Biomedical subjects

M Folwaczny

Publications and source records attributed to M Folwaczny.

27 records · Page 2Linked to original sources

PubMed1999

Bactericidal effects of 2.94 microns Er:YAG-laser radiation in dental root canals.

The purpose of this study was to investigate the antimicrobial properties of Er:YAG-laser radiation in dental root canals. The root canals of 90 freshly extracted anterior teeth were enlarged mechanically, sterilized, and randomly divided into subgroups of 10 samples. The root canals were inoculated with Escherichia coli or Staphylococcus aureus for 2 h. The laser treatment groups were exposed for either 15 or 60 s to Er:YAG-laser radiation (pulse energy: 50 mJ; 15 pps). Additionally, for each bacterial strain, one sample group was rinsed with a NaOCl solution (1.25%), and one was left untreated as control. After irradiation or irrigation, the number of bacteria was evaluated using the surface spread plate technique. In the case of S. aureus, the primary bacterial load (control group) of the root canals was reduced to 0.15% after 15 s and 0.06% after 60 s of laser treatment. In the E. coli group, the number of bacteria was diminished to 0.13%, with the shorter radiation time and to 0.034% after 60 s of radiation. Irrigating the root canals with NaOCl, a reduction of the number of bacteria to 0.033% for S. aureus and to 0.020% for E. coli could be obtained. As the results confirm, Er:YAG-laser radiation exerts very effective antimicrobial properties in dental root canals, depending on the time of radiation.

Colony Count, Microbial↗

PubMed1999

Substance removal on teeth with and without calculus using 308 nm XeCl excimer laser radiation. An in vitro investigation.

It was the aim of this in vitro study to determine the potential effects of 308 nm XeCl excimer laser radiation on root surfaces when used for removing calcified deposits. The source of laser radiation was a XeCl-excimer laser (MAX 10, Fa. Medolas, Germany) emitting ultraviolet radiation at a wavelength of 308 nm with a pulse duration of 60 ns. Subjects of irradiation were 60 extracted teeth which were divided into 2 groups of 30 samples each with (group 1) and without calculus (group 2). Specimens were irradiated with 800 laser pulses at 5 different energy-densities per pulse of 1.0 J/cm2, 2.0 J/cm2, 3.0 J/cm2, 4.0 J/cm2 and 5.0 J/cm2. For each parameter 6 samples (n=6) were exposed to 308 nm excimer-laser radiation. The ablation of hard tissue on the treated root surfaces was measured 3-dimensionally with a laser scanning device (100,000 surface points per sample; accuracy: 5 microm) and evaluated with a special image analyzing software (volume, mean, median, standard deviation). In addition, a scanning electron microscopic (SEM) evaluation of the irradiated root surfaces was performed. Statistical analysis was done using ANOVA with the Scheffé-test. The lowest amount of ablation on teeth without calculus was induced with 14.01 (+/-5.86) microm using laser radiation at an energy density of 2.0 J/cm2. Maximum tissue removal in this sample group was obtained with 56.67 (+/-21.05) microm with laser treatment at an energy density of 5.0 J/cm2. While no ablation of dental cementum was detectable after irradiating root surfaces without calculus at 1.0 J/cm2, a strong removal of calculus with a mean value of 31.91 (+/-4.2) microm was observed under these conditions. The results seem to indicate that a selective removal of subgingival calculus creating a homogenous shape of the root surface with 308 nm excimer laser radiation is possible. Furthermore, no signs of the formation of a smear layer nor the induction of thermal side-effects were observed.

Analysis of Variance↗

PubMed1998

[Oro-dental injuries during intubation anesthesia].

Injuries to the oro-dental tissue are still one of the most frequent mishaps during endotracheal intubation and general anaesthesia. However, damage to the soft and hard tissues in most cases involves oral structures already showing advanced pathogenic alterations. Injuries to the teeth are therefore rather more often due to the disease of the teeth than to mistakes during anaesthesia. The risk of injuries to the teeth can be ascertained by means of a presurgical inspection of the oral cavity and evaluation of the individual anatomical conditions in the head and neck region, which may well interfere with the endotracheal intubation. In contrast to anaesthetic pitfalls causing severe disturbance of general health, dental trauma can be treated with quite satisfying functional and aesthetic results. However, in order to maintain conditions for the complete restitution of injured teeth immediate dental therapy is recommended. In preterm infants which need mechanical ventilation during the postnatal period direct laryngoscopy as well as mechanical alterations caused by an oral tube can cause injuries to the tooth germs of the first and second dentition and deformation of the maxillary skeleton. In consequence the patient will need intensive therapy of the resulting disturbances for several years. This review gives information about the causes and types of injuries to the oral and maxillofacial region during general anaesthesia. In addition, the anatomical conditions and pathological changes associated with an increased risk for oro-dental injuries and the facilities for prevention are discussed. Finally, the main aspects of emergency treatment of injuries to the dental hard tissues are presented.

Anesthesia, Inhalation↗

PubMed1998

Bactericidal action of 308 nm excimer-laser radiation: an in vitro investigation.

The aim of the present study was to investigate the influence of 308 nm excimer-laser radiation on bacterial growth. Six different bacterial strains (Staphylococcus aureus, Escherichia coli, Streptococcus faecalis, Lactococcis lactis, Salmonella typhimurium, and Deinococcus radiodurans) were exposed in vitro to various doses and energy densities of laser radiation. To exclude bacterial killing by supraphysiological heating, the temperature change in the samples during irradiation was measured. Extended antimicrobial effects of XeCl excimer-laser radiation depending on the time of radiation, the energy density of the laser beam, and the irradiated bacterial strain were observed. Reduction of bacterial growth is independent of temperature and not linked to any ablative tissue removal. In almost all cases, a 99.9% reduction of bacteria was reached by total radiation times < 100 ms. The proven antimicrobial effects of 308 nm excimer-laser radiation may be of significant clinical importance in endodontics and periodontology in the future.

Analysis of Variance↗

PubMed1998

Polishing and coating of dental ceramic materials with 308 nm XeCl excimer laser radiation.

OBJECTIVES: The polishing and coating of ceramic surfaces is recommended in order to improve the physical properties of dental ceramics. Conventional methods for the surface treatment of dental ceramic materials are not capable of creating a smooth surface without microcracks. The special radiation characteristics of XeCl excimer laser light indicate that it must be possible to treat ceramic surfaces in order to produce a polished finish. The aim of this study was to investigate the efficacy of XeCl excimer laser radiation for the polishing and coating of dental ceramics. METHODS: Samples (n = 64) of four different dental ceramic materials were irradiated with 308 nm XeCl excimer laser radiation at varying energy densities per laser pulse of 1.57, 3.14, and 6.28 J cm-2. In detail, the subjects for irradiation were samples of Ivoclar-Empress (leucite-reinforced feldspathic ceramic), In-Ceram Spinell (double crystalline spinell ceramic), In-Ceram Alumina (alumina oxide; continous interpenetrating phase composite ceramic) and Vita-Mark II (feldspathic ceramic). The roughness (Ra) of the laser-treated ceramic surfaces was measured using a profilometer. In addition, SEM and AFM investigations of the changes in surface structure were conducted. The changes in surface roughness due to laser treatment were analyzed for their statistical significance using ANOVA with the Scheffé test at a level of significance of 0.05% (p < 0.05). Depending on the type of ceramic material and the energy density of the radiation, varying reductions of the surface roughness were obtained. In general, minimum values of the roughness were measured on samples irradiated with maximum energy density of radiation. RESULTS: The lowest roughness value was obtained for the specimen of In-Ceram Spinell: 1.30 (+/- 0.19) microns. The mean value for minimal roughness of Ivoclar-Empress was 1.92 (+/- 0.35) microns, that for In-Ceram Alumina was 2.04 (+/- 0.49) microns, and that for Vita-Mark II was 2.72 (+/- 0.40) microns. Ultrastructural examination of laser-treated ceramics in part demonstrated both extensive fusion and inhomogeneous surfaces with blistering and the formation of microcracks. SIGNIFICANCE: It is concluded that the physical roughness of dental ceramic surfaces can be significantly reduced by 308 nm excimer laser irradiation. Nevertheless, the laser-treated surface was in no case completely fused and the formation of microcracks and blistering was observed. Therefore, after using an XeCl excimer laser for finishing dental ceramic alloys, further polishing of the laser-treated ceramic surfaces will be needed.

Aluminum Oxide↗

PubMed1996

[Osteomyelitis sicca in Crohn disease--coincidence or extraintestinal manifestation?].

In patients with Crohn's disease arthritis of the large joints, osteomalacia, osteoporosis and aseptic bone necrosis as a consequence of malabsorption and glucocorticoid intake may occur. The case of a patient with long-standing Crohn's disease is presented who subsequently developed abacterial osteomyelitis of the jaw ("osteomyelitis sicca"). The symptoms of the osteomyelitis improved under immuno-suppressive therapy. Because the etiopathogenetic concepts for Crohn's disease and osteomyelitis sicca are similar, the latter could be a rare extraintestinal manifestation in Crohn's disease, not described previously.

Adult↗

PubMedDate not supplied

Toxicokinetic of HEMA in guinea pigs.

OBJECTIVE: Unconverted 2-hydroxyethylmethacrylate (HEMA) can be released from dental resin materials and can enter the body in humans. In the present study the uptake, distribution and excretion of 14C-HEMA applied via different routes were examined in vivo in guinea pigs. METHODS: HEMA (0.02 mmol/kg bw labelled with a tracer dose 14C-HEMA 0.3 Bq/g bw) was administered by gastric tube or by subcutaneous injection. Urine, feces, and exhaled carbon dioxide were collected for 24 h after administration. Guinea pigs were killed 24 h after the beginning of the experiment and various organs removed and 14C radioactivity measured. RESULTS: Low fecal 14C levels (about 2% of the dose) and urinary levels of about 15% after 24 h were noted with either route of administration. Direct measurement of exhaled CO(2) showed that about 70% of the dose left the body via the lungs. Two pathways for the metabolism of 14C-HEMA can be described. It is likely that 14C-pyruvate is formed in vivo resulting in the formation of toxic 14C-HEMA intermediates. 14C-HEMA was taken up rapidly from the stomach and small intestine after gastric administration and was widely distributed in the body following administration by each of the routes. CONCLUSIONS: Clearance from most tissues following gastric and intradermal administration was essentially complete within one day. The peak HEMA levels in all tissues examined after 24 h were at least onemillion-fold less than known toxic levels.

Acrylic Resins↗

PubMedDate not supplied

Tooth-colored filling materials for the restoration of cervical lesions: a 24-month follow-up study.

The recently developed resin-modified glass ionomer cements and the polyacid-modified composites are promising alternatives to conventional materials for restoring cervical defects. This clinical study evaluated the clinical condition of cervical fillings 24 months following placement. The study subjects were 197 cervical restorations placed on incisors, canines and premolars in 37 patients for restoration of erosion/non-carious lesions (69 cases), primary carious lesions (57 cases) and the replacement of deficient restorations (71 cases). The teeth were randomly divided into four groups for restoration with either Tetric (composite, Group A: n = 36), Dyract (compomer, Group B: n = 79), Fuji II LC (resin-modified glass ionomer cement, Group C: n = 51) or Photac-Fil (resin-modified glass ionomer cement, Group D: n = 31). The evaluation was done single-blind at baseline, 8 and 24 months after the placement of the fillings, according to a modified USPHS rating scale. The assessment criteria were color stability, anatomical form, surface texture, marginal integrity, marginal discoloration and loss of filling. Statistical analysis was completed using Pearson chi-square and Fisher's exact test at a significance level of 5% (p < 0.05). After the 24-month period, the composite restorations showed superior results. The compomer fillings demonstrated conditions that were only slightly worse. A substantial number of the resin-modified glass-ionomer fillings were evaluated with bravo or even charlie scores in respect to at least one of the criteria assessed.

Adult↗

PubMedDate not supplied

Impaired dentofacial development after radiotherapy of a non-Hodgkin lymphoma: report of case.

Since the advances in therapy of childhood malignancies have improved life expectancy attention is now increasingly focused on the long-term effects of antineoplastic therapy. Developmental abnormalities due to antineoplastic therapy have been claimed to preferentially occur in children treated before the age of six years. This report of a case demonstrates severe developmental disturbances following radiotherapy of a cervical non-Hodgkin lymphoma at the age of eight years. The morphological changes included microdontia, root shortening, blunting and thinning as well as mandibular hypoplasia.

Adult↗