Using 445 nm and 970 nm Lasers on Dental Implants-An In Vitro Study on Change in Temperature and Surface Alterations

The aim of this study was to evaluate the safety of using a 445 nm laser on dental implants by comparing it with a laser with 970 nm wavelength. Two models, a pig mandible and glass ionomer cement, were used to evaluate the temperature increase in dental implants during laser irradiation with both wavelengths. Temperature was measured every second at four different places on the dental implants. Different power settings, effects of water cooling, distance of the laser fibre to the dental implant and continuous comparison to a pulsed laser beam were tested. Surface alterations on titanium discs after laser irradiation for 4 min at 2.0 W, were analysed in a scanning electron microscope (SEM). The maximum temperature and time to reach each of the thresholds were comparable between the 445 nm and 970 nm lasers. Neither the 445 nm nor the 970 nm wavelength showed any signs of surface alterations on the titanium discs. Using a 445 nm laser on dental implants is as safe as using a 970 nm laser, in terms of temperature increase and surface alterations. Applying a generous amount of cooling water and irradiating in short intervals is important when using lasers on dental implants.

Effect of Nd:YAG laser-assisted non-surgical periodontal therapy on clinical periodontal and serum biomarkers in patients with and without coronary artery disease: A short-term pilot study

BACKGROUND/OBJECTIVE

We hypothesized that nonsurgical-periodontal-therapy (NSPT) with adjunct Nd:YAG laser therapy is more effective in reducing periodontal inflammatory parameters (plaque index [PI], bleeding-on-probing [BOP], and probing-pocket-depth [PPD]) and serum interleukin-1beta (IL-1β) and matrix metalloproteinase-9 (MMP-9) levels in patients with and without coronary artery disease (CAD) than NSPT alone. The aim of this short-term pilot study was to assess the effect of NSPT + Nd:YAG laser therapy on periodontal parameters and serum IL-1β and MMP-9 levels in patients with and without CAD.

STUDY DESIGN

A prospective randomized clinical study was conducted on 87 patients who were divided into two groups: Group-1: 44 patients with CAD and periodontal disease (PD) and Group-2: 43 patients with PD alone. Treatment-wise, these individuals were randomly divided into two subgroups: (i) NSPT alone and (ii) NSPT + Nd:YAG laser therapy. Demographic information was collected using a self-completed questionnaire. Periodontal parameters (PI, BOP, and PPD) and serum IL-1β and MMP-9 levels were measured at baseline and after 3 months of treatment. P-values <0.05 were considered statistically significant.

RESULTS

At 3 months follow-up, PI (P < 0.01), BOP (P < 0.01), PPD ≥ 4 mm (P < 0.01), and serum IL-1β (P < 0.01) and MMP-9 (P < 0.01) levels were significantly higher in patients treated with NSPT alone than those treated with NSPT + Nd:YAG laser therapy. Among patients that underwent NSPT + laser therapy in both groups, periodontal parameters and serum IL-1β, and MMP-9 levels were comparable at 3-months follow-up.

CONCLUSION

NSPT + Nd:YAG laser therapy may be more effective in reducing periodontal inflammation and serum IL-1β and MMP-9 levels in patients with and without CAD than NSPT alone. Lasers Surg. Med. 48:929-935, 2016. © 2016 Wiley Periodicals, Inc.

Efficacy of photodynamic therapy in the management of oral premalignant lesions. A systematic review

OBJECTIVE

The aim was to systematically review the efficacy of photodynamic therapy (PDT) in the management of oral premalignant lesions.

METHODS

The addressed focused question was "Is PDT effective in the management of oral premalignant lesions?" PubMed/Medline, Google-Scholar, EMBASE and ISI Web of Knowledge databases were searched from 1984 till June 2014 using different combinations of the following keywords: photodynamic therapy; oral premalignant lesions; leukoplakia; erythroplakia; erythro-leukoplakia; verrucous hyperplasia; and submucous fibrosis. Review articles, experimental studies, case-reports, commentaries, letters to the Editor, unpublished articles and articles published in languages other than English were not sought. The pattern of the present study was customized to mainly summarize the relevant information.

RESULTS

Thirteen studies were included. In these studies, the number of patients ranged between 5 patients and 147 individuals with mean ages ranging between 51 years and 62.2 years. Oral premalignant lesions, which were investigated were leukoplakia, erythroplakia, erythro-leukoplakia and verrucous hyperplasia. Reported number of premalignant lesions ranged between 5 and 225. Laser wavelength, duration of irradiation and power density were 585-660nm, 60s to 16.6min and 100-150mW/cm(2), respectively. Aminolevulinic acid, chlorine-e6, meta-tetrahydroxyphenylchlorin and photofrin were used as photosensitizer. The frequency of PDT application ranged between once and 12 times. Complete, partial and no response to PDT was shown by 27-100%, 5-50% and 0-25% of pre-malignant lesions, respectively. The recurrence rate of pre-malignant lesions was up to 36%.

CONCLUSION

PDT is effective in the overall management of oral premalignant lesions.

Is photodynamic therapy with adjunctive non-surgical periodontal therapy effective in the treatment of periodontal disease under immunocompromised conditions?

The aim was to assess whether or not photodynamic therapy (PDT) with adjunctive scaling-and-root-planing (SRP) is effective in the treatment of periodontitis under immunocompromised conditions. PubMed/Medline and Google-Scholar databases were searched from 1967 to May 2013 using various key words. Six studies (five experimental and one clinical) were included. In the clinical study, SRP with PDT was reported to be ineffective in treating chronic periodontitis in T2DM patients. All experimental studies reported significantly less bone loss in periodontal defects treated with SRP+PDT than those treated with SRP alone. Efficacy of PDT+SRP in the treatment of periodontal disease under immunocompromised conditions remains unclear.

A short-term evaluation of Nd:YAG laser as an adjunct to scaling and root planing in the treatment of periodontal inflammation

BACKGROUND

This split-mouth, single-masked, randomized, controlled clinical trial compares the short-term outcomes of a combined treatment with scaling and root planing (SRP) and neodymium-doped:yttrium, aluminum, and garnet (Nd:YAG)-laser irradiation with treatment with SRP alone.

METHODS

Thirty patients were recruited. The mandibular left or right side was randomly assigned as the test side (SRP with laser treatment) or control side (SRP alone). The water-cooled Nd:YAG laser was used at 4 W, 80 mJ/pulse, 50 Hz, and with a pulse width of 350 micros. At baseline, gingival crevicular fluid (GCF) samples were taken from the test and control sides, and levels of matrix metalloproteinase (MMP)-8 and interleukin (IL)-1beta, -4, -6, and -8 were measured using standard techniques. The plaque index (PI), gingival index (GI), and probing depth (PD) were measured by calibrated examiners.

RESULTS

At the 1-week follow-up, PD (P <0.001), PI (P <0.05), and GCF volume (P <0.001) showed significant improvement on test sides compared to control sides. At the 3-month follow-up, PD (P <0.01), PI (P <0.01), GI (P <0.01), and GCF volume (P <0.05) also showed significant improvement on test sides compared to control sides. At the 1-week follow up, IL-1beta and MMP-8 levels were significantly reduced on test sides compared to control sides. The 3-month follow-up confirmed that the improvements on test sites had been sustained compared to the treatment outcomes of control sites.

CONCLUSION

In the short-term, SRP in combination with a single application of a water-cooled Nd:YAG laser significantly improves clinical signs associated with periodontal inflammation compared to treatment with SRP alone.

The importance of coherence length in laser phototherapy of gingival inflammation—a pilot study

The aim of this study was to investigate if coherence length is of importance in laser phototherapy. Twenty patients with moderate periodontitis were selected. After oral hygiene instructions, scaling and root planing (SRP), one side of the upper jaw was randomly selected for HeNe (632.8 nm, 3 mW) or InGaAlP (650 nm, 3 mW) laser irradiation. One week after SRP, the following parameters were measured: pocket depth, gingival index, plaque index, gingival crevicular fluid volume, matrix metalloproteinase (MMP-8), interleukin (IL-8) and subgingival microflora. The irradiation (180 s per point, energy 0.54 J) was then performed once a week for 6 weeks. At the follow up examination, all clinical parameters had improved significantly in both groups. A more pronounced decrease of clinical inflammation was observed after HeNe treatment. MMP-8 levels were considerably reduced on the HeNe side, while there was no difference for IL-8 or microflora. Coherence length appears to be an important factor in laser phototherapy.

The short-term effects of low-level lasers as adjunct therapy in the treatment of periodontal inflammation

OBJECTIVES

The aim of this split-mouth, double-blind controlled clinical trial was to study the effects of irradiation with low-level lasers as an adjunctive treatment of inflamed gingival tissue.

MATERIALS AND METHODS

Seventeen patients with moderate periodontitis were included. After clinical examination, all teeth were scaled and root planed (SRP). One week after SRP, we took samples of gingival crevicular fluid (GCF) and subgingival plaque. The laser therapy was started 1 week later and continued once a week for 6 weeks. One side of the upper jaw was treated with active laser and the other with a placebo. The test side was treated with two low-level lasers having wavelengths of 635 and 830 nm. The patients then underwent another clinical examination with sampling of GCF and plaque. The GCF samples were analysed for elastase activity, interleukin-1beta (IL-1beta) and metalloproteinase-8 (MMP-8). We examined the subgingival plaque for 12 bacteria using DNA probes.

RESULTS

The clinical variables i.e. probing pocket depth, plaque and gingival indices were reduced more on the laser side than on the placebo one (p<0.01). The decrease in GCF volume was also greater on the laser side, 0, 12 microl, than on the placebo side, 0.05 microl (p=0.01). The total amount of MMP-8 increased on the placebo side but was slightly lower on the laser side (p=0.052). Elastase activity, IL-1beta concentration and the microbiological analyses showed no significant differences between the laser and placebo sides.

CONCLUSION

Additional treatment with low-level lasers reduced periodontal gingival inflammation.