scholarly journals The Invasion of Bacterial Biofilms into the Dentinal Tubules of Extracted Teeth Retrofilled with Fluorescently Labeled Retrograde Filling Materials

2020 ◽  
Vol 10 (19) ◽  
pp. 6996
Author(s):  
Eyal Rosen ◽  
Shlomo Elbahary ◽  
Sohad Haj-Yahya ◽  
Lotof Jammal ◽  
Hagay Shemesh ◽  
...  

In this study, we evaluated the invasion of bacteria into the dentinal tubules of retrofilled extracted human teeth, and the influence of different fluorescently labeled retrograde filling materials on the bacterial invasion and viability, by means of confocal laser scanning microscopy (CLSM). The root apices of extracted teeth were cut, prepared, and filled retrogradely using either intermediate restorative material (IRM), mineral trioxide aggregate (MTA), or Biodentine. The roots were filled with Enterococcus faecalis bacteria from their coronal part for 21 days. Then, 3-mm-long apical segments were cut to get root axial slices, and the bacteria were fluorescently stained and evaluated by CLSM. Bacterial penetration into the dentinal tubules favored the bucco-lingual directions. The filling materials penetrated up to 957 µm into the tubuli, and the bacteria, up to 1480 µm (means: 130 and 167 μm, respectively). Biodentine fillings penetrated less and the associated bacteria penetrated deeper into the tubuli compared to MTA or IRM (p = 0.004). Deeper filling penetration was associated with shallower penetration of both dead and live, or live alone, bacteria (p = 0.015). In conclusion, the current study enables better understanding of the microbiological–pathological course after endodontic surgical procedures. It was found that even with retrograde fillings, bacteria invade deep into the dental tubules, where deeper filling penetration prevents deeper penetration of the bacteria and adversely affects the viability of the bacteria.

2021 ◽  
Vol 11 (8) ◽  
pp. 3403
Author(s):  
Shlomo Elbahary ◽  
Sohad Haj Yahya ◽  
Cemre Koç ◽  
Hagay Shemesh ◽  
Eyal Rosen ◽  
...  

Following furcal perforation, bacteria may colonize the defect and cause inflammation and periodontal destruction. This study used confocal laser scanning microscopy (CLSM) to evaluate Enterococcus faecalis colonization and proliferation in furcal perforations repaired with different materials. Furcal perforations created in 55 extracted human mandibular molars were repaired using either MTA-Angelus, Endocem, or Biodentine and coronally subjected to E. faecalis suspension for 21 days. The specimens were then stained using a LIVE/DEAD Viability Kit and visualized by CLSM. The minimum and maximum depths of bacterial penetration into the dentinal tubules were 159 and 1790 μM, respectively, with a mean of 713 μM. There were significantly more live than dead bacteria inside the dentinal tubules (p = 0.0023) in all groups, and all three repair materials exhibited a similarly sized stained area (p = 0.083). However, there were significant differences in the numbers of dead bacteria at the circumference of the perforation defect (p = 0.0041), with a significantly higher ratio of live to dead bacteria in the MTA-Angelus group (p = 0.001). Following perforation repair, bacteria may colonize the interface between the repair material and dentin and may penetrate through the dentinal tubules. The type of repair material has a significant effect on the viability of the colonizing bacteria.


2020 ◽  
Vol 10 (8) ◽  
pp. 761
Author(s):  
Narcisa Mandras ◽  
Mario Alovisi ◽  
Janira Roana ◽  
Paola Crosasso ◽  
Anna Luganini ◽  
...  

Confocal laser scanning microscopy (CLSM) was used to evaluate the antibacterial effect and depth of action of a novel clarithromycin-containing triple antibiotic mixture, which was proposed for root canal disinfection in dental pulp regeneration. A previous study reported that this mixture had no tooth discoloration effects in vitro. After infection with Enterococcus faecalis for 3 weeks, the dentinal tubules in the cylindrical root specimens were exposed to different antibiotic mixtures: ciprofloxacin, metronidazole and minocycline (3-MIX); ciprofloxacin, metronidazole and clarithromycin (3-MIXC) and ciprofloxacin and metronidazole (2-MIX). Each antibiotic formulation was mixed with macrogol (MG) or hyaluronic acid (HA) vehicles. CLSM and viability staining were used to quantitatively analyze the mean depth of the antibacterial effect and the proportions of dead and live bacteria inside the dentinal tubules. The 3-MIX and 3-MIXC demonstrated a similar depth of action. The mean proportion of dead bacteria was similar in the 3-MIX and 3-MIXC groups, and both were statistically higher than that of 2-MIX (p = 0.014). Each antibiotic mixture showed a higher bactericidal efficacy if conveyed with HA, compared to MG (3-MIX, p = 0.019; 3-MIXC, p = 0.013 and 2-MIX, p = 0.0125). The depth of action and the antibacterial efficacy of 3-MIXC seemed comparable with 3-MIX.


2020 ◽  
Author(s):  
Abhishek Parolia ◽  
Haresh Kumar Kumar ◽  
Srinivasan Ramamurthy ◽  
Allan Pau

Abstract Background To determine the antibacterial effect of chitosan-propolis nanoparticle (CPN) as an intracanal medicament against Enterococcus faecalis biofilm in root canal. Methods 240 extracted human teeth were sectioned to obtain 6mm of the middle third of the root. The root canal was enlarged to an internal diameter of 0.9mm. The specimens were inoculated with E. faecalis for 21 days. Following this, specimens were randomly divided into eight groups ( n=30 ) according to the intracanal medicament placed: group I: saline, groupII: chitosan, group III: propolis100 µg/ml (P100), group IV: propolis 250 µg/ml (P250), group V: chitosan-propolis nanoparticle 100µg/ml (CPN100), group VI: chitosan-propolis nanoparticle 250 µg/ml (CPN250), group VII: calcium hydroxide(CH) and group VIII: 2% chlorhexidine (CHX) gel. Dentine shavings were collected at 200 and 400 μm depths, and total numbers of CFUs were determined at the end of day one, three and seven. The non-parametric Kruskal Wallis and Mann-Whitney tests were used to compare the differences in reduction of CFUs between all groups and probability values of P < 0.05 were set as the reference for statistically significant results. The scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM) were also performed after exposure to CPNs. The effectiveness of CPNs were also evaluated against E. faecalis isolated obtained from patients having failed root canal treatment. Results Reduction in the number of colony‐forming units was statistically significant in all groups compared to saline (p <.05). On day one and three, at 200 and 400-μm, CPN250 showed significant reduction of CFUs compared to all other groups (p <.05), while CPN100 was significantly better than other groups (p <.05) except CPN250 and CHX. On day seven, at 200-μm CPN250 showed significant reduction of CFUs compared to all other groups (p <.05) except CPN100 and CHX, while at 400 μm CPN250 showed similar effectiveness as CPN100, CH and CHX. SEM and CLSM images also showed the maximum reduction of E. faecalis with CPN250. Conclusion CPN250 was the most effective in reducing E. faecalis colonies on day one, three at both depths and at day seven CPN250 was equally effective as CPN100 and CHX.


2019 ◽  
Vol 30 (6) ◽  
pp. 555-562
Author(s):  
Maybell Tedesco ◽  
Marcelo Carvalho Chain ◽  
Wilson Tadeu Felippe ◽  
Ana Maria Hecke Alves ◽  
Lucas da Fonseca Roberti Garcia ◽  
...  

Abstract This study correlated the bond strength (BS) and dentin penetration of different sealers by push-out test and Confocal Laser Scanning Microscopy (CLSM) analysis. Forty-five root canals were prepared according to the crown-down technique and filled with gutta-percha associated to the following sealers (n=15): Endofill, AH Plus and MTA Fillapex. Five canals of each group were filled with the sealers added with 0.1% Rhodamine B dye. Next, the specimens were transversely sectioned and submitted to the push-out test (n=10) and CLSM analysis (n=5). The BS data showed the following means (MPa) and standard deviation: AH Plus (4.17±1.86); MTA Fillapex (3.13±1.96) and Endofill (2.10±1.03). Statistical analysis (two-way ANOVA, α=0.05) showed significant difference among sealers (p<0.001) and root canal thirds (p<0.001). The BS results of Endofill and MTA Fillapex were statistically similar (p>0.05), however, they were statistically different from AH Plus (p<0.001). The regional analysis of BS showed similarity between middle and apical thirds (p>0.05), and both were different from coronal portion (p<0.001). CLSM analysis verified tags formation in all groups and higher penetration of the specimens filled with AH Plus (p<0.05). The Kendall test (correlation between BS to dentin and sealer penetration into dentinal tubules) and the Pearson test (between failures pattern and sealer penetration into dentinal tubules) did not show correlation between the variables evaluated for all the tested sealers (p>0.05). AH Plus group had higher BS to dentin, and deeper tags formation than the other sealers. There was no significant correlation between BS and intratubular penetration of the tested sealers.


Endodontology ◽  
2021 ◽  
Vol 33 (2) ◽  
pp. 92
Author(s):  
Sanjana Khullar ◽  
Anurag Aggarwal ◽  
Harleen Chhina ◽  
Tamanpreet Kaur ◽  
Mehak Sharma ◽  
...  

1995 ◽  
Vol 9 (4) ◽  
pp. 355-362 ◽  
Author(s):  
H. Duschner ◽  
C.-P. Ernst ◽  
H. Götz ◽  
M. Rauscher

Migration of trace amounts of elements and structural changes characterize the interface between immiscible substances. The contact zone among filling materials, saliva, and the cavity wall has the additional function of preventing the progress of leakage and subsequent caries. Difficulties in chemically and structurally analyzing the gradients of composition in an interface of microscopic dimensions characterize the experimental situation. The use of advanced techniques of instrumental micro-analysis and techniques of micro-visualization is our approach to the problem. With confocal laser scanning microscopy (CLSM), effects of the components of the filling material on the structure of the cavity wall can be visualized non-destructively. Surface analysis with electron spectroscopy (XPS) and micro-spot analysis with laser mass analysis (LASMA) give the information on changes of the elemental composition of the cavity wall. The effects of the filling materials on the structure of enamel are correlated with the pre-treatment of the cavity wall. XPS and LASMA give evidence that fluoride does not migrate into the enamel of the cavity wall.


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