Effects of laser-aided circumferential supracrestal fiberotomy on root surfaces

Chemical and morphological analysis of dentin irradiated by different high-power lasers: a systematic review

PURPOSE

This systematic review provides an overview of the main chemical and morphological alterations generated on dentin by different high-power lasers' irradiation.

METHODS

The review was registered in PROSPERO (CRD42023394164) and PRISMA guidelines were followed. The search strategy was conducted on MEDLINE (PubMed), Embase (Elsevier), and Web of Science (Clarivate) databases. The eligibility criteria were established according to the PICOS strategy, focusing on in vitro and ex vivo studies that assessed the chemical and morphological changes in dentin using five high-power lasers: Nd:YAG (1064 nm), Er:YAG (2940 nm), Er, Cr:YSGG (2780 nm), diode (980 nm), and CO2 (10,600 nm). Publication range was from 2010 to 2022. Data was summarized in tables and risk of bias was assessed by QUIN tool.

RESULTS

The search resulted in 2255 matches and 57 studies composed the sample. The methods most used to assess the outcomes were scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and Raman. The studies presented "medium" and "low" risk of bias. The laser prevalently identified was the Er:YAG laser, associated with dentin ablation, absence of smear layer, and exposed tubules. The Nd:YAG laser generated vitreous surface and thermal damage, such as carbonization and cracks. The other lasers caused an irregular surface and no adverse thermal effects. Regarding the chemical structure, only the Er,Cr:YSGG laser caused collagen matrix reduction. The effects found were more intense with higher dosimetry.

CONCLUSION

Evidence available indicates that the irradiation of dentin with high-power lasers are related to morphological outcomes favorable to adhesive restorative procedures, with minimal changes in collagen matrix and mineral content. However, those observations should be carried carefully by clinicians and more clinical trials regarding the association of high-power laser irradiation and restorative procedure longevity are needed.

Comparing Circumferential Supracrestal Fiberotomy with Surgical Scalpel Versus Photobiomodulation in Orthodontic Relapse Reduction: A Clinical Trial

Objective: This investigation aimed to compare the efficacy of circumferential supracrestal fiberotomy (CSF) with surgical scalpel, laser CSF, and photobiomodulation for reduction of relapse after orthodontic tooth rotation. Background: Relapse is the tendency of teeth to move back to their preoperative position after removal of orthodontic appliances. Materials and methods: This randomized controlled clinical trial was conducted on 90 rotated teeth at the final stages of fixed orthodontic treatment. The teeth were randomly divided into six groups (n = 15) of (1) control (no intervention), (2) photobiomodulation alone (wavelength of 940 nm, 0.2 W, and 4 J/cm2), (3) conventional CSF, (4) laser CSF (wavelength of 940 nm, 1.5 W, and 4 J/cm2, and power density of 160 mW/cm2), (5) conventional CSF plus photobiomodulation, and (6) laser CSF plus photobiomodulation. Measurements were made on clinical photographs and dental casts using the AutoCAD software. Level of pain of patients was measured within the first 24 h after fiberotomy using a visual analog scale. Data were analyzed by ANOVA and Kruskal-Wallis test (α = 0.05). Results: The magnitude (p = 0.014) and percentage (p = 0.035) of relapse were significantly different among the six groups, and they were the highest in the control group followed by photobiomodulation alone, laser CSF, conventional CSF, conventional CSF plus photobiomodulation, and finally, laser CSF plus photobiomodulation. Moreover, photobiomodulation plus laser CSF and photobiomodulation plus conventional CSF had significantly different results from the other groups. The six groups had no significant difference in sulcus depth changes, gingival recession (difference in primary and secondary crown height), or pain score (p > 0.05). Conclusions: This study suggests that utilizing photobiomodulation combined with laser CSF or conventional CSF can be effective in reducing relapse. However, further clinical trials are required to support this idea. Iranian Registry of Clinical Trials (IRCT20210621051653N1).

Comparison of conventional and laser-aided fiberotomy in relapse tendency of rotated tooth: A randomized controlled clinical trial

INTRODUCTION

The aim of the present study was to compare the tendency of mandibular incisor rotation relapse after conventional circumferential supracrestal fiberotomy (CSF) with Er,Cr:YSGG laser-aided CSF.

METHODS

In this three-arm parallel study, the patients with one lower incisor rotation greater than 30 degrees before treatment were selected. The patients were randomly assigned to three groups in a 1:1:1 ratio. Rotational relapse tendency was measured on a digitized model one month after arch wire removal. Probing depth, clinical crown height and pain levels were also measured.

RESULTS

A total of 46 patients were recruited. Relapse tendency in conventional CSF and laser-aided CSF groups were 5.09±1.59° and 4.87±2.08°, respectively, and significantly lower than 11.28±2.93° in the control group (P<0.001). Relapse tendency was not different between the conventional CSF and laser CSF groups. Probing depth, clinical crown height, and experienced pain levels exhibited negligible differences.

CONCLUSIONS

Er,Cr:YSGG laser-aided CSF in one month was as effective in reducing rotational relapse tendency of mandibular incisor teeth as conventional CSF.

Application of laser in oral surgery

In this review collected from the literature on usage of laser in oral minor surgery based on a Medline search in the time period between the years: 2008 and 2013, the most current evidence on laser-assisted oral minor surgery is going to be surveyed.

Effect of 980-nm diode laser-aided circumferential supracrestal fiberotomy on fluorosed root surfaces

OBJECTIVE

To evaluate and compare the root surface morphological changes after 980-nm diode laser-aided circumferential supracrestal fiberotomy (CSF) on fluorosed and non-fluorosed teeth.

MATERIALS AND METHODS

The sample comprised 27 orthodontic patients (14 males and 13 females; mean age  =  17.3 years) with and without fluorosis, from whom 40 fluorosed and 40 non-fluorosed premolar teeth were extracted for orthodontic reasons. Conventional (control group) and laser-aided (experimental group) CSF was performed on fluorosed and non-fluorosed teeth indicated for orthodontic extraction, using a scalpel and a 980-nm diode laser at 2.5 W power, respectively. Subsequently, teeth were extracted, sectioned, and examined by scanning electron microscope to assess the ultrastructural changes.

RESULTS

There were differences in surface morphology among fluorosed and non-fluorosed roots in the control group. The root specimens of both fluorosed and non-fluorosed teeth irradiated by diode laser exhibited no evidence of smear layer, laser-induced pitting or cavitation, linear cuts/markings, carbonization of surface, and heat-induced surface cracking. However, a glazed or slightly melted appearance was observed in root specimens of fluorosed teeth after diode laser irradiation.

CONCLUSIONS

These findings suggest that the diode laser-aided CSF procedure is free from thermal hazard on non-fluorosed root surfaces but may provoke some thermal changes on fluorosed root surfaces.