Efficacy of calcium hydroxide-loaded poly(lactic-co-glycolic acid) biodegradable nanoparticles as an intracanal medicament against endodontopathogenic microorganisms in a multi-species biofilm model

This study aimed to evaluate the antimicrobial activity of calcium hydroxide-loaded poly(lactic-co-glycolic acid) nanoparticles (CH-loaded PLGA NPs) on multi-species biofilms. Human root blocks were prepared (n = 40), and multi-species suspensions of Candida albicans, Enterococcus faecalis and Streptococcus gordonii were incubated within the root canals for 21 days. Canals (n = 10/group) were then medicated with saline solution (negative control), chlorhexidine (positive control), calcium hydroxide and CH-loaded PLGA NPs for 7 days. Samples taken from the 0.1 mm root canal dentin were collected, and cell growth was detected by culture on BHI agar. The viable cell count of the Ca(OH)2, chlorhexidine gel and CH-loaded PLGA NPs group was significantly lower than the normal saline group (p < 0.001). CH-loaded PLGA NPs demonstrated a significant lower viable cell than Ca(OH)2 (p < 0.001); it has potential as a medicament for endodontic therapy.

Association between intracanal medicament radiopacity and streak artifact production using cone-beam computed tomography: a laboratory study

INTRODUCTION

This study aimed to calculate the correlation between the radiopacity levels of various intracanal medicaments and radiolucent streak formation using cone-beam computed tomography (CBCT).

METHODS

7 commercially-available intracanal medicaments were tested, which contained different amounts of radiopacifier [Consepsis, Ca(OH)₂, UltraCal XS, Calmix, Odontopaste, Odontocide, and Diapex Plus]. Their radiopacity levels were measured according to the ISO 13116 testing standards (mmAl). Subsequently, the medicaments were placed in 3 canals of radiopaque artificial printed maxillary molars (n=15 roots per medicament), leaving the second mesiobuccal canal empty. CBCT imaging was carried out using an Orthophos SL 3D scanner under recommended manufacturer exposure settings. Radiopaque streak formation was assessed by a calibrated examiner using a previously published grading system (0-3). The Kruskal-Wallis and Mann-Whitney U tests with and without Bonferroni correction were used to compare radiopacity levels and radiopaque streak scores for the medicaments. Their relationship was assessed using the Pearson correlation coefficient. The level of significance was set as (α=0.05).

RESULTS

Diapex plus presented with the highest radiopacity levels (4.98±0.01) and radiopaque streak scores [middle third (2.8±0.18); apical third (2.73±0.43)]; which was similar to UltraCal XS's radiopaque streak scores [middle third (2.8±0.92); apical third (2.73±0.77)]. Consepsis had the lowest radiopacity levels (0.12±0.05), followed by Odontocide (0.60±0.05). Consepsis and Ca(OH)₂ were scored 0 for artifacts in all roots at all levels. A high positive correlation (R=0.95) was found between radiopacity and streak formation.

CONCLUSIONS

The radiopacity of intracanal medicaments varies and strongly correlates with the formation of radiolucent streak artifacts during CBCT.

A critical analysis of research methods and experimental models to study intracanal medicaments

In order to ensure predictable decontamination of the root canal system, chemo-mechanical preparation of the root canal space is sometimes supplemented with the use of intracanal medication. As microbial control of the root canal space is fundamental to the resolution of apical periodontitis, root canal disinfection strategies haven been researched intensively. The use of intracanal medication as a supplementary step to the chemo-mechanical preparation of the root canal space is one of them. Because of the costs and limitations of clinical research it is relevant and common practice to first evaluate alternative or new root canal disinfection modalities in laboratory studies. This involves the simulation of a root canal infection in a laboratory model, on which different disinfection strategies can be tested. When modelling the infected root canal, different levels of infection can be discriminated: suspended bacteria, microbial biofilms and infected dentine. This review describes the experimental models associated with these infection levels and critically appraises their value and methodological details. Suggestions for relevant research methods and experimental models are given, as well as some good practices for laboratory-based microbiological studies.

Homeopathic consideration for resistant endodontic bacteria Enterococcus faecalis: An in vitro comparative disc diffusion study

Background:

Homeopathy is one of the commonly used systems of complementary or alternative medicine. The present study was conducted with an aim to compare the antibacterial efficacy of two commonly used homeopathic medicaments acid benzoicum 30C (SBL Pvt Ltd) and silicea 6C (SBL Pvt Ltd) with that of calcium hydroxide (Deepti Ltd) as intracanal medicament against Enterococcus faecalis (ATCC-29212).

Materials and Methods:

The test organism used for the study was E. faecalis. Petri plates with 20 ml of sheep blood agar were inoculated with 0.1 ml of the microbial suspensions. The medicaments to be tested for antimicrobial efficacy against E. faecalis were divided into three groups: Group A (acid benzoicum), Group B (silicea), and Group C (calcium hydroxide). The antimicrobial activity of each medicament was measured and expressed in terms of the mean of the diameter of zone of inhibition (in mm) produced by each extract at the end of the incubation period. ANOVA and Tukey's honestly-significant difference posthoc test were used for the intergroup comparison. P < 0.05 was considered statistically significant.

Results:

Group A (acid benzoicum) showed the maximum zone of inhibition against Gram-positive E. faecalis (17.2 ± 0.65), and the difference between the groups related to the antibacterial activity was highly significant (P < 0.001). A statistically significant difference was observed between the three groups on the intergroup comparison (P < 0.001).

Conclusion:

In the present in vitro study, antimicrobial activity of the acid benzoicum extract was the highest followed by silicea extract and then calcium hydroxide.

Influence of calcium hydroxide on the post-treatment pain in Endodontics: A systematic review

Introduction:

Pain of endodontic origin has been a major concern to the patients and the clinicians for many years. Post-operative pain is associated with inflammation in the periradicular tissues caused by irritants egressing from root canal during treatment. It has been suggested that calcium hydroxide intra-canal medicament has pain-preventive properties because of its anti-microbial or tissue altering effects. Some dispute this and reasoned that calcium hydroxide may initiate or increase pain by inducing or increasing inflammation.

Objective:

To evaluate the effectiveness of calcium hydroxide in reducing the post-treatment pain when used as an intra-canal medicament

Materials and Methods:

The following databases were searched: PubMed CENTRAL (until July 2013), MEDLINE, and Cochrane Database of Systematic Reviews. Bibliographies of clinical studies and reviews identified in the electronic search were analyzed for studies published outside the electronically searched journals. The primary outcome measure was to evaluate the post-treatment pain reduction when calcium hydroxide is used as an intra-canal medicament in patients undergoing root canal therapy.

Results:

The reviews found some clinical evidence that calcium hydroxide is not very effective in reducing post-treatment pain when it is used alone, but its effectiveness can be increased when used in combination with other medicaments like chlorhexidine and camphorated monochlorophenol (CMCP).

Conclusion:

Even though calcium hydroxide is one of the most widely used intra-canal medicament due to its anti-microbial properties, there is no clear evidence of its effect on the post-treatment pain after the chemo-mechanical root canal preparation.

Anti-microbial efficiency of silver diamine fluoride as an endodontic medicament - An ex vivo study

CONTEXT

Antisepsis achieved through appropriate use of irrigants is essential for endodontic success. Identification of newer anti-bacterial agents gives alternatives to clean the canal as eradication of the infection prior to obturation does affect prognosis.

OBJECTIVE

Comparison of the anti-bacterial action of 3.8% silver diamine fluoride and 2% chlorhexidine gluconate against Enterococcus faecalis in root canals.

MATERIALS AND METHODS

Forty-four single-rooted teeth were decoronated, and the root section was enlarged with peeso-reamer (No: 3) to standardize length and diameter. The samples were then autoclaved and divided into two study groups and two control groups. Enterococcus faecalis ATCC 29212 was inoculated into all test samples for 72 hours. The samples were enlarged with peeso-reamer (No: 5) after placement of respective medicament for 24 hours. Shavings were collected and inoculated on Brain Heart Infusion agar for 24 hrs to measure the colony forming units.

RESULTS

Both 3.8% silver diamine fluoride and 2% chlorhexidine showed a superior capacity to sterilize the root canals than control groups.

CONCLUSION

The use of silver diamine fluoride as an endodontic irrigant is feasible as it can effectively remove the microbes present in the canal and circumpulpal dentin.