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Biomedical subjects

B Klaiber

Publications and source records attributed to B Klaiber.

At least 37 records · Page 2Linked to original sources
PubMed1996

Efficacy of systemically administered acetylsalicylic acid plus scaling on periodontal health and elastase-alpha 1-proteinase inhibitor in gingival crevicular fluid.

The purpose of this proof of principle trial was to assess whether conventional periodontal therapy and systemically administrated acetylsalicylic acid (ASA) are functionally synergistic when combined in the treatment of periodontitis. A total of 30 patients with untreated moderate to severe adult periodontitis were enrolled into the study and were given placebo q.i.d. between the baseline and 6-week examination, and acetylsalicylic acid (ASA) 500 mg q.i.d. between the 6-week and 12-week examinations. In addition, they received supra- and subgingival scaling in 1 quadrant after baseline examination and in 2 further randomly selected quadrants after the 6-week examination. The study design resulted in the following 4 therapies: (1) scaling plus ASA 500 mg q.i.d.; (2) scaling plus placebo q.i.d.; (3) ASA 500 mg q.i.d. alone; (4) placebo q.i.d. alone. Two-way analysis of variance showed functional synergism of ASA and scaling, resulting in a therapeutic efficacy approximately equivalent to the sum of each individual therapeutic efficacy (i.e., ASA alone and scaling alone) in reducing gingival inflammation and pocket probing depth over the 6-week observation period (interaction: p > 0.05). Only the effect of ASA was significant in reducing the concentration of elastase-alpha 1-proteinase inhibitor in gingival crevicular fluid (GCF E-alpha 1-PI) (p < 0.001), reduction in GCF E-alpha 1-PI concentrations by ASA may indicate a decreased risk in periodontal disease progression. The results suggest that the combination of therapies and their different mechanisms of action, i.e., reduction of bacterial plaque and inhibition of destructive components of the immune responses, may result in functionally synergistic therapeutic efficacies in patients with untreated adult periodontitis.

Administration, Oral↗
PubMed1995

Adjunctive supragingival irrigation with acetylsalicylic acid in periodontal supportive therapy.

To assess the clinical efficacy of adjunctive supragingival irrigation with buffered 0.3% acetylsalicylic acid (ASA), 60 patients with periodontitis receiving supportive periodontal therapy were randomly assigned to 1 of 3 home regimens: (1) 1x daily adjunctive supragingival irrigation with 300 ml water immediately followed by 200 ml of buffered 0.3% ASA; (2) 1x daily adjunctive supragingival irrigation with 500 ml water; or (3) normal oral hygiene alone. Clinical parameters were assessed at baseline and 6 months. Irrigator use was measured by timers built into the irrigator units. Results at 6 months showed that both supragingival irrigation with buffered 0.3% ASA and supragingival irrigation with water significantly reduced gingival index scores (median 0.1 and 0.35, respectively) and pocket probing depths (both median 0.26 mm) compared to the control group. In addition, irrigation with water resulted in a significant reduction in bleeding on probing (median 0.13), whereas irrigation with buffered 0.3% ASA had no significant effect on bleeding on probing compared to the control group. The clinical efficacy of irrigation with either ASA or water was found to be positively correlated to initial disease severity and irrigator use. Thus, frequent supragingival irrigation with either 0.3% ASA or water in addition to regular oral hygiene appears to be a beneficial adjunct to periodontal supportive therapy in patients with moderate to severe signs of periodontitis. However, the use of buffered 0.3% ASA as an irrigant does not seem to enhance the clinical efficacy of supragingival irrigation on periodontal health.

Adult↗
PubMed1995

Identification of Actinobacillus actinomycetemcomitans in subgingival plaque by PCR.

The purpose of this study was to assess the sensitivity and specificity of the PCR in detecting Actinobacillus actinomycetemcomitans. The PCR's detection capability was compared with those of three other methods: culture-enhanced PCR (CE-PCR), colony hybridization (CH), and conventional culture with presumptive biochemical identification. A 285-bp stretch of the leukotoxin gene lktA of A. actinomycetemcomitans was amplified by PCR with primers TT-15 and TT-16. For CH, the PCR product was labeled with digoxigenin and used as a hybridization probe. Nucleotide sequence analysis of the PCR product of A. actinomycetemcomitans 1D4 and 1664 and three clinical isolates revealed complete homology among the tested strains, with only one base substitution (at position 1344) in comparison with the published sequence. With artificially infected subgingival plaque, the detection limit of PCR for A. actinomycetemcomitans was 10(3) CFU/ml of plaque suspension. Culturing subgingival plaque on tryptic soy-serum-bacitracin-vancomycin agar prior to PCR (CE-PCR) improved the limit of detection to 10(2) CFU/ml. Analysis of subgingival plaque samples from 35 patients with periodontal disease and 10 periodontally healthy subjects revealed that CE-PCR and CH had the highest overall rate of A. actinomycetemcomitans detection (both 58%), followed by PCR and culture (both 42%). With CH as the "gold standard", the sensitivities of CE-PCR, PCR, and culture were 88, 65, and 58%, respectively; the specificities were 84, 89, and 79%, respectively. The CE-PCR provided acceptable positive and negative predictive values (> or = 70%) when the prevalence of A. actinomycetemcomitans varied between 30 and 70%. PCR alone provided comparable predictive values over a narrower range of prevalence rates (30 to 50%), while culture did not afford acceptable predictive values at any prevalence rate. PCR and CE-PCR were found to be superior to culture with presumptive biochemical identification and should be the preferred methods for the detection of A. actinomycetemcomitans in subgingival plaque.

Aggregatibacter actinomycetemcomitans↗
PubMed1994

Polymerase chain reaction for the identification of Porphyromonas gingivalis collagenase genes.

Porphyromonas gingivalis has been shown to exhibit genetic diversity possibly resulting in variation of virulence. In the present study a potential virulence factor was targeted for the detection of P. gingivalis. A 548 bp fragment of the collagenase gene (prtC) from Porphyromonas gingivalis ATCC 33277 was amplified by polymerase chain reaction (PCR) using oligonucleotides derived from the middle portion of prtC. From 16 of 21 clinical P. gingivalis strains, a PCR product of similar size to the prtC could be obtained. These 16 P. gingivalis strains were confirmed as positive for prtC using DNA hybridization with a digoxigenin-labeled prtC PCR product as a probe. In 12 of the 16 prtC positive strains, the restriction analysis of the PCR products revealed fragment patterns identical to the known sequence. In the other 4 prtC positive strains, 4 distinct patterns were found. Of these strains, nucleotide sequence analysis of a 400 bp PCR product stretch revealed 79.1%, 83.0%, 84.8 and 89.5% homology with the known nucleotide sequence for this specific region. Sequence analysis of the PCR products from the ATCC 33277 strain demonstrated 93.7% homology. The limit of detection for the PCR was about 100 organisms. None of the other 48 tested strains of 16 bacterial species derived from oral and extraoral infections yielded a PCR product. The PCR was also used for the detection of prtC sequences in dental plaque. Our data indicate that not all P. gingivalis strains have prtC. Nucleotide heterogeneity exists among P. gingivalis with prtC.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Proteins↗
PubMed1993

Effect of storage media on microleakage of five dentin bonding agents.

The objective of this study was to investigate the effect of different storage media on microleakage at the gingival margin of mixed Class V composite restorations. Human molars were either used immediately after extraction (control group) or after a 3-4 wk storage period in 1% chloramine, 70% ethanol, 10% formalin, or 0.1% thymol. Class V cavities with cervical margins in cementum or dentin were prepared and restored with a microfill composite using five different dentin bonding agents. After thermocycling (1440 x from 5 degrees C to 55 degrees C) and basic fuchsin staining, the depth of dye penetration at the gingival margins was determined and ranked on a scale of 0 to 4. Class V restorations in teeth stored in formalin showed significantly less microleakage (mean leakage score, MLS = 1.7) than restorations in freshly extracted teeth (control group; MLS = 3.1). Microleakage scores in teeth stored in chloramine (MLS = 2.7), ethanol (MLS = 3.0) or thymol (MLS = 3.2) were not significantly different from the microleakage scores in the control group. The improvement of in vitro efficacy of dentin bonding agents when using extracted teeth stored in formalin is probably a result of collagen cross-linking by formaldehyde. Since such an alteration of the dentin does not reflect the condition of the substrate in vivo, extracted teeth assigned for in vitro evaluation of dentin bonding agents should not be stored in formalin. In teeth stored in 1% chloramine, the sums of ranks and the rank orders of the dentin bonding agents were comparable to those in freshly extracted teeth.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1993

[The surface conditioning of pressed ceramics and its effect on the bond strength to composites].

After removal of the investment material, unpolished surfaces of pressed glass ceramics (Empress) are covered by a layer containing magnesium and phosphorus. This layer most likely results from the contact with the investment material during pressing. Following short-time conditioning with 5% HF-gel the superficial layer stays amorphous. After etching for 120 s most of the surface layer is removed revealing the fine grained etching pattern characteristic for this type of ceramics. Shear strength of composite luted to unetched pressed ceramic samples was rather low. After etching for 60 s bond strength was considerably higher, but only following 120 s of etching shear strength reached a level comparable to that of ground pressed samples and ground ingots after 60 s of etching. Since mechanical removal of the surface layer by grinding is not recommended, pressed glass ceramics should be etched for 120 s or longer to achieve an optimal bond strength to the luting composite.

Acid Etching, Dental↗
PubMed1992

Failure to detect any effect of amalgam restorations on peripheral blood lymphocyte populations.

Dental amalgam has been considered to have adverse side effects on the immune system. Reports have been contradictory, indicating both an increase and a decrease in peripheral blood lymphocyte counts associated with amalgam restorations. We investigated two groups of patients, one of which was treated with amalgam restorations for the first time. In the other group, all existing amalgam fillings were removed. Prior to and after treatment, we determined the absolute and relative numbers of granulocytes, lymphocytes, monocytes, T cells, B cells, cytotoxic T cells, helper T cells and natural killer cells. In addition, functional investigations of T cells were performed. We failed to find any effect of amalgam restorations on the immune system in terms of the parameters investigated.

Adolescent↗
PubMed1991

Shear bond strength to dentin by simulation of three-dimensional Class V cavity configuration.

The purpose of this study was to investigate the effect of composite polymerization contraction on early shear bond strength of conventional and new dentin adhesives to dentin. The dentin adhesives selected for this study, i.e., Bondlite, Gluma, Prisma Universalbond, Scotchbond LC, Scotchbond 2, and XR Bonding, were tested in combination with Silux and in combination with their respective composites. The composite was applied to the treated dentin surface in cylindrical brass moulds of 4 mm diameter and 3 mm length. The configuration of cylindrical butt-joint Class V cavities was simulated by the coating of the insides of the brass moulds with silane in order that a chemical bond to the composite could be established. The results showed that shear bond strength to dentin was higher for XR Bonding and Scotchbond 2 compared with conventional phosphate ester-based dentin adhesives and Gluma. When XR Bonding or Scotchbond 2 was used, the obstruction of polymerization contraction had no effect on the bond strength to dentin. In contrast, the dentin adhesion of Scotchbond LC/Silux, Prisma Universalbond/Prisma Microfine, Bondlite/Herculite, and Gluma/Lumifor was adversely affected by the reduction of the unbonded composite surfaces. However, this effect was not observed when Prisma Universalbond, Bondlite, and Gluma were tested in combination with Silux. It can therefore be concluded that the effect of polymerization contraction on the bond strength to dentin depends not only on the dentin adhesive but also on the type of composite used.

Adhesives↗
PubMed1991

[Effects of amalgam on cells of the immune system].

Dental amalgam has been considered to have adverse side effects on the immune system. There are controversial reports, which indicate an increase as well as a decrease in peripheral blood lymphocyte counts due to amalgam fillings. We investigated 2 groups of patients: one group was treated with amalgam restorations for the first time. In the other group all previous amalgam fillings were removed. Before and after treatment we determined the absolute and relative numbers of granulocytes, lymphocytes, monocytes, T cells, B cells, suppressor T cells, helper T cells and NK cells. In addition, functional investigations of T cells were performed. In conclusion, we could not find any effect of amalgam restorations on the immune system regarding the investigated parameters.

Adolescent↗
PubMed1991

[Mercury vapor emission from amalgam capsules during trituration and storage].

Inhalation of mercury vapor is a potential hazard when handling dental amalgam. To prove the safety of modern capsule systems, we tested 21 brands of dental amalgam. Mercury vapor emission was measured at different stages during handling: a) immediately after opening of a capsule package, b) cumulative emission over 24 h of storage of an open package, c) during trituration and d) for different methods of waste capsule treatment. Highly significant differences between capsule types were found for the measured parameters. Disposable capsules that could be reassembled showed the most favorable results.

Air Pollutants, Occupational↗
PubMed1991

[The effect of cavity finishing on the initial sealing capacity of amalgam fillings in vitro].

The effect of different cavity finishing methods on in-vitro microleakage of two amalgams (Amalcap non gamma 2 SAS, Tytin) was investigated by the dye penetration method. Amalcap non gamma 2 SAS demonstrated better sealing properties than Tytin. The highest degree of microleakage was observed when the cavities prepared with a diamond coated bur (mean particle size 80 microns) were left unfinished. The degree of marginal leakage in Class-I cavities was reduced by finishing their walls with tungsten carbide or diamond coated finishing burs. Cervical Class-II cavity walls finished with a tungsten carbide or a diamond coated finishing bur demonstrated lower marginal leakage than cervical walls finished with a gingival margin trimmer. Finishing of proximal Class-II cavity walls with tungsten carbide or diamond coated finishing burs followed by removal of the remaining enamel overhangs with a diamond coated file (Cavishape) resulted in a lower degree of dye penetration than finishing proximal walls with a proximal margin trimmer. The results indicate that Class-II cavities with minimal extension of the proximal walls can be effectively finished without using hand instruments.

Dental Amalgam↗
PubMed1990

[Ridge stabilization with adhesive inlays in MOD cavities].

The flexural rigidity of the buccal cusps of upper premolars was determined under a vertical load of 100 N by use of displacement transducers. The stiffness of the cusps was higher when the cavities were restored with cast gold onlays or with composite or ceramic inlays luted with composite resin. In most cases a decrease in cusp stiffness was observed after thermocycling of the teeth restored with composite or ceramic inlays. With amalgam restorations or cast gold inlays, the flexural rigidity of the cusps was not higher than that of the unrestored cavities.

Bicuspid↗
PubMed1990

[Shear bond strength between composite inlay and luting composite resin].

The shear bond strength between composite inlay materials and luting composite resins was measured under different storage conditions and using different finishing techniques. The initial shear bond strength was distinctly higher with light-cured composites subjected to secondary light and heat cure (56.7-81.1 MPa) than with a heat- and pressure-cured material, where appreciable bond strength was achieved only after sandblasting of the composite surface (18.8 MPa). In general, water storage of the samples for 30 days with intermittent thermocycling adversely affected the bond strength. The influence of secondary light and heat curing on the bond strength of primarily light-cured composites was highly dependent on the material used.

Composite Resins↗
PubMed1990

[Occlusal margin quality of Cerec-inlays several months after insertion].

The quality of the occlusal margins of 58 computer-machined ceramic inlays (Cerec) was examined by SEM. The adhesion of the luting composite to enamel and to the inlay appeared more of less stable. However, the wear of the composites was substantial and more pronounced in Brilliant and in Microfill pontic C than it was in Heliomolar.

Adult↗
PubMed1990

[Marginal seal of cervical composite inlays in vitro].

The presence of microleakage at the dentinal margins of conventional Class V restorations and direct composite inlays in combination with four dentin bonding agents was assessed by means of dye penetration. The use of dentinal adhesives with conventional one-step composite fillings failed to prevent marginal leakage. The dentin bonding agents used in this study were for more efficient when used with direct composite inlays. The resistance to thermal stress of these bonded Class V composite inlays was improved by application of a secondary light and heat cure, probably due to relaxation of residual material stress.

Acid Etching, Dental↗