Effect of Er: YAG or Nd:YAG Laser Exposure on Fluorosed and Non-Fluorosed Root Surfaces: An <i>In vitro</i> Study

Abstract

Background and aims:Fluorosis affects tooth mineralization. The therapeutic benefit provided by lasers on fluorosed and non fluorosed cementum requires studying and comparing. The aim of this study was to evaluate and compare the root surface changes following Er:YAG or Nd:YAG laser irradiation on periodontally healthy fluorosed versus non-fluorosed teeth by scanning electron microscopy (SEM). Materials and methods: A total of 76 periodontally healthy fluorosed (FH) and non-fluorosed (NFH) teeth specimens were included in this study. In one group, the experimental root specimens were irradiated using Er:YAG or with Nd:YAG laser in the other. A SEM evaluation was performed to assess the laser induced ultra structural changes in the root surface followed by statistical analysis using Fisher's exact test. Results: It was observed that both FH and NFH groups were similarly affected by Nd:YAG or Er:YAG laser. However, the former caused more surface changes than the latter on melting of surface (p=0.12 for FH and p=0.08 for NFH), and Er:YAG laser caused more smear layer formation (p=0.51 for FH and p=0.16 for NFH). Conclusion: Results suggest that undesirable morphological changes were observed almost similarly in FH and NFH groups using Er:YAG or Nd:YAG laser. Hence further in-vitro studies at lower energy settings followed by clinical trials are required in this aspect.

Effect of chlorhexidine application or Nd:YAG laser irradiation on long-term bond strength of a self-etching adhesive system to dentin

“…It has been reported that Nd:YAG laser irradiation promotes the overheating of dental structures followed by their recrystallization [22]. This process results in an acid-resistant, melted dentin surface [23,24] that can impair resin bond infiltration [22]. This can explain the fractures in the laser-irradiated group, which were predominantly of the adhesive type (Fig.…”

“…Similar results were obtained by Lise et al [16], who observed that the microtensile bond strength of adhesive materials to Nd:YAG-irradiated dentin was lower than to non-irradiated dentin. It has been reported that Nd:YAG laser irradiation promotes the overheating of dental structures followed by their recrystallization [22]. This process results in an acid-resistant, melted dentin surface [23,24] that can impair resin bond infiltration [22].…”

Assessment of the Periodontal Cementum Ablation Depth during Root Planing by an Er:YAG Laser at Different Energy Densities: An Ex Vivo Study

“…Other type of lasers such as the CO 2 , Low Level Laser (LLL) have been used in photo-biomodulation therapy to decrease gingival inflammation and enhance the healing process by reducing the essential mediator in the acute inflammatory response known as prostaglandins [15,16]. Moreover, CO 2 lasers have been reported to cause melting of root surfaces similar to Nd:YAG lasers [17,18]. Although the anti-bacterial and ablative effects of laser wavelengths have been discussed widely in the literature [19][20][21], limited laser wavelengths are able to conduct efficient cementum cleaning [22] and are able to create the lowest amount of surface roughness when low levels of energy have been used [23].…”

“…Although the anti-bacterial and ablative effects of laser wavelengths have been discussed widely in the literature [19][20][21], limited laser wavelengths are able to conduct efficient cementum cleaning [22] and are able to create the lowest amount of surface roughness when low levels of energy have been used [23]. It is also important to mention that when Er:YAG lasers are used in SRP, neither cracks, microfractures, nor thermal side effects were observed on root surfaces [18].…”