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Matthias Folwaczny

Publications and source records attributed to Matthias Folwaczny.

26 records · Page 2Linked to original sources
PubMed2003

Effects of 2.94 microm Er:YAG laser radiation on root surfaces treated in situ: a histological study.

BACKGROUND: Previous scanning electron microscopy (SEM) studies using extracted teeth have shown the potential of infrared Er:YAG laser radiation to remove subgingival calculus without causing severe thermal changes, e.g., charring or fusion, to the irradiated root surface. The purpose of the present study was to examine the morphologic changes on root surfaces following Er:YAG laser irradiation in situ using histological observation. METHODS: The periodontal pockets of 6 premolars, canines, and incisors that remained in situ in the jaws of human corpses were irradiated with Er:YAG laser radiation at 60 mJ, 100 mJ, or 180 mJ. The pockets were treated in a similar manner to normal clinical circumstances with a total amount of either 50 or 100 laser pulses. Following laser treatment, the entire tooth, marginal gingiva, and underlying alveolar bone were removed from the jaw. The sections were embedded in methyl-methacrylate, serially cross-sectioned, stained with hematoxylin and eosin or gallamine blue, and examined under a light microscope. Additionally, the extension of the thermally changed tissue areas was determined using digital images and histometry. RESULTS: The histological examination revealed two kinds of thermal changes within the laser-treated root surface. Firstly, a thin superficial layer 5 to 10 microm in width was observed. The surface of this layer showed ultrastructural irregularities. Secondly, a semicircular more deeply stained area close to the apical end of the scaling track beneath the irradiated cementum was observed. The depth of this area ranged from 255 microm to 611 microm and appeared to be independent of the radiation energy. CONCLUSION: In contrast to previous SEM studies, the histological examination indicated thermal changes within the hard tissue bordering the periodontal pocket following Er:YAG laser irradiation.

Aluminum Silicates↗
PubMed2003

Removal of bacterial endotoxin from root surface with Er:YAG laser.

PURPOSE: To determine the potential of 2.94 microm Er:YAG laser radiation to remove bacterial endotoxin from root surfaces. MATERIALS AND METHODS: 40 extracted teeth were divided into four groups of 10 samples each. A 16 mm2 area of the root surface on each sample was inoculated with an aliquot of 7 microl of a lipopolysaccharide suspension at a concentration of 50 IU/ml. LPS was derived from a non-oral Escherichia coli strain (E. coli 055:B5). Source of laser radiation was an Er:YAG laser emitting pulsed infrared radiation at a wavelength of 2.94 microm, with a pulse duration of 250 micros, and a pulse repetition rate of 15 pps. Three specimen groups were irradiated with 105 laser pulses at a radiation energy of 60 mJ, 100 mJ and 140 mJ. One specimen group was untreated (control). The LPS concentration with each sample was determined using a chromogenic, quantitative Limulus-amoebocyte-lysate assay. Statistical analysis was ANOVA and Scheffé-test. RESULTS: Mean LPS yield from the untreated control samples was 50.1 (+/- 35.9) IU/ml. Following laser irradiation the average LPS on the root surfaces was 19.86 (+/- 14.4) IU/ml at 60 mJ, 12.86 (+/- 8.1) IU/ml at 100 mJ and 8.58 (+/- 4.9) IU/ml at 140 mJ.

Decontamination↗
PubMed2002

Antimicrobial effects of 2.94 microm Er:YAG laser radiation on root surfaces: an in vitro study.

OBJECTIVES: This in vitro study investigated the antimicrobial effects of 2.94 microm Er:YAG laser radiation on root surfaces. MATERIALS AND METHODS: The study used 125 extracted teeth which were divided into 2 groups (A, B) of 40 teeth and 3 groups of 15 teeth (C, D, E). A defined and similarly-sized area of the root surface was inoculated with an aliquot of 7 microl of a bacterial suspension of Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), Actinobacillus actinomycetemcomitans (ATCC 43719), Eikenella corrodens (ATCC 51724), or Peptostreptococcus micros (ATCC 33270). Subsequently, the samples from each group were further divided into subgroups which have been irradiated either with 55, 75, and 105 (group A, B) or 55 and 75 (group C, D, E) laser pulses. 1 subgroup of each group was left untreated as control. The source of laser radiation was an Er:YAG laser emitting pulsed infrared radiation at a wavelength of 2.94 microm. The number of bacteria was determined using the surface spread plate technique. The statistical analysis was performed using ANOVA followed by the Scheffé-test. RESULTS: Depending on the number of laser pulses the bacterial load in the E. coli group was reduced by the Er:YAG laser radiation after exposure to 105 laser pulses to 5.5% of the initial count and that in the Staph. aureus group to 15.1%. The number of bacteria in case of A. actinomytemcomitans was reduced to 8.3%, in case of E. corrodens to 3.0% and in case of P. micros to 22.0% after application of 75 laser pulses. CONCLUSION: Besides the selective removal of plaque and calculus, the 2.94 microm Er:YAG laser radiation causes reduction in bacteria on root surfaces.

Aggregatibacter actinomycetemcomitans↗
PubMed2002

Root surface roughness following Er:YAG laser irradiation at different radiation energies and working tip angulations.

OBJECTIVES: The determination of roughness of root surfaces following treatment with 2.94 micro m Er:YAG laser radiation at different radiation energies and working tip angulations. MATERIALS AND METHODS: The study sample comprised 85 extracted human molars, premolars, canines and incisors (n = 85). The source of laser radiation was an Er:YAG laser device (KAVO-Key II, System Aesculap Meditec) emitting pulsed infrared radiation at a wavelength of 2.94 micro m, with a pulse duration of 250 micro s, and a pulse repetition rate of 10 pps. The samples were randomly divided into three experimental units, for treatment with a constant amount of 380 laser pulses at a radiation energy of 60 mJ, 100 mJ, and 180 mJ. Each experimental unit was divided into five subgroups of five samples, which were irradiated at a working tip angulations of 15 degrees, 30 degrees, 45 degrees, 60 degrees, and 90 degrees. Five samples were treated mechanically using curettes. Five samples were left untreated as control. The mean (Ra) and maximum (Rmax) surface roughness of each sample was measured using a profilometer. The statistical analysis was undertaken using anova and Scheffé-test at a level of significance of 5% (p < 0.05). RESULTS: Er:YAG laser radiation led to an Ra which ranged from 0.52 micro m (+/- 0.10) to 0.81 micro m (+/- 0.26) and to an Rmax between 3.4 micro m (+/- 0.48) and 9.26 micro m (+/- 3.08). The Ra and Rmax for samples treated with curettes was 0.51 micro m (+/- 0.11) and 5.08 micro m (+/- 4.98), respectively. That for the untreated control samples were 0.53 micro m (+/- 0.15) and 7.07 micro m (+/- 5.48), respectively. CONCLUSIONS: The mean and maximum surface roughness of root surfaces following irradiation with Er:YAG laser was not significantly different to that obtained on samples treated with conventional hand instruments or left untreated. Furthermore, the surface roughness does not depend on the radiation energy and the angulation of the working tip.

Aluminum Silicates↗
PubMed2002

Antibacterial effects of pulsed Nd:YAG laser radiation at different energy settings in root canals.

The in vitro study aimed at the determination of the bacterial reduction in root canals used pulsed Nd:YAG laser radiation without a photosensitizing dye. In addition the temperature change in the root canals was determined during laser irradiation. The study sample was 114 root canals of extracted single-rooted human teeth that have been enlarged mechanically, sterilized, and randomly assigned to two experimental units. The source of radiation was a Nd:YAG laser device emitting pulsed infrared radiation at a wavelength of 1.064 microm, a pulse duration of 100 micros, and a pulse repetition rate of 20 pps. Samples of each experimental unit were inoculated with Escherichia coli (ATCC 25922) or Staphylococcus aureus (ATCC 25923), respectively, and divided into subgroups of 13 teeth each for irradiation for 20 s at 100 mJ or 200 mJ. One subgroup was left untreated as positive control and one subgroup was rinsed with 0.5 ml of sodium hypochloride. After laser treatment or rinsing with sodium hypochloride the number of bacteria in each root canal was determined using the surface spread plate technique. Statistical analysis of the results was performed with ANOVA and Scheffé test at a level of significance of 5% (p < 0.05). In case of E. coli the number of bacteria was reduced from 8.67 x 10(6) (+/-4.11 x 10(5)) colony-forming units (CFU)/ml to 4.39 x 10(4) (+/-1.72 x 10(4)) CFU/ml after laser radiation at 200 mJ. Regarding S. aureus the number of bacteria decreased from 1.44 x 10(6) (+/-1.59 x 10(5)) CFU/ml to 3.8 x 10(4) (+/-1.06 x 10(4)) CFU/ml at a radiation energy of 200 mJ. Rinsing with sodium hypochloride reduced the number of bacteria to 1.03 x 10(3) (+/-4.02 x 10(2)) CFU/ml regarding E. coli and to 1.84 x 10(3) (+/-7.4 x 10(2)) CFU/ml in case of S. aureus. The temperature increase at 100 mJ was 24.3 degrees C (+/-3.9) and that at 200 mJ was 61.8 degrees C (+/-4.2). The Nd:YAG laser radiation has antimicrobial effects in root canals even in the absence of photosensitizing dyes but also causes considerable temperature increase.

Aluminum Silicates↗
PubMed2002

Subgingival calculus detection with fluorescence induced by 655 nm InGaAsP diode laser radiation.

BACKGROUND: It has been suggested that the 655 nm InGaAsP diode laser radiation can induce considerably higher amounts of fluorescence in subgingival calculus than in cementum. This in vitro study evaluated the use of fluorescence induced by the diode laser radiation for the detection of subgingival calculus. METHODS: The study sample consisted of 30 extracted molars, premolars, canines, and incisors. The root surface of each sample was partially covered with subgingival calculus. The source of laser radiation was an InGaAsP diode laser emitting visible radiation at a wavelength of 655 nm. The fluorescent radiation reflected from the cementum and calculus was detected by a photoelectric cell integrated within the diagnostic system. The samples were randomly assigned to 3 experimental groups of 10 teeth each for detection of calculus in various media. Specifically, the fluorescence was determined in air (group A), in electrolytic salt solution (group B), and in blood (group C). For each sample, the intensity of the fluorescent light was evaluated separately for cementum and calculus in triplicate measurements. The statistical analysis was performed using a t test at a level of significance of 5% (P<0.05). RESULTS: The intensities of fluorescence radiation emitted by cementum were 0.4 (+/-0.51) in air, 0.4 (+/-0.51) in electrolytic solution, and 2.13 (+/-0.59) in blood. For calculus, the relative intensities of fluorescence radiation were 54.1 (+/-29.09) in air, 60.77 (+/-28.35) in electrolytic salt solution, and 39.63 (+/-29.79) in blood. The differences in fluorescence between cementum and calculus within each experimental unit were significant (group A: P= 0.0002, group B: P= 0.0001, group C: P= 0.031). The intensity of fluorescence in calculus was also significantly different between the 3 experimental groups. CONCLUSION: The present study indicates that subgingival calculus can be reliably detected on extracted teeth using laser fluorescence induced by the 655 nm diode-laser radiation. In vivo studies are necessary to evaluate the clinical utility of this procedure.

Dental Calculus↗