The Effect of Pulpotomy Base Material on Bacterial Penetration and Proliferation for Pulpotomized Primary Molar Teeth: A Confocal Laser Scanning Microscopy Study

Abstract

Introduction: the study aimed to evaluate Enterococcus Faecalis colonization in the pulp chamber in pulpotomized extracted human teeth filled by different pulpotomy base materials (PBMs), using confocal laser scanning microscopy (CLSM). Study design: Cavity preparations were made in 70 extracted primary molars. The pulp chambers were filled using either Intermediate restorative material (IRM), Mineral Trioxide Aggregate (MTA) or Glass ionomer (GI). Twenty-five teeth served controls. The specimens were sterilized, and coronally filled with bacterial suspension for 21 days. The specimens were cut through the furcation area, stained using LIVE/DEAD BacLight Bacterial Viability Kit and evaluated using CLSM. Results: The extent of fluorescent staining was larger in the GI group, compared to the IRM and MTA groups, and larger in the IRM group compared to the MTA group (P<0.05). The minimal and maximal bacterial penetration depths into the dentinal tubules were 55 and 695μm, respectively (mean 310μm), without differences between the materials (GI, IRM, MTA, p>0.05). The ratio of live bacteria to dead bacteria within the evaluated areas was higher in the GI group compared to the IRM and the MTA groups, and higher in the IRM group compared to the MTA group (P<0.05). There were no differences between the mesial, distal and apical parts in any of the evaluations (p>0.05). Conclusions: bacteria colonize the interface between the PBM and dentin and penetrate deeply into the dentinal tubules. The extent and the vitality of the colonized bacteria may be affected by the type of PBM.

Bacterial Colonization and Proliferation in Primary Molars following the Use of the Hall Technique: A Confocal Laser Scanning Microscopy Study

“…E. faecalis was chosen because this species exist in the normal oral flora in humans, is frequently found in mixed infections with other aerobes and facultative anaerobes, and does not form endospores [ 25 , 26 ]. E. faecalis also plays an essential role in bacterial biofilm formation and therefore is considered an appropriate model for testing novel treatments [ 14 , 27 , 28 , 29 , 30 ].…”

“…Additionally, CLSM can visualize living cells and tissues in real time, providing valuable information for research on biological processes in the oral cavity, such as tooth development, wound healing, and disease progression. Overall, CLSM has the potential to enhance the understanding of dental biology and material science significantly, making it a valuable tool for dental research [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. In our study, CLSM provided direct and quantifiable information about the presence and distribution of live and dead E. faecalis bacteria inside the dentinal tubules [ 31 ].…”

“…Previous studies that evaluated the effectiveness of various restorative techniques comprehensively assessed the microleakage of SSCs using various laboratory and clinical methods. These included the dye penetration test, in which a dye is applied to the tooth, and the depth of dye penetration is measured to evaluate microleakage; high-power electron microscopy to observe the interface between the tooth and the restoration; the fluoride leakage test which uses a solution containing fluoride to measure the amount of fluoride leaking from the restoration; and the radioisotope leakage test, in which radioactive material is placed on the restoration and the amount of radioactivity leaking from the tooth is measured [ 14 ]. Several other microscopic techniques have been used to assess the bacterial colonization of dentin, including stereomicroscopy, scanning electron microscopy, and transmission electron microscopy; however, these methods serve mainly for descriptive purposes as they are indirect, not qualitative, and cannot evaluate the viability of bacteria [ 15 , 16 , 17 ].…”

Comparative Analysis of Bacterial Colonization in Simulated Vertical Root Fractures of Root Canals Filled with Various Obturation Materials using Confocal Laser Scanning Microscopy

“…CLSM is a valuable modality of choice alongside more traditional SEM and PCR-based techniques to identify viable bacteria in dentinal tubules [10,[12][13][14][15]. Importantly, using CLSM with the live/dead staining method allows us to assess the extent of contamination and vitality of bacteria in the dentinal tubules [10,[12][13][14][15]. No study has used CLSM to evaluate the bacterial colonization in VRF of extracted human teeth lled with different materials.…”

“…Confocal laser scanning microscopy (CLSM) has been used in previous studies to examine the nature of bacterial colonization in VRFs [10,[12][13][14][15]. However, there is still a need to investigate the relationship between the type of intracanal lling material and the bacterial colonization of VRF.…”