+ CHXg maintained the highest pH until the fourth week compared with CH+ CHX (p < 0.05). The control group remained at a neutral pH at all evaluated times. It can be concluded that chlorhexidine solution or gel maintained the alkaline pH of CH, and chlorhexidine gel allowed a slower decrease in pH over time. CH+ CHXg+ZnO showed the highest pH values and was an effective intracanal medication for maintaining alkaline root pH in the area of resorption.

Alkalizing potential and calcium release of residues from intracanal dressing containing calcium hydroxide

Abstract Introduction If the restoration, that seal the root canal from oral environment, failed or solubilize, the intracanal dressing could be partially removed, decreasing the efficiency of calcium hydroxide (CH). Objective To evaluate the alkalizing potential and calcium ions release of intracanal residues from different medications, in different periods. Materials and method Human incisors were endodontically instrumented and randomly divided (n=10). The root canals were filled with: G1⎯Calcium hydroxide (CH); G2⎯CH with 0.4% chlorhexidine digluconate (CHC); G3⎯CH with camphorated paramonochlorophenol and glycerin (HPG); G4⎯CH was maintained during all experiment, as positive control group (PC) and G5⎯ No medication was performed in the negative control group (NC). The specimens were immersed in distilled water for 7 days. The intracanal dressing was removed from the experimental groups using F1 instrument (Protaper). The teeth were stored in distilled water for 24 hours, 7, 14 and 28 days. pH value and calcium ions released were evaluated and the data were submitted to ANOVA one-way and Tukey tests. Result All experimental groups presented lower alkalizing potential and calcium ions release than PC (P<0.05). No significant difference was found among the experimental groups, regardless of the period (P>0.05). Conclusion The alkalizing potential and calcium ions release of residues from different intracanal dressing, in different periods, were similar and lower than the positive control group, that the medication was maintained inside the root canal, encouraging the replacement of intracanal dressing when the restoration fail.

The effect of endodontic treatment using different intracanal medicaments on periodontal attachment level in concurrent endodontic-periodontal lesions: A randomized controlled trial

Aim:

The aim of this study is to evaluate the effect of different intracanal medicaments used during endodontic treatment on periodontal attachment level in concurrent endodontic-periodontal lesions without communication.

Materials and Methods:

Seventy-five teeth with combined endodontic-periodontal lesions were randomly assigned to 3 groups: Test Group I (calcium hydroxide [Ca(OH)₂]), Test Group II (2% chlorhexidine + Ca(OH)₂), and control group (no intracanal medicament). Root canal treatment (RCT) was performed using standard methodology. Teeth of test groups were medicated with respective medicaments for 10 days before obturation. Scaling and root planning was done 1 month after completion of RCT in all the groups. Clinical measurements, including probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were recorded at baseline, 1, 3, and 6 months. Radiographic parameters, including periapical index (PAI) score and alveolar bone level, were measured at baseline and 6 months.

Statistical Analysis:

Data were analyzed using Friedman test, Kruskal–Wallis, and Wilcoxon signed-rank test.

Results:

Significant improvement in PD, CAL, %BOP, and PAI score (P < 0.05) was found in all the three groups from baseline to 6 months. However, there was no significant intergroup difference. No significant difference was observed from baseline to 6 months in marginal bone level within the three groups.

Conclusion:

Endodontic treatment before periodontal therapy results in attachment gain. Intracanal medicaments may not affect the healing of concurrent endodontic-periodontal lesions without communication.

Manejo endodôntico de dentes reimplantados: revisão de literatura

O reimplante dentário destaca-se como um procedimento conservador, sendo a conduta não-protética que pode ser realizada em casos de avulsão, evitando sequelas estéticas, funcionais e psicológicas junto ao paciente. Para controlar os processos reabsortivos que se desencadeiam devido a lesão no ligamento periodontal, o tratamento endodôntico se faz necessário. Objetivo: apresentar uma revisão de literatura sobre o manejo endodôntico de dentes reimplantados, elucidando os aspectos clínicos, radiográficos e fisiológicos envolvidos no processo e, também, confeccionar um guia de consulta para prática clínica. Conclusão: O reimplante dentário auxilia no aspecto psicológico decorrente da perda dentária, sendo a endodontia uma etapa fundamental no processo. Ao final do tratamento Endodôntico de um dente re-implantado, com uso da medicação intracanal adeaquada, a saber hidróxido de cálcio,  espera-se um dente clinicamente assintomático e radiograficamente ausência de sinais de reabsorção e lesão apical. Contudo, o  acompanhamento clínico e radiográfico do paciente deve ser feito por pelo menos cinco anos.

Laser/LED phototherapy on the repair of tibial fracture treated with wire osteosynthesis evaluated by Raman spectroscopy

The aim of the present study was to assess, by means of Raman spectroscopy, the repair of complete surgical tibial fractures fixed with wire osteosynthesis (WO) treated or not with infrared laser (λ780 nm) or infrared light emitting diode (LED) (λ850 ± 10 nm) lights, 142.8 J/cm² per treatment, associated or not to the use of mineral trioxide aggregate (MTA) cement. Surgical tibial fractures were created on 18 rabbits, and all fractures were fixed with WO and some groups were grafted with MTA. Irradiated groups received lights at every other day during 15 days, and all animals were sacrificed after 30 days, being the tibia removed. The results showed that only irradiation with either laser or LED influenced the peaks of phosphate hydroxyapatite (~ 960 cm^-1). Collagen (~ 1450 cm^-1) and carbonated hydroxyapatite (~ 1070 cm^-1) peaks were influenced by both the use of MTA and the irradiation with either laser or LED. It is concluded that the use of either laser or LED phototherapy associated to MTA cement was efficacious on improving the repair of complete tibial fractures treated with wire osteosynthesis by increasing the synthesis of collagen matrix and creating a scaffold of calcium carbonate (carbonated hydroxyapatite-like) and the subsequent deposition of phosphate hydroxyapatite.

Preference and usage of intracanal medications during endodontic treatment

Objectives:

To investigate the preferences of general dental practitioners (GDPs) and endodontists in using endodontic intra-canal medications (ICMs).

Methods:

This observational and descriptive study was conducted in 2014 in the western province of Saudi Arabia. Following ethical clearance and 2 pilot studies, a web-based questionnaire was electronically sent to 375 randomly and systematically selected GDPs and all endodontists in the western province (n=49). An accompanying e-mail explained the study’s aims and confirmed that the data yielded would remain confidential. The responses were collected, and the data was analyzed using the Chi-square test at p=0.05.

Results:

Significantly, the highest proportion of respondents (53.7%) reported disinfection of the root canals as the main function of ICMs. Calcium hydroxide (CH) was the preferred material of the majority of those who used the same ICM in all cases (85.7%). While the vast majority of all endodontists (87.5%) used CH after pulp extirpation, 48.5% of GDPs used formocresol (p<0.001). Almost 30% of those who used ICMs after pulp extirpation did not do so after cleaning and shaping of vital cases. Most endodontists used CH (62.5%) and antibiotics (37.5%) in necrotic pulp cases without apical lesions, which were significantly greater than those of GDPs who did the same (43.8% and 17.2%).

Conclusions:

Participants were aware that the main function of ICMs is disinfection of the root canal system. However, it is clear that GDPs should reduce their reliance on phenol- and formaldehyde-based medications. There was a distinct trend toward the use of ICMs, especially CH, in necrotic pulp cases.

Effect of Exposed Surface Area, Volume and Environmental pH on the Calcium Ion Release of Three Commercially Available Tricalcium Silicate Based Dental Cements

Tricalcium silicate cements (TSC) are used in dental traumatology and endodontics for their bioactivity which is mostly attributed to formation of calcium hydroxide during TSC hydration and its subsequent release of calcium and hydroxide ions. The aim of this study was to determine the effect of volume (Vol), exposed surface area (ESA) and pH of surrounding medium on calcium ion release. Three commercially available hydraulic alkaline dental cements were mixed and condensed into cylindrical tubes of varying length and diameter (n = 6/group). For the effect of ESA and Vol, tubes were immersed in 10 mL of deionized water. To analyze the effect of environmental pH, the tubes were randomly immersed in 10 mL of buffer solutions with varying pH (10.4, 7.4 or 4.4). The solutions were collected and renewed at various time intervals. pH and/or calcium ion release was measured using a pH glass electrode and atomic absorption spectrophotometer respectively. The change of pH, short-term calcium ion release and rate at which calcium ion release reaches maximum were dependent on ESA (p < 0.05) while maximum calcium ion release was dependent on Vol of TSC (p < 0.05). Maximum calcium ion release was significantly higher in acidic solution followed by neutral and alkaline solution (p < 0.05).

Nonsurgical Management of a Large Periapical Lesion: A Case Report

This case report describes the non-surgical management of a large cyst-like periapical lesion in the mandible of a 16-year-old female with the chief complaint of periodic swelling and pus drainage from the mandibular anterior region gingivae with no history of pain and traumatic accident in this area. Both mandibular central incisors had extensive caries. Root canals of both mandibular central incisors were filled with calcium hydroxide. After 10 days, endodontic therapy was carried out on both teeth. Clinical and radiographic re-evaluations at 3 and 12 months revealed progressing bone healing. This case report shows that appropriate diagnosis in combination with root canal treatment as a conservative non-surgical approach can lead to complete healing of large lesions without invasive treatments.

Histologic evaluation of the effect of mineral trioxide aggregate-Fillapex as a root canal sealer in rat teeth submitted to late replantation

OBJECTIVE

This study aims to analyze the effect of new root canal based silicate cement, in rat teeth after late replantation, comparing with calcium hydroxide (CH) in preventing tooth root resorption.

MATERIALS AND METHODS

The study group included 16 Wistar rats in which the upper right central incisors were extracted and were left on a worktable for 60 min, simulating a case of tooth avulsion, after had been anesthetized. One group, (Group I), the canals were filled with CH past, before replantation. The second groups of teeth, (Group II), the canals were filled with mineral trioxide aggregate-Fillapex (MTAF). After removal, the blood clot of the socket, with saline solution irrigation, the teeth were replanted into their original socket, and splinted with silk 3/0. The rats were sacrificed 8 weeks after replantation and the specimens were prepared for histologic and histomorphometric analyses. The areas of inflammatory and replacement resorptions were selected and quantified. These data for each group of teeth were evaluated and analyzed using the Mann-Whitney test (P = 0.05).

RESULT AND CONCLUSION

All the replanted teeth in both groups survived. Although root canal filled with MTAF provide better results than with CH past concerning inflammatory and replacement resorption, there was no statistical difference (P = 0.527).