ABSTRACT
Fissure sealant application is an efficient method for dental caries prevention. Self-etch fissure sealants (SE-FS) eliminate the separate etching step for bonding. The present study investigated the micro-shear bond strength (µSBS) of a SE-FS (Prevent seal®, Itena©, Paris, France) to enamel pretreated with different methods including Er,Cr:YSGG laser, under noncontaminated and saliva-contaminated conditions. Sixty human premolars were sectioned into halves and randomly assigned into two groups of saliva-contaminated and noncontaminated. Each group was further divided into six subgroups (N = 10) of different enamel pretreatment methods: (Laser+SE-FS), (Acid-etch+SE-FS), (Laser+Acid-etch+SE-FS), (Mechanical preparation+SE-FS), (SE-FS), and (Acid-etch+Bonding+Conventional fissure sealant) as positive control. The µSBS of the sealant material to enamel was measured in all subgroups. The two-way ANOVA and Tukey tests were applied at P < 0.05. Saliva contamination had a significant effect on µSBS (P < 0.001), while pretreatment with laser or acid etching did not significantly affect the µSBS (P = 0.251). The µSBS of SE-FS to untreated enamel surface was significantly lower than the positive control (P = 0.035). The µSBS value in the subgroup receiving laser+etching+SE-FS was significantly higher than the remaining five subgroups (P < 0.001). Other pairwise comparisons were not statistically significant (P > 0.05). Acid-etch and Er,Cr:YSGG laser exert a synergic effect on µSBS of Prevent Seal®, irrespective of saliva contamination.
Subject(s)
Dental Caries , Lasers, Solid-State , Humans , Pit and Fissure Sealants , Acid Etching, Dental/methods , Dental EnamelABSTRACT
OBJECTIVE: Low-level laser therapy is a method for osteogenesis since it stimulates cell proliferation, vascularization and osteoblastic activity. Various protocols applying low-level laser with different outcomes exist. The aim of the present study was to review the result of different methods on bone formation in critical-size defects of in vivo studies. DESIGN: According to PRISMA statement, electronic search of PubMed, google scholar, Scopus and Web of Science and a hand search limited to in vivo English language studies until December 2019. Studies used low-level laser therapy in bone regeneration of critical-size defects met the inclusion criteria and which used high power lasers or a defect size smaller than 5 mm, were excluded. RESULTS: Finally, 18 studies were included. Fourteen studies utilized low-level laser with a wavelength ranging from 606 to 980 nm and 53 % of studies applied low-level laser in a single session. Ten studies utilized continuous wave mode of laser. Highest and lowest values of power density were 1.5 W/cm2 and 0.1 W/cm2 in order. Eleven studies evaluated low-lever laser therapy on defects of 5 mm in calvaria. Meta-analysis showed the positive effect of low-level laser therapy on osteogenesis after 30 days compared to control group and no significant difference after 60 days. CONCLUSIONS: New bone formation can be increased in early stage by applying low-level laser therapy through stimulating osteoblasts and fibroblasts' proliferation. This effect would be more remarkable by combining with bone substitutes. Hence, for each case, protocol selection should be performed according defect's properties, attentively.
Subject(s)
Bone Regeneration , Low-Level Light Therapy , Osteogenesis , Skull/radiation effects , Animals , Skull/pathologyABSTRACT
Introduction: The efficacy of erbium-doped yttrium aluminum garnet (Er:YAG) laser for root debridement in comparison with curettes has been the subject of many recent investigations. Considering the possibility of chemical and ultra-structural changes in root surfaces following laser irradiation, this study sought to assess the effects of scaling and root planing (SRP) with curettes and Er:YAG laser on chemical properties and ultrastructure of root surfaces using spectroscopy and scanning electron microscopy (SEM). Methods: In this in vitro experimental study, extracted sound human single-rooted teeth (n = 50) were randomly scaled using manual curettes alone or in conjunction with Er:YAG laser at 100 and 150 mJ/pulse output energies. The weight percentages of carbon, oxygen, phosphorous and calcium remaining on the root surfaces were calculated using spectroscopy and the surface morphology of specimens was assessed under SEM. Data were analyzed using one-way analysis of variance (ANOVA). Results: No significant differences (P > 0.05) were noted in the mean carbon, oxygen, phosphorous and calcium weight percentages on root surfaces following SRP using manual curettes with and without laser irradiation at both output energies. Laser irradiation after SRP with curettes yielded rougher surfaces compared to the use of curettes alone. Conclusion: Although laser irradiation yielded rougher surfaces, root surfaces were not significantly different in terms of chemical composition following SRP using manual curettes with and without Er:YAG laser irradiation. Er:YAG laser can be safely used as an adjunct to curettes for SRP.
ABSTRACT
INTRODUCTION: The efficiency of routine scaling and root planning is negatively influenced by the tooth anatomy and residual bacteria all possibly affecting the treatment outcomes in future. The present study compared the microbiologic effectiveness of the photodynamic therapy (PDT) as an adjunctive treatment modality for nonsurgical treatment in chronic periodontitis. METHODS: In this randomized controlled clinical trial, 18 chronic periodontitis patients were selected. Four quadrants were randomly treated by scaling and root planning (SRP), diode laser (810n m wavelength, 1.5 W and 320 µm fiber, contact and sweeping technique), SRP + PDT (with diode laser 808 nm, 0.5 W) and laser + SRP (with diode laser 808 nm, 1 W) in each patient. Presence of periodontal pathogen species in the treated areas were measured before the treatment, at 1 and 3 months afterwards. The identification and reproduction of the specific genes of pathogen bacteria were done by means of polymerase chain reaction (PCR) technique. Presence of oral pathogen bacteria in the treatment groups were analyzed by chi-square test. A semi quantitative analysis was used to measure the intensity of white light in each band. This was calculated by number of pixels in each band. RESULTS: In the qualitative analysis, Fusobacterium nucleatum (Fn) and Treponema denticola (Td) species were killed after 1 month in all treatment modalities. PDT had more effects to decrease Prevotella intermedia (Pi) species than SRP while Tannerella forsythensis count (Tf) species increased in all treatments. Furthermore, Actinobacillus actinomycetemcomitans (Aa) species decreased in all treatments and Porphyromonas gingivalis (P.g) species increased in all treatments after 1 and 3 months. CONCLUSION: It can be concluded that PDT was more effective as an adjunctive treatment to SRP than SRP alone; however, no distinct differences were found between both treatment modalities regarding reduction of certain pathogen bacteria.
