Bromelain-based endodontic irrigant: preparation, properties, and biocompatibility: An in-vitro study

The aim of the study was to determine the properties, efficacy and biocompatibility of combining bromelain enzyme, chlorohexidine and EDTA (BCE) to create a novel endodontic irrigant. Fourier transform infrared spectrometry was performed to confirm the stability of the BCE and direct contact inhibition test was performed to determine antibacterial action. Baseline pH and surface tension of irrigants was compared with determine stability. Subcutaneous injection to dorsal skin of rabbits was graded for presence of inflammation, oedema, granulation and fibrosis. BCE caused less overall irritation, less oedematous and was earlier to heal than 2.5% NaOCl. The pH stability of BCE was also superior to 2.5% NaOCl. A one-way ANOVA test was performed for the direct contact inhibition and microleakage test. A significant difference was determined (p ≤ 0.05) between BCE and 2.5% NaOCl for antibacterial action. BCE irrigant is effective in preparing dentinal surfaces for root canal without adverse effects and promising longevity.

The Effect of Different Immersion Media, Polymerization Modes, and Brushing on the Color Stability of Different Composite Resins

This in vitro study investigated color stability of two photo-polymerized nano-filled and nano-hybrid composite resins in different polymerization modes immersed in different staining solutions before and after brushing. Disc-shaped specimens (n = 120) were prepared from two composite resins based on filler particle size: nano-filled (Filtek Z350, shade A1, 3M ESPE) and nano-hybrid (Spectra ST-HV, shade A1, Dentsply Sirona) composite resins (n = 60 per composite type). Specimens of each resin type were photopolymerized using the following polymerization modes: LED conventional, ramp, and pulse (n = 20 specimens per resin type and LED mode). After preparation, baseline color of the specimens was evaluated using a spectrophotometer (Easyshade V, VITA), and color change was evaluated using the CIE L*a*b* formula. Specimens were soaked in distilled water for 4 weeks in separate containers. The specimens from each polymerization-mode group were separated into two groups of 10 specimens; one group was stored in tea and the other group was stored in cola, each 1 hour daily for 4 weeks. After 4 weeks, the color was measured again. The specimens were brushed for 2 minutes under 200-g weight using an electronically powered toothbrush on the polymerized side of the specimen. The color was reevaluated immediately after brushing. Color-difference data (ΔE) between groups were analyzed by one-way analysis of variance for main comparison and by independent t test for color change after brushing. Nano-filled composite resin was more color-stable than nano-hybrid composite resin (P < .001), regardless of the staining media. For both composite resin types, the conventional polymerization method produced a more color-stable result (P < .0001). ΔE after brushing was reduced significantly (P < .0001). Both staining solutions have significant effects on color change, with tea staining more than cola (P < .0001). Nanofilled composite resin had greater color stability than nano-hybrid composite resin after immersion in staining solutions. Polymerization mode influences the color stability of both composite resin types. Int J Periodontics Restorative Dent 2023;43:247-255. doi: 10.11607/prd.6427.

Wear and Color Stability of Preheated Bulk-fill and Conventional Resin Composites

OBJECTIVES

Bulk-fill resin composite is commonly used in direct restorations. It is recommended that the high-viscosity version of these materials be preheated to improve flowability and adaptability. It is unknown what effects preheating (PH) might have on the wear resistance and color stability of these resin composites. This study compared the wear and color stability of high-viscosity bulk-fill and conventional resin composites with and without PH, using the CIEDE2000 formula.

METHODS AND MATERIALS

Thirty-two disc-shaped specimens (n=16, 10×3 mm) were prepared with Filtek One Bulk Fill Restorative (FOBFR; 3M ESPE) and Filtek Supreme Ultra (FSU, 3M ESPE) to determine wear. Each group was divided into subgroups based on preparation conditions, that is, PH and room temperature (RT) (n=8). Thermomechanical fatigue was applied to specimens, and volumetric material loss was calculated using a laser scanner (LAS-20, SD Mechatronik, Feldkirchen-Westerham, Germany) and three-dimensional imaging software (Geomagic, 3D Systems, Rock Hill, SC, USA). An additional 124 disc-shaped specimens (n=64, 10×1 mm) were prepared with FOBFR and FSU, and subgroups were formed based on preparation conditions (PH and RT, n=32). Specimens were aged for 14 days in coffee, grape juice, distilled water, and thermocycling (20,000 cycles, 5°C-55°C). To determine color change, the lightness (L), chroma (C), and hue (H) values were measured at baseline and after 14 days using the CIEDE2000 formula. All data were statistically analyzed, and a 95% significance level was set.

RESULTS

In both the PH and RT groups, FSU exhibited greater wear than FOBFR (p<0.05). Both materials were subjected to increased wear as a result of PH. After aging, a significant difference in color change was observed (p<0.05) when controlling for time and resin composite type, except for deionized water and thermocycling (p>0.05). PH had no effect on the color stability of the resin composite at any time (p<0.05).

CONCLUSION

The high-viscosity bulk-fill resin composite displayed superior wear resistance and similar color stability compared with its conventional counterpart. PH resin composite may increase its susceptibility to wear and has no effect on its color stability.

Debridement Ability of TruNatomy, S-One Plus, and Other Single File Systems

BACKGROUND: Rotary nickel titanium instrument are an essential part of endodontic treatment, it is important to compare the root canal cleaning ability of these instruments. AIM: This study aimed to compare the amount of smear and debris layer remained following the use of four rotary instruments with an irrigant solution: TruNatomy (TRN), Protaper Next (PTN), S-One Plus and Wave One Gold (WOG). METHODS: A total of 80 extracted mandibular premolars were used and decoronated to the cemento-enamel junction. The roots were randomly divided into four groups of 20 specimens each. The roots were instrumented according to the manufacturer’s instructions of each file, the root canals were irrigated with sodium hypochlorite (NaOCl), Ethylene-diaminete-traacetic acid (EDTA) and Normal saline with each file use, two grooves were prepared on the buccal and lingual surfaces by disc to facilitate vertical splitting with a chisel. The presence of the smear layer and the debris layer were evaluated under Scanning Electron Microscope. RESULTS: Trunatomy remove the smear layer substantially better than PTN and S-one Plus. Wave one gold significantly removes smear layer better PTN. The amount of debris remained in TruNatomy group was significantly lower than other groups, all experimental files significantly removes the smear layer and debris layer better in the middle and coronal thirds compared to apical third. CONCLUSION: TruNatomy showed better cleaning capacity than all other experimental groups and all experimental groups demonstrated better cleanliness at the coronal and middle third of the roots.

Antibacterial Efficacy of Different Herbal Based Irrigant Solutions in Deciduous Teeth

Introduction: Endodontic infection requires the successful removal of microorganisms from the root canal system. The most effective irrigant solution is sodium hypochlorite, but possible problems due to its toxicity require the look for new alternatives. Constant increases in antibiotic resistance and side-effects caused by chemical irrigation have shifted research towards the production of herbal alternatives, especially in paediatric dentistry. Aim: To evaluate and compare the antibacterial efficacy of miswak, green tea, chamomile and 0.5% NaOCl as an endodontic irrigants against Enterococcus faecalis in primary root canals. Materials and Methods: The in-vitro study was conducted at the Department of Conservative Dentistry and Department of Microbiology, College of Dentistry, University of Duhok from January 2020 till June 2020. Seventy five freshly extracted intact human mandibular primary molars were decoronated at Cemento-Enamel Junction (CEJ) and distal roots were separated and biomechanically prepared up to F3 Protaper file and stored in normal saline. The specimens were inoculated with Enterococccus faecalis suspension and incubated for 72 hours. Specimens were divided into five groups containing fifteen teeth each (n=15). Freshly prepared alcoholic extracts of miswak, green tea and chamomile were used as an irrigant solution against E.faecalis compared to NaOCl as positive control and normal saline as negative control. Swabs were collected using F3 protaper paper points. The number of colonies was counted in suitable plate under good illumination and manual lens for magnification. Statistical analysis was performed by using Kruskal-Wallis one-way Analysis and Student-Newman-Keuls Method. Statistical Package for the Social Sciences (SPSS) version 26.0 was used. The p-values more than 0.05 were considered as statistically non significant. Results: Green Tea, among the herbal experimental groups, had the most effective antibacterial effect against E.faecalis. No significant statistical difference was detected between green tea (p=0.272) and NaOCl; however, there was significant difference between miswak, chamomile and NaOCl as well as between the rest herbal experimental groups and normal saline. Conclusion: NaOCl remains the gold standard as irrigant in primary teeth. Green tea extract may help in reducing E.faecalis inside the canals of primary teeth. Good efficacy against E.faecalis was also shown by Miswak and chamomile however the results obtained were not significant when compared with NaOCl.