0000000000223522
AUTHOR
Matthias Kreisler
Low level 809-nm diode laser-induced in vitro stimulation of the proliferation of human gingival fibroblasts
Background and Objective The authors investigated the effects of low level laser irradiation on the proliferation rate of human gingival fibroblasts (HGF) in vitro. Study Design/Materials and Methods HGF were obtained from gingival connective tissue explants and cultured under standard conditions. 110 cell cultures in their logarithmic growth phase were spread on 96-well tissue culture plates and were irradiated at energy fluences of 1.96–7.84 J/cm2. Another 110 cultures served as control. An 809-nm semiconductor laser operated at a power output of 10 mW in the cw-mode was used. The time of exposure varied between 75 and 300 seconds. Laser treatment was performed alternatively once, twice, …
Low-level 809 nm GaAlAs laser irradiation increases the proliferation rate of human laryngeal carcinoma cells in vitro
The aim of the study was to investigate the effect of low-level 809 nm laser irradiation on the proliferation rate of human larynx carcinoma cells in vitro. Epithelial tumor cells were obtained from a laryngeal carcinoma and cultured under standard conditions. For laser treatment the cells were spread on 96-well tissue culture plates. Sixty-six cell cultures were irradiated with an 809 nm GaAlAs laser. Another 66 served as controls. Power output was 10 mW(cw) and the time of exposure 75–300 s per well, corresponding to an energy fluence of 1.96–7.84 J/cm2. Subsequent to laser treatment, the cultures were incubated for 72 h. The proliferation rate was determined by means of fluorescence acti…
In vitro evaluation of the biocompatibility of contaminated implant surfaces treated with an Er : YAG laser and an air powder system
Abstract: Titanium platelets with a sand-blasted and acid-etched surface were coated with bovine serum albumin and incubated with a suspension of Porphyromonas gingivalis (ATCC 33277). Four groups with a total of 48 specimens were formed. Laser irradiation of the specimens (n=12) was performed on a computer-controlled XY translation stage at pulse energy 60 mJ and frequency 10 pps. Twelve specimens were treated with an air powder system. After the respective treatment, human gingival fibroblasts were incubated on the specimens. The proliferation rate was determined by means of fluorescence activity of a redox indicator (Alamar Blue® Assay) which is reduced by metabolic activity related to c…
Effect of diode laser irradiation on the attachment rate of periodontal ligament cells: an in vitro study.
The present study is part of a basic research program investigating the cellular effects of an 810 nm GaAlAs-diode laser on human periodontal tissues. The aim of the investigation was to evaluate the effects of laser treatment of root surface specimens on the attachment of periodontal ligament (PDL) cells in vitro.Root specimens were prepared from periodontally diseased teeth. PDL cells were obtained from human third molar ligaments. Cells were cultured under simple, standardized, and reproducible experimental conditions. One hundred fifty root specimens were scaled and root planed with curets followed by air-powder abrasive treatment; 75 were then lased and 75 served as controls. The irrad…
Efficacy of low level laser therapy in reducing postoperative pain after endodontic surgery-- a randomized double blind clinical study.
The aim of the study was to evaluate the effect of low level laser application on postoperative pain after endodontic surgery in a double blind, randomized clinical study. Fifty-two healthy adults undergoing endodontic surgery were included into the study. Subsequently to suturing, 26 patients had the operation site treated with an 809 nm-GaAlAs-laser (oralaser voxx, Oralia GmbH, Konstanz, Germany) at a power output of 50 mW and an irradiation time of 150 s. Laser treatment was simulated in further 26 patients. Patients were instructed to evaluate their postoperative pain on 7 days after surgery by means of a visual analogue scale (VAS). The results revealed that the pain level in the laser…
Efficacy of NaOCl/H2O2irrigation and GaAlAs laser in decontamination of root canals in vitro
Background and Objectives To investigate the bactericidal effect of an 809 nm semiconductor laser alone, and in combination with NaOCl/H2O2 irrigation in root canals in vitro. Study Design/Materials and Methods A total of 72 human single-rooted teeth extracted for periodontal reasons were included. The crowns were removed, the roots shortened to a length of 12 mm, and the canals enlarged up to an apical size of #50 file. The specimens were autoclaved and incubated with a suspension of Streptococcus sanguinis (ATCC 10556). Laser irradiation was performed on a PC-controlled XY translation stage. A 200 micron optic fiber was used. Twelve specimens were irradiated at a power output of 1.5, 3.0,…
Clinical evaluation of a modified marginal sulcular incision technique in endodontic surgery
The authors evaluated periodontal parameters following apical surgery using a new marginal sulcular incision. In 65 cases, surgical access was achieved by means of a sulcular incision technique without the involvement of the adjacent periodontia and the interproximal papillae and in 33 cases by means of a submarginal trapezoidal technique. Periodontal parameters (probing pocket depth, gingival recession, clinical attachment loss, and tooth mobility [periotest]) were recorded at baseline and after 6 months. Scar formation and the loss of papilla height were evaluated photographically. No significant changes in the attachment level and no loss of papilla height were found in either group. A s…
Intrapulpal temperature changes during root surface irradiation with an 809-nm GaAlAs laser
The aim of this study was to explore, in vitro, whether the irradiation of human root surfaces with a diode laser might induce nonphysiologic intrapulpal temperature elevations and, therefore, jeopardize pulp vitality.The pulps were removed from human maxillary and mandibular incisors extracted for periodontal reasons. The root canals were enlarged to an apical size #60 file. The teeth were radiographed with standard dental films and a millimeter grid to determine root thickness. The thickness of dentin between the root surface and the pulp in the irradiation areas was 1, 2, and 3 mm. To determine intrapulpal temperature changes during laser irradiation, 0.5-mm K-type thermocouples were ins…
Effect of diode laser irradiation on root surfaces in vitro.
The objective of this study was to evaluate possible morphological alterations of root surfaces after GaAlAs-diode laser (809 nm) irradiation under standardized in vitro conditions.Root specimens obtained from extracted periodontally diseased teeth were scaled and root planed with curettes followed by air-powder abrasive treatment prior to lasing. The variable parameters were power output (0.5-2.5 W) and exposure time (10-30 sec per specimen). Additionally, the effect of a saline solution and a human blood film on the root surface was investigated. The root segments were analyzed by means of a reflected light microscope. Photographs before and after irradiation were taken and evaluated. The…
Effect of diode laser irradiation on the survival rate of gingival fibroblast cell cultures
Background and Objective The present study is part of a basic research program investigating the cellular effects of the GaAlAs-diode laser with a wavelength of 810 nm on human periodontal tissues. The aim of the investigation was to evaluate the effects of the laser treatment on the survival rate of human gingival fibroblasts (HGF) in monolayer cell culture at different power settings and durations. Study Design/Materials and Methods HGF were obtained from a human gingival connective tissue explant. Cells were cultured on 24-well tissue culture plates. One hundred and thirty multi well cell cultures were laser treated. The variable parameters were power output (0.5–2.5 W) and exposure time…
Temperature changes induced by 809-nm GaAlAs laser at the implant-bone interface during simulated surface decontamination
The aim of the study was to investigate temperature changes at the implant-bone interface during simulated implant surface decontamination with a 809-nm gallium-aluminium-arsenid (GaAlAs) semiconductor laser. Stepped cylinder implants with a diameter of 3.8 mm and a length of 11 mm with two different surfaces (sand-blasted and acid etched, and hydroxyapatite-coated) were inserted into bone blocks cut from freshly resected pig femurs. Access holes of 0.5 mm were drilled into the bone, to allow K-type thermocouples to contact periimplant bone in different parts of the cavity. An artificial periimplant bone defect provided access for laser irradiation in the coronal third. A 600-micrometer opt…
Effect of simulated CO2and GaAlAs laser surface decontamination on temperature changes in Ti-plasma sprayed dental implants
Background and Objective To investigate and compare temperature elevations at the implant-bone interface during simulated implant surface decontamination with a CO2 and a GaAlAs laser. Study Design/Materials and Methods Stepped cylinder implants (Frialit 2® Friadent GmbH, Mannheim, Germany) with a Titanium plasma sprayed surface were inserted into bone blocks cut from pig femurs. An artificial periimplant bone defect provided access for laser irradiation in the coronal third. Both lasers were operated at 1.0–2.5 W in the cw-mode. The bone block was placed into a 37°C water bath in order to simulate in vivo thermal conductivity and diffusitivity of heat. K-type thermocouples connected to a d…
Efficacy of Subgingival Irrigation Using Herbal Extracts on Gingival Inflammation
The aim of the present study was to investigate the efficacy of an herbal-based mouthrinse in combination with an oral irrigator in reducing gingival inflammation.A total of 89 patients (45 females, 44 males; mean age 49.1 +/- 1.31 years) were included in this prospective, randomized, double-blind clinical study and allocated to 3 treatment groups: group 1 (n = 34), treated with an oral irrigator with subgingival tips and an herbal-based mouthrinse; group 2 (n = 29), the oral irrigator was applied in combination with a conventional mouthwash; and group 3 (n = 26), treated with the conventional mouthwash without subgingival irrigation. Data collected at baseline and after 4, 8, and 12 weeks …
Bactericidal Effect of the Er:YAG Laser on Dental Implant Surfaces: An In Vitro Study
The aim of the in vitro study was to examine the bactericidal effect of an Er:YAG laser on common dental implant surfaces.Seventy-two titanium platelets with 3 different surfaces--sandblasted and acid-etched (SA), titanium plasma-sprayed (TPS), and hydroxyapatite-coated (HA)--were incubated with a suspension of Streptococcus sanguinis (ATCC 10556). Irradiation at pulse energies of 60 and 120 mJ and a frequency of 10 pps was performed on a computer-controlled XY translation stage. After laser treatment the specimens were sonicated and the bacterial growth examined by counting colony forming units on blood agar plates. Temperature elevations during irradiation were investigated using K-type t…
Clinical efficacy of semiconductor laser application as an adjunct to conventional scaling and root planing.
Background and Objectives: The aim of the in vitro study was to examine the clinical efficacy of semiconductor laser periodontal pocket irradiation as an adjunct to conventional scaling and root planing. Materials and Methods: Twenty-two healthy patients with a need of periodontal treatment (15 women, 7 men, mean age 45.0� 10.8 years) with at least four teeth in all quadrants, were included. All of them underwent a conventional periodontal treatment including scaling and root planing. Using a split mouth design, two randomly chosen quadrants (one upper and the corresponding lower one) were subsequently treated with an 809 nm GaAlAs laser operated at a power output of 1.0 Watt using a 0.6 mm…
Effect of low-level GaAlAs laser irradiation on the proliferation rate of human periodontal ligament fibroblasts: an in vitro study
Aim: The aim of this in vitro study was to evaluate a potential stimulatory effect of low-level laser irradiation on the proliferation of human periodontal ligament fibroblasts (PDLF). Materials and Methods: PDLF obtained from third molar periodontal ligaments were cultured under standard conditions and spread on 96-well tissue culture plates. Subconfluent monolayers were irradiated with an 809-nm diode laser operated at a power output of 10 mW in the continuos wave (cw) mode at energy fluences of 1.96‐7.84 Jcm ‐2 . The variable irradiation parameters were the time of exposure (75‐300 s per well) and the number of irradiations (1‐3). After laser treatment, the cultures were incubated for 24…
Temperature elevations in endosseous dental implants and the peri-implant bone during diode-laser-assisted surface decontamination
The aim of the study was to investigate temperature elevations in the implant surface and the peri-implant bone during simulated surface decontamination of endosseous dental implants with an 809 nm semiconductor laser. Stepped cylinder implants were inserted into bone blocks cut from resected pig femurs. An artificial peri-implant bone defect provided access for the irradiation of the implant surface. A 600 micron optic fiber was used at a distance of 0.5 mm from the implant surface. Power output varied between 0.5 and 2.5 W in the cw-mode. Power density was between 176.9 and 884.6 Wcm -2 . The bone block was placed into a 37 degree(s)C water bath in order to simulate in vivo thermal conduc…