Efficacy of adjunctive Er,Cr:YSGG laser application to scaling and root planing in periodontal maintenance patients with residual periodontal pockets Abstract Purpose The aim of this study was to evaluate the efficacy of using Er,Cr:YSGG laser in an adjunct to scaling and root planing (SRP + Er,Cr:YSGG) in periodontal maintenance patients with residual periodontal pockets. Materials and methods This study is a double-blind randomized controlled clinical trial and a split-mouth design. Fifteen periodontal maintenance patients with two single-rooted teeth with probing depth (PD) ≥ 5 mm in two different quadrants were randomly assigned to scaling and root planing (SRP) as a control group or SRP + Er,Cr:YSGG as test group. Plaque index (PI), bleeding on probing (BOP), PD, relative probing attachment level (RPAL), and relative gingival recession (RGR) were evaluated at baseline, 3 months and 6 months after treatment by one calibrated examiner. Results At 6 months after treatment, PDs were statistically significantly reduced in both SRP (0.9 ± 0.6 mm) and SRP + Er,Cr:YSGG (1.1 ± 0.7 mm) compared with pretreatment PD (p < 0.05). Only SRP + Er,Cr:YSGG demonstrated statistically significant probing attachment level (PAL) gained at 6 months after treatment (0.8 ± 0.6 mm; p < 0.05). Gingival recession (GR) statistically significantly increased in SRP + Er,Cr:YSGG 3 months after the treatment (0.5 ± 0.5 mm; p < 0.05). Nevertheless, there were no statistically significant differences between the 2 treatment modalities regarding PD reduction, PAL gain, or GR at 6 months after treatment. Conclusions Only SRP + Er,Cr:YSGG demonstrated statistically significant PAL gained at 6 months after treatment (0.8 ± 0.6 mm; p < 0.05); however, there were no statistically significant differences between the 2 treatment modalities regarding PD reduction, PAL gain, or GR at 6 months after treatment in maintenance patients with residual periodontal pockets.

In vitro evaluation of the push-out bond strength of the epoxy resin-based root canal sealer to root dentin irradiated with double-wavelength lasers Abstract Purpose The influence of dual-wavelength lasers Er,Cr:YSGG 2780 nm and diode 940 nm on bond strength of the epoxy resin-based sealer (AH Plus) to the root dentin was evaluated. Methods Thirty-three extracted human mandibular and maxillary straight and single-rooted teeth were sectioned at the cementoenamel junction perpendicular to the long axis. All the teeth were endodontically prepared and cut with thin disc 1.1 mm thickness transversally to the long axis. The teeth were randomly divided into three groups (n = 40). In group 1, 1 ml of NaOCl (5.25%) was used between every drill exchange for irradiating the canals. Group 2 was irradiated with EDTA (17%) and NaOCl in order to remove the smear layer from the canals. In group 3, the canals irradiated with 2780 nm Er,Cr:YSGG laser using radial firing tips and 940 nm diode laser. One root from every group was selected for scanning electron microscopy (SEM) analysis. Statistical analysis was performed using the Shapiro–Wilk test and one-way ANOVA test. Results Statistically significant differences were observed in group 2 (EDTA Plus NaOCl) compared with the two other groups (p < 0.001). There were no significant differences between the laser and control group (p = 0.987). The mode of failure in all groups was the cohesion failure indicating the failure within the sealer. SEM examination confirmed the presence of a thick smear layer in group 1 and open dentinal orifices in groups 2 and 3. Conclusion In spite of removing the smear layer, the dual-wavelength laser has no effect on the push-out bond strength of AH Plus sealer.

Hyperspectral imaging system associated with novel subtracting image processing algorithm for dental caries early detection Abstract Objective Early detection of caries is vital for demineralization reverse offering a less pain, as well as accurate and precise caries removal. Materials and Methods In this study, the difference in optical properties of normal tissue and human caries lesion has been used for early diagnosis, using laser induced fluorescence spectroscopy. The human tooth sample was illuminated with visible band sources (488, 514 and 633 nm) with power 5 mW. The reflected and emitted light of tested sample was collected using hyperspectral camera in an attempt to generate multispectral images (cubic image). The variation of reflected and emitted power as function in wavelength was employed to generate characteristic spectrum of each tooth tissue. Human teeth caries tissue lesion releases its excess power by emitting fluorescence light producing chemical footprint signature; this signature is dependent on the elemental composition of tooth elements and caries state. Results This non-invasive, non-contact and non-ionizing imaging system with associated novel pattern recognition algorithm was employed to diagnose and classify dental (enamel and dentin), caries, and white spot lesion. It was reported that the perceived fluorescence emission is function of the illuminating wavelength. While enamel and dentin caries were distinguished and characterized at 633 nm illuminating wavelength; white spot lesion cannot be detected. The enamel caries, dentin caries, and white spot lesion were contoured and recognized at 488 nm and 514 nm wavelengths. Therefore full recognition was achieved through generated cubic image after sample irradiation at 488 nm and 514 nm. Conclusions This non-invasive, non-contact, and non-ionizing imaging technique with customized image processing algorithm offered high sensitivity, high resolution, and early caries detection with optimum performance at 514 nm.

Photobiomodulation therapy in the treatment of periodontal disease: a literature review Abstract Objectives Many studies in the literature address the effect of photobiomodulation therapy in the management of pathologies related to periodontal tissue. Due to the lack of standardized information and the absence of a consensus, this review presents the recent evidence on the effect of photobiomodulation (PBM) on proliferation of fibroblast cells and osteoblast cells in periodontal tissues. Materials and methods The literature and original research articles were used to investigate the effect of photobiomodulation therapy in periodontal diseases. Online MEDLINE/PubMed and Google scholar were used. Access dates were between 2010 and 2017. The research was confined to English-language literature. The literature search retrieved references on proliferation of fibroblast cells and osteoblast cells. Each topic is individually addressed in this review. Results In total, 13 14 relevant photobiomodulation articles were included in the review, comprising work completed on a variety of cell types and places. Although results consistently demonstrated the potential of laser irradiation to affect cellular proliferation in a wavelength- and dosage-dependent manner, the relevance of other key irradiation parameters, such as irradiance, to such effects remained unclear. Conclusion The literature review showed several positive results of the PBM on proliferation of fibroblast cells and osteoblast cells in periodontal tissues.

The tensile strength of laser welding of an incision in the keratinized oral mucosa of rabbits in vivo Abstract Introduction In this study, coagulation of the blood at the wound side is evoked using a 980-nm-wavelength diode laser. The laser is used to approximate incision wound edges to be compared with the healing of the sutured incision. Clinical observations, histological slides, and tensile strength measurement are performed to assess the quality of healing. Material and methods The study is conducted on 24 albino rabbits; an intraoral incision in the hard palate is done on both sides, right and left, for each rabbit. One side serves as a control group where the incision is sutured, while the other side’s incision is welded by a 980-nm-wavelength laser. The laser is operated in continuous wave mode (CW) 20 W/cm2 power density for 27 s exposure time. Results Clinically, there was some loss of tissue details (smooth feature) on the welded side in comparison with the conventionally treated side. Histopathologically, healing of the epithelial layer was perfect, while the submucosal layer showed loss of angiogenesis and loose connective tissue replacing the normal structure. The tensile strength measurement shows comparable results for the welded incision and the sutured incision; moreover, the immediate and first-day tensile strength of the welded incision shows superior results to the sutured incision. Recommendation Further studies are needed to monitor histologically the healing after laser welding and measure the development in the tensile strength to assess the validity of the 980-nm-wavelength laser beam as a tool in tissue welding. Conclusion Nine hundred eighty-nanometer-wavelength laser beam is a suitable tool for welding incisions in the oral cavity at areas subjected to stress, such as a socket after tooth extraction.

Photobiomodulatory effect delivered by low-level laser on dental pulp stem cell differentiation for osteogenic lineage Abstract Background Photobiomodulation (PBM) therapy has attracted major interest in the field of tissue engineering as it can enhance stem cell differentiation. It has been shown that PBM therapy can stimulate differentiation of cells in culture by exerting biomodulatory effect. Recent evidences show that PBM therapy can positively modulate dental pulp stem cell (DPSC) properties. Combination of PBM therapy with growth factors and biomaterials can possibly accelerate osteogenic differentiation of dental pulp stem cells. Aims To evaluate the biomodulatory effect of low-level laser dose on dental pulp stem cells in the presence of hydroxyapatite-based scaffold particle for osteogenic differentiation. Materials and methods DPSCs were harvested from human premolar teeth and expanded using mesenchymal stem cell medium. Characterization of DPSCs was done using fluorescence-activated cell sorting with CD105, CD44, CD34, and CD45 markers. Cultured DPSCs along with the N-acetylcysteine-labeled hydroxyapatite (NAC-HA) particles and osteogenic differentiation media were exposed to gallium-aluminum-arsenide (Ga-Al-As) diode laser at 810 nm. Cells were divided into 3 groups: L1 (single exposure), L2 (double exposure), and control (no exposure). Osteodifferentiation after PBM therapy was assessed using Alizarin red S staining, Alkaline phosphatase activity (ALP), and by osteopontin expression. Differences between groups at each time point were analyzed using the Mann–Whitney U test. A level of significance of 5% was adopted (p < 0.05). Results DPSCs grown on NAC-HA polymers show increased cell adhesion and proliferation. Double irradiated groups were consistent with increased calcium (71%) and alkaline phosphatase activity (75%) when compared with single-irradiated groups. mRNA expression of osteopontin was relatively increased in a significant (p < 0.001) manner in L2 when compared with L1 group. Alizarin red S and ALP positive staining confirmed the presence of calcium deposition in the test samples. The osteopontin expression of L2 (216.681) as compared with L1 (123.276) group prove the efficacy of double exposures over a single dose of PBM therapy. Conclusion The result envisages the enhanced osteogenic potential of PBM therapy on the differentiation of DPSCs in NAC-HA scaffolds. Double exposure of PBM therapy expresses better biomodulatory effect on DPSCs as compared with the single dose.

The 2780-nm Er,Cr:YSGG laser in endodontic treatment of teeth with iatrogenic root perforations: technique description and case series

Comparison of Er:YAG laser and acid etching methods prior to lingual retainer application in vitro Abstract Purpose The aim of this study is to compare the bond strength, fracture type, and the amount of microleakage related to lingual retainers bonded on enamel surface etched with either Erbium:Yttrium-Aluminum-Garnet (Er:YAG) laser or acid etching methods. Methods The enamel of extracted 132 upper incisor teeth was etched using either 37% phosphoric acid or Er:YAG laser (Fotona Light Walker H02-N 2940 nm, 120 mJ, 10 Hz, 1.2 W in MSP mode). Teeth were embedded in acrylic as two teeth in each sample with 135° angulation and retainer wires were bonded on the lingual surface of the samples. Two-year aging protocol was applied using a chewing simulator and a thermal cycler. Shear bond strength (SBS), adhesive remnant index (ARI), and microleakage were measured. Results SBS and microleakage data were analyzed using the Mann–Whitney U test and ARI scores using the Pearson chi-square test. The SBS was found significantly higher in the acid-etched group. There was no statistically significant difference in the total microleakage means between groups. There was no statistically significant difference in the microleakage between the enamel-adhesive and adhesive-retainer interfaces for the mesial and distal sides. Higher microleakage values were measured between the enamel and the adhesive surfaces compared to adhesive-retainer interface for both groups. Conclusion Within the limitations of our study, acid etching promises better bond strength for lingual retainers compared to Er:YAG laser etching. There was no significant difference between the groups in terms of microleakage.

Erbium YAG laser and diode laser applications for the second phase of implant surgery: a comparison of clinical outcomes Abstract Purpose This study assessed the clinic outcomes of erbium: yttrium/aluminum/garnet (Er:YAG) laser and diode laser use in second phase of implant surgery. Methods Fifty implants scheduled for stage II implant surgery were randomly assigned to 4 groups. In the first group (G1), Lite-touch Er:YAG laser was selected, and a vacuum-formed template was used for each site to indicate surgical entrance. For the second group (G2), Lite-touch Er:YAG laser was used and the surgery was performed in a free-hand way. The third group (G3) adopted free-hand surgery while diode laser was used. In the last group (G4), LightWalker Er:YAG laser was applied by free hand. The surgeon was allowed to look at cross-sectional images and 3D reconstruction in the computer to obtain implant position in G2, G3, and G4. The time of operation, healing time, and accuracy of operation were assessed. Results G1 and G4 took the shortest time in surgery than that of the other two groups (P < 0.05). The largest deviation in uncovered implant was shown in G4 (P < 0.05). No accuracy difference was found among G1, G2, and G3 (P > 0.05). The healing time of Lite-touch Er:YAG laser with or without surgical guide was the shortest when compared with the other two groups (P < 0.05). G3 had the longest healing time among the 4 treatment modalities (P < 0.05). Conclusion When applied in the implant uncover surgery, Er:YAG laser presents shorter healing time than diode laser. Contact laser operation provides more accuracy than noncontact operation.

Comparison between the effect of low-level laser therapy and corticotomy-facilitated orthodontics on RANKL release during orthodontic tooth movement: a randomized controlled trial Abstract Objective Bone resorption is the cornerstone in bone remodeling affecting the rate of orthodontic tooth movement. RANKL has a direct effect on osteoclastogenesis. The aim of this study is to evaluate and compare the effect of low-level laser therapy (LLLT) and corticotomy-facilitated orthodontics (CFO) on RANKL release during orthodontic tooth movement. Materials and methods Twenty patients requiring orthodontic therapeutic extraction of the maxillary first premolar were randomly selected. A split-mouth study design was performed where corticotomy-facilitated orthodontics was randomly assigned to one side at the canine region (CG) before retraction, Laser group (LG) was assigned to the contralateral side using 940 nm diode laser irradiations (100 mW, 2.5 J, 3.9 J/cm2) at days 1, 3, 8, and 15. Canine retraction was done using nickel-titanium closed-coil spring applying a force of 150 g per side. Gingival crevicular fluid (GCF) samples were collected from distal surface of the canines on both sides, 1 day before the intervention treatment (T0), day 3 after the intervention (T1), and day 15 (T2). RANKL concentration levels were assessed using enzyme-linked immunosorbent assay. Results There was statistically significant increase in RANKL concentration levels in both groups (CG and LG) from T0 to T1, there was no statistically significant difference in concentration level from T1 o T2, but there was a statistically significant difference in RANKL concentration levels between T0 and T2 in both groups. CG and LG showed no statistically significant difference in RANKL concentration levels between them in T1 and T2. Conclusions Low-level laser therapy and corticotomy-facilitated orthodontics can increase the RANKL release during orthodontic tooth movement which directly affects bone remodeling and the rate of orthodontic tooth movement.