Impact of Adjunctive Laser Irradiation on the Bacterial Load of Dental Root Canals: A Randomized Controlled Clinical Trial

Bactericidal Effect of Different Photochemical-Based Therapy Options on Implant Surfaces-An In Vitro Study

Objectives: Photochemical systems are frequently recommended as an adjuvant treatment option in peri-implantitis therapy. The aim of the present study was to evaluate the efficacy of these treatment options, as well as a novel curcumin-based option, in a biofilm model on implants. Methods: Eighty dental implants were inoculated with an artificial biofilm of periodontal pathogens and placed in peri-implant pocket models. The following groups were analyzed: I, photodynamic therapy (PDT); II, PDT dye; III, curcumin/DMSO + laser; IV, curcumin/DMSO only; V, dimethyl sulfoxide (DMSO) only; VI, photothermal therapy (PTT); VII, PTT dye; VIII, control. After treatment, remaining bacterial loads were assessed microbiologically using quantitative real-time polymerase chain reaction analysis. Results: The PDT, PTT, and DMSO treatment methods were associated with statistically significant (p < 0.05) improvements in germ reduction in comparison with the other methods and the untreated control group. The mean percentage reductions were as follows: I (PDT) 93.9%, II (PDT dye) 62.9%, III (curcumin/DMSO + laser) 74.8%, IV (curcumin/DMSO only) 67.9%, V (DMSO) 89.4%, VI (PTT) 86.8%, and VII (PTT dye) 66.3%. Conclusions: The commercially available PDT and PTT adjuvant treatment systems were associated with the largest statistically significant reduction in periopathogenic bacteria on implant surfaces. However, activation with laser light at a suitable wavelength is necessary to achieve the bactericidal effects. The use of curcumin as a photosensitizer for 445 nm laser irradiation did not lead to any improvement in antibacterial efficacy in comparison with rinsing with DMSO solution alone.

Antimicrobial activity of laser assisted endodontic therapy in disinfecting root canals

Light Amplified Stimulated Emission of Radiation (LASER) is nowadays widely studied regarding their use in endodontics and restorative dentistry. Therefore, it is of interest to evaluate the antibacterial activity of three types of LASERs namely CO2 LASER.Er, Cr:YSGG LASER and Diode LASER in disinfection of root canals. 70 patients (105 single rooted teeth) were included in the study. There was application of 2% Sodium Hypochlorite (NaOCl), 2780 nm Er,Cr:YSGG LASER, 900 nm Diode LASER and CO2 LASER. Microbial samples were collected from root canals both before and after the interventions through paper points. These parameters were evaluated in microbiology laboratory to obtain Log10 Colony Forming Units (CFUs). There was significant reduction in CFUs of microorganisms inside root canal in all three LASERs evaluated and NaOCl. The reduction in CFUs in LASERs was comparable to NaOCl. Then secondly we applied each LASER in combination with NaOCl. It was observed that reduction in CFU was greater when combination of LASER with NaOCl was applied as compared when applied alone. It can be inferred that LASER when applied with NaOCl can have significant role in disinfection of root canals.

Evaluation of Fracture Resistance of Reattached Tooth Fragments Restored Using Fiber-reinforced Composites: A Systematic Review

AIM AND BACKGROUND

This systematic review examined the current literature to evaluate the fracture resistance of the tooth fragments reattached using fiber-reinforced composites (FRC).

MATERIALS AND METHODS

An electronic search was performed on Scopus, PubMed, and Web of Science databases according to specific inclusion and exclusion criteria to identify relevant articles to be included until January 2023. Articles with full text available in the English language for randomized control studies, observational studies, retrospective studies, and in vitro studies conducted on permanent human teeth were selected. The risk of bias was assessed in all studies using the OHAT tool.

RESULTS

Out of 16 search results, seven in vitro studies with a total of 415 samples were included in the review. Three studies reported that reinforcement using rigid FRC posts improves fracture resistance of reattached anterior teeth, three studies reported that reinforcement using flexible fiber bundles enhances the fracture strength of reattached posterior teeth and one study reported that the use of flexible polyethylene fibers improves fracture resistance in molars with reattached cusps.

CONCLUSION

Within the limitations of the studies included in the review, there is low-quality evidence that reinforcement of reattached fragments using FRC posts or fibers improves fracture resistance.

CLINICAL SIGNIFICANCE

The reattached fractured fragments may be susceptible to re-fracture. The use of FRC to reinforce the resin composite used for reattachment may enhance the bond strength and increase resistance to fracture. How to cite this article: Albar NHM. Evaluation of Fracture Resistance of Reattached Tooth Fragments Restored Using Fiber-reinforced Composites: A Systematic Review. J Contemp Dent Pract 2024;25(6):605-615.

Comparison of Antimicrobial Effects of 445 and 970 nm Diode Laser Irradiation with Photodynamic Therapy and Triple Antibiotic Paste on Enterococcus faecalis in the Root Canal: an In Vitro Study

Background and aim: Colonization of residual organisms in the root canal are major causes of root canal treatment failure. Therefore, the effective removal of organisms during root canal cleaning stages is of great importance. In this study, we aimed to investigate and compare the antimicrobial effects of several methods including high power laser irradiation, photodynamic therapy and triple antibiotic paste (TAP) on Enterococcus faecalis in the root canal. Materials and methods: For the present laboratory study, 80 anterior single canal teeth were randomly divided into seven experimental groups (970 nm diode laser irradiation, 445 nm diode laser irradiation, 660 nm photodynamic therapy with doxycycline as a photosensitizer, TAP, 970 nm diode laser combined with TAP, 445 nm diode laser combined with TAP and sodium hypochlorite groups), each containing 10 teeth, and two positive and negative control groups, each containing five teeth. Afterwards, an E. faecalis suspension was prepared and injected into the root canals of all groups (except the negative control group), and after using the desired lasers or drugs and incubating for the necessary time, the grown colonies were counted and significance level of less than 0.05 was considered. Results:Among seven experimental groups, in those that included triple antibiotic paste (TAP, 970 nm diode laser with TAP, and 445 nm diode laser with TAP groups), no bacteria grew, while the 970 nm and 445 nm diode laser groups had the highest bacterial growth. Statistically, all studied groups were effective, and the results showed a statistically significant difference between groups (P value < 0.05). Conclusion: The findings of the present study show that all of the above-mentioned methods were effective enough for bacterial reduction. Triple antibiotic paste was proved to achieve complete bacterial elimination. Photodynamic therapy with doxycycline as a photosensitizer was shown to provide significant results of bacterial reduction and diode laser irradiation at both wavelengths (970 nm and 445 nm) were also reported to have antibacterial effect, although slightly lower than the previous methods.

Comparison of Antimicrobial Effects of 445 and 970 nm Diode Laser Irradiation with Photodynamic Therapy and Triple Antibiotic Paste on Enterococcus faecalis in the Root Canal: an In Vitro Study

Background and aim: Colonization of residual organisms in the root canal are major causes of root canal treatment failure. Therefore, the effective removal of organisms during root canal cleaning stages is of great importance. In this study, we aimed to investigate and compare the antimicrobial effects of several methods including high power laser irradiation, photodynamic therapy and triple antibiotic paste (TAP) on Enterococcus faecalis in the root canal. Materials and methods: For the present laboratory study, 80 anterior single canal teeth were randomly divided into seven experimental groups (970 nm diode laser irradiation, 445 nm diode laser irradiation, 660 nm photodynamic therapy with doxycycline as a photosensitizer, TAP, 970 nm diode laser combined with TAP, 445 nm diode laser combined with TAP and sodium hypochlorite groups), each containing 10 teeth, and two positive and negative control groups, each containing five teeth. Afterwards, an E. faecalis suspension was prepared and injected into the root canals of all groups (except the negative control group), and after using the desired lasers or drugs and incubating for the necessary time, the grown colonies were counted and significance level of less than 0.05 was considered. Results:Among seven experimental groups, in those that included triple antibiotic paste (TAP, 970 nm diode laser with TAP, and 445 nm diode laser with TAP groups), no bacteria grew, while the 970 nm and 445 nm diode laser groups had the highest bacterial growth. Statistically, all studied groups were effective, and the results showed a statistically significant difference between groups (P value < 0.05). Conclusion: The findings of the present study show that all of the above-mentioned methods were effective enough for bacterial reduction. Triple antibiotic paste was proved to achieve complete bacterial elimination. Photodynamic therapy with doxycycline as a photosensitizer was shown to provide significant results of bacterial reduction and diode laser irradiation at both wavelengths (970 nm and 445 nm) were also reported to have antibacterial effect, although slightly lower than the previous methods.

The efficacy of 2780 nm Er,Cr;YSGG and 940 nm Diode Laser in root canal disinfection: A randomized clinical trial

OBJECTIVES

Effective disinfection of the root canals is the cornerstone of successful endodontic treatment. Diminishing the microbial load within the root canal system is crucial for healing in endodontically treated teeth. The aim of this study was to evaluate the effect of 2780 nm Er,Cr:YSGG and 940 nm diode lasers on the eradication of microorganisms from single-rooted teeth with asymptomatic apical periodontitis.

MATERIALS AND METHODS

Thirty participants conforming to the inclusion criteria were randomly divided into 3 groups according to the disinfection protocol used; Conventional group: 2.5% Sodium Hypochlorite (NaOCl) and 17% EDTA solution NaOCl/EDTA, Dual laser group: 2780 nm Erbium, chromium: yttrium scandium-gallium-garnet (Er,Cr:YSGG) laser and 940 nm diode laser Er,CrYSGG/Diode, and Combined group: 17% EDTA and 940 nm diode laser EDTA/Diode. Bacterial samples were collected before and after intervention. The collected data were statistically analyzed using Friedman's test and Kruskal-Wallis test (P ≤ 0.05).

RESULTS

The results of the study showed that both dual laser Er,CrYSGG/Diode and combined laser EDTA/Diode groups showed significantly less mean Log10 CFU/ml of aerobic and anaerobic bacterial counts than the conventional NaOCl/EDTA group.

CONCLUSIONS

In this study we evaluated in vivo the bactericidal efficacy of three disinfection protocols for endodontic treatment of single-rooted teeth with apical periodontitis. The results indicated that both dual laser Er,CrYSGG/Diode and combined laser EDTA/Diode groups provide superior bactericidal effect compared to the conventional NaOCl/EDTA group.

CLINICAL RELEVANCE

The integration of lasers into root canal disinfection protocols has demonstrated significant bacterial reduction which might promote healing and long-term success.

CLSM-Guided Imaging for Quantifying Endodontic Disinfection

Elimination of microbes in the root canal system is crucial for achieving long-term success in endodontic treatment. Further efforts in study design and standardization are needed in order to improve the validity and comparability of in vitro results on endodontic disinfection procedures, in turn improving clinical outcomes. This study optimizes two models at all steps: tooth selection, pretreatment, inoculation method (by growth or centrifugation), and confocal laser scanning microscopy (CLSM)-guided imaging of LIVE/DEAD-stained specimens. Individual anatomical conditions lead to substantial differences in penetration depth. Sclerosis grading (SCG), a classification system introduced in this study, provides information about the sclerosis status of the dentine and is helpful for careful, specific, and comparable tooth selection in in vitro studies. Sonically activated EDTA for the pretreatment of roots, inoculation of Enterococcus faecalis in an overflow model, 3-4 weeks of incubation, as well as polishing of dentine slices before staining, led to advances in the visualization of bacterial penetration and irrigation depths. In contrast, NaOCl pretreatment negatively affected performance reproducibility and should be avoided in any pretreatment. Nonsclerotized teeth (SCG0) can be used for microbial semilunar-shaped inoculation by centrifugation as a "quick-and-dirty" model for initial orientation. In conclusion, CLSM-guided imaging for quantifying endodontic infection/disinfection is a very powerful method after the fine-tuning of materials and methods.

Temporary Root Canal Obturation with a Calcium Hydroxide-Based Dressing: A Randomized Controlled Clinical Trial

Successful bacterial inactivation or elimination is essential for successful outcomes in endodontics. This study investigated the efficacy of a calcium hydroxide paste (Ca(OH)2) as a temporary medical dressing for 1 week after chemomechanical root canal treatment (CMRCT). Microbiological samples from 26 patients were collected after endodontic emergency treatment as follows: (1) removal of the provisional filling material; (2) CMRCT; (3) irrigation with sodium hypochlorite I (3%); (4) medicinal insertion of Ca(OH)2; and (5) irrigation with sodium hypochlorite II (3%). A microbiological examination was carried out after the specimens had been taken from the root canals via saline and sterile paper points. CMRCT resulted in a significant reduction in total bacterial load (TBL) in the root canal (p < 0.05). Additional irrigation (3) resulted in a further significant reduction in TBL (p < 0.05). In contrast, Ca(OH)2 medication did not prevent the bacterial load from returning to the previous level immediately after CMRCT, but did not increase above that level either (p < 0.05). However, the increase in TBL was significant (p < 0.05) in comparison with the disinfection groups (I/II). Administration of Ca(OH)2 for 1 week shows that in combination with an additional disinfection procedure, an increase in TBL must be expected, but not above the level of conditions after CMRCT.

The application of lasers in vital pulp therapy: a review of histological effects

Vital pulp therapy (VPT) is primarily intended to preserve the vitality of pulp tissues, which have been exposed for any reason. Various materials and techniques have been proposed to improve treatment outcomes, including the use of lasers. This study aimed to review the histological results of different dental lasers including low-level lasers, carbon dioxide (CO2), erbium-doped yttrium aluminum garnet laser (Er:YAG), neodymium-doped yttrium aluminum garnet (Nd:YAG), erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers, and diode lasers for VPT. This focused review included a comprehensive electronic search of Scopus, MEDLINE, Web of Science, and Google Scholar databases from 2000 to 2022 by two independent investigators. Different combinations of keywords were used, and reference mining of related papers was done. The review included studies related to histologic evaluation of laser-assisted vital pulp therapy that stated the laser parameters that were used. Articles with radiographic or clinical assessments or articles lacking necessary data were excluded. Non-English articles were excluded unless their abstract was in English and encompassed the necessary data. Most studies indicated the efficacy of lasers for reduction of inflammation, acceleration of healing, and increasing the thickness of dentinal bridge. According to the evidence, lasers used in combination with pulp capping agents are beneficial to enhance the success rate of VPT.

Clinical Efficacy of Treatment of Endodontic-Periodontal Lesions: A Systematic Scoping Review of Experimental Studies

BACKGROUND

In this review, we evaluated the clinical efficacy of interventions used for the treatment of endo-perio lesions (EPL).

METHODS

A systematic scoping review of clinical trials was developed.

RESULTS

Seven clinical trials were studied. In at least one study group of six of the seven evaluated trials, endodontic and periodontal treatments were performed simultaneously. All trials showed improvement in probing depth in the studied groups; nevertheless, the experimental groups of five studies demonstrated a statistically significant reduction in this parameter. An increase in clinical attachment level was also reported (p < 0.05). Most trials reported an increase in the filling of the bone defect following therapy (p < 0.05). Mechanical periodontal therapy implemented simultaneously with endodontic therapy demonstrated efficacy in the treatment of concurrent EPL without communication. Endodontic treatment and immediate periodontal surgery did not affect the result of the management of combined EPL with apical communication. The use of diode laser, the management of platelet-rich fibrin (PRF) and titanium-prepared PRF, and the implementation of bone grafts plus endodontic treatment with mineral-trioxide or gutta-percha seems to be an adequate strategy in patients with EPL.

CONCLUSIONS

The treatment of EPL using simultaneous endodontic and periodontal therapies seems to be an acceptable treatment alternative.

Cytotoxicity and Efficacy in Debris and Smear Layer Removal of HOCl-Based Irrigating Solution: An In Vitro Study

In the present study we evaluated the cytotoxicity of super-oxidized water on human gingival fibroblasts and its efficacy in debris and smear layer removal from root canal walls. Cultured gingival fibroblasts were exposed to super-oxidized water (Sterilox), which was diluted in Iscove’s modified Dulbecco’s medium (IMDM) at 30%, 40%, 50%, 60% and 70% concentrations. The control group was maintained in IMDM. The cell viability was evaluated by means of an MTT assay after incubation periods of 1 h, 2 h, 24 h and 48 h. Pathological cellular changes were also observed under fluorescence and phase contrast microscopes. The efficacy in debris and smear layer removal was evaluated in comparison to the conventional application of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA). Forty maxillary premolars were randomly divided into two equal groups (n = 20) and shaped with ProTaper NEXT rotary instruments using Sterilox or NaOCl/EDTA for irrigation. Afterwards, roots were split longitudinally and examined under a scanning electron microscope. The results revealed that super-oxidized water and sterile distilled water have acceptable biological properties for endodontic applications at concentrations up to 50% (p > 0.05). Moreover, super-oxidized water is equally effective in debris and smear layer removal as compared to NaOCl/EDTA (p > 0.05).