Biomedical subjects

T Attin

Publications and source records attributed to T Attin.

At least 55 records · Page 3Linked to original sources

PubMed1998

Clinical evaluation of a hybrid composite and a polyacid-modified composite resin in Class-II restorations in deciduous molars.

The aim of this prospective study, conducted in a dental practice was to evaluate the success rate of a hybrid composite material (TPH-Spectrum; Dentsply DeTrey, Konstanz, Germany) and a polyacid-modified composite resin (Compoglass; Vivadent, Schaan, Liechtenstein) in Class II restorations in primary molars after 1 year. A total of 190 restorations (96 with TPH-Spectrum and 94 with Compoglass) were inserted in 52 children. TPH-Spectrum was applied using the total etching technique, whereas Compoglass was inserted without acid etching prior to application of the bonding adhesive. The restorations were assessed according to the Ryge criteria, directly after placement and after 1 year. After 12 months, 6.4% of the Compoglass and 3.1% of the TPH-Spectrum restorations were clinically unacceptable and had to be renewed. The fillings with Compoglass revealed a tendency to lower evaluation scores with respect to color matching, cavosurface discoloration, anatomic form, margin integrity and caries assessment than the restorations with TPH-Spectrum. However, these differences were statistically not significant. The results of the present investigation show that, at least for a period of 1 year, both the hybrid composite TPH-Spectrum and the polyacid-modified composite resin Compoglass are suitable materials for restoration of deciduous molars. However, owing to the fewer treatment steps required for application of a polyacid-modified composite resin, this type of material may be more favorable for restoring primary molars.

Chi-Square Distribution↗

PubMed1998

Toothbrushing abrasion of polyacid-modified composites in neutral and acidic buffer solutions.

STATEMENT OF PROBLEM: Polyacid-modified composites are recommended for use in lesions that are subjected to toothbrushing abrasion and acidic challenges, such as cervical lesions. There is little information whether these materials are able to withstand degradation due to erosive attacks and toothbrushing abrasion. PURPOSE: This study evaluated the resistance of polyacid-modified composites against toothbrushing abrasion under acidic and neutral conditions. METHODS: Forty specimens fabricated of each of two polyacid-modified composites (Dyract, Compoglass) were investigated. For each composite group, 20 specimens were placed in a neutral solution (pH: 6.8) and 20 specimens were placed in an acidic solution (pH: 3.0) for 24 hours. All specimens were brushed in an automatic toothbrushing machine, then subjected to storage in the respective buffer solution (8 hours), followed by brushing three times. Abrasion was determined profilometrically. RESULTS: For both materials, abrasion in the acidic environment was significantly higher compared with neutral conditions. Thus, Compoglass composite demonstrated a lower abrasion resistance than Dyract composite. CONCLUSION: The abrasion resistance of the investigated materials was reduced under acidic conditions.

Acids↗

PubMed1998

Evaluation of the apical seal of root canal fillings with different methods.

The purpose of the study was to compare dye penetration methods conducted passively, under negative pressure, or under high pressure conditions. Ninety human maxillary incisors were instrumented and obturated with either the lateral condensation or single cone technique. India ink was used as a dye for passive and negative pressure (60 Torr) penetration methods. For dye penetration under high pressure conditions (200 MPa), a colored epoxy resin was used. Apical leakage was linearly measured evaluating both the root surface that showed the highest degree of penetration and all four surfaces of each root. The results revealed no significant difference between passive and negative pressure penetration methods. The amount of apical leakage obtained using dye penetration under high pressure conditions was significantly lower. Lateral condensation and single cone techniques yielded similar sealing abilities. It is concluded that there is no need to use negative pressure for evaluating the sealing ability of root canal fillings in vitro.

Carbon↗

PubMed1998

Brushing abrasion of eroded dentin after application of sodium fluoride solutions.

The aim of the present in vitro study was to evaluate the influence of sodium fluoride solutions on brushing abrasion of eroded dentin. Dentin specimens were prepared from 60 bovine incisors. The specimens were embedded in acrylic resin, ground flat, polished and subsequently covered with tape exposing an area of 1.8 mm x 10.0 mm in the center of the exposed dentin. The samples were alternatingly stored in a demineralizing solution (5 min) and a remineralizing solution (1 min) for 5 times. The erosive soft drink Sprite light(R) served as a demineralizing solution and artificial saliva was used as a remineralizing solution. Prior to storage in artificial saliva 15 specimens were each treated for 1 min with 250 and 2,000 ppm fluoride solution, respectively. Fifteen specimens were treated with distilled water instead of the fluoride solution (= eroded controls). The remaining samples were neither eroded with the soft drink nor fluoridated (= uneroded controls). After each immersion in artificial saliva the specimens were submitted to abrasion in a toothbrushing machine. After 5 demineralization-remineralization brushing cycles the total amount of tooth wear due to erosion and subsequent abrasion was profilometrically evaluated. Statistical analysis revealed the significantly lowest wear in the uneroded controls and the highest amount of abrasion in the eroded controls. Application of the fluoride solutions increased the wear resistance of the eroded dentin specimens, showing significantly better protection by the high-concentration compared to the low-concentration solution. The susceptibility to abrasion of the eroded dentin specimens treated with the high-concentration fluoride solution did not differ significantly from the uneroded dentin samples. It is concluded that application of 2,000 ppm sodium fluoride solutions immediately before toothbrushing significantly reduces abrasion of eroded dentin in vitro.

Animals↗

PubMed1997

In vivo study on the effectiveness of a lacquer containing CaF2/NaF in treating dentine hypersensitivity.

The purpose of this double-blind study was to evaluate the effectiveness of a commercially available fluoride lacquer (Bifluorid 12) containing CaF2 (6%) and NaF (6%) in reducing dentine hypersensitivity. A fluoride lacquer containing only NaF (6%) served as a control. Twenty-five adult patients complaining about at least two hypersensitive teeth participated in this study. In each patient and at each appointment, one tooth was treated with Bifluorid 12, while the other was treated with the control substance. Sensitivity levels were determined before and after the application of each lacquer at baseline as well as at 1, 2 and 3 weeks after the start of study. The final evaluation of hypersensitivity was performed at 4 weeks, and follow-ups were undertaken at 6 and 12 months. A reproducible air blast stimulus and a visual analogue scale were used for evaluation. Results demonstrated a distinct reduction of hypersensitivity after 1, 2 and 3 weeks in the Bifluorid 12 group. Initially, no obvious effects could be observed in the control group. However, a clear alleviation could be observed after 2 and 3 weeks with the control. After 4 weeks, the overall sensitivity scores were comparably low, without any significant differences between the two fluoride lacquers. In both groups, the effects of treatment were seen over the 12-month observation period. Bifluorid 12 was considered at least comparable to the control. It is concluded from this study that Bifluorid 12 is effective in the initial reduction of dentine hypersensitivity. The combination of CaF2/NaF can be recommended for clinical use.

Adult↗

PubMed1997

Fluoride uptake in dentin with and without simulating dentinal fluid flow.

The aim of the present study was to compare fluoride uptake of dentin with and without simulating dentinal fluid flow. Eighty-five dentinal discs were prepared from retained human molars. Seventeen discs were used to assess baseline fluoride content (controls). Sixty-eight discs were evenly distributed among two experimental groups and were fixed for 24 h in a two-chamber device allowing for simulating dentinal fluid flow. Thirty-four samples were treated with dentifrice slurry containing a low fluoride concentration (Elmex, dilution 1:5); the remaining discs were treated with a solution of a high fluoride concentration (Elmex Fluid). For the perfused group, each of the 17 discs of the high and low concentration fluoride groups were constantly perfused during the experiment. The remaining fluoridated specimens were not perfused. All specimens were assayed for KOH-soluble fluoride and structurally bound fluoride. Structurally bound fluoride was determined in three successive layers of 20 microns each. Uptake of KOH-soluble fluoride was significantly higher in the specimens fluoridated with Elmex Fluid compared to the samples treated with the dentifrice slurry. The uptake of KOH-soluble fluoride was not influenced by perfusion of the dentinal discs. However, perfusion resulted in lower acquisition of structurally bound fluoride in the samples treated with the dentifrice slurry. After application of Elmex Fluid, no significant difference was found in the amount of structurally bound fluoride between the perfused specimens and non-perfused samples. It is suggested that further studies on fluoride uptake in dentin should use a model simulating outward dentinal fluid flow.

Analysis of Variance↗

PubMed1997

Correlation of microhardness and wear in differently eroded bovine dental enamel.

The purpose of the study was to compare the microhardness data of differently eroded enamel surfaces with the wear caused by toothbrushing. Sixty bovine enamel specimens were polished and prepared for microhardness determination. The polished surfaces were covered with tape except for a 1.3 x 10.0 mm window. Fifteen specimens each were stored in an erosive beverage (Sprite Light) for either 1, 5 or 15 min. Each specimen was immersed in 10 ml of the beverage. The remaining 15 specimens were not eroded. Interferometrical analysis revealed that substance loss after 15 min of erosion was negligibly low (about 75 mm). In all specimens Vickers microhardness determinations were conducted on eroded (= final hardness) and non-eroded (= initial hardness) enamel surfaces. The specimens were subsequently submitted to toothbrushing abrasion using a slurry consisting of 1 g non-fluoridated dentifrice in 5 ml artificial saliva. The total amount of tooth wear due to erosion and subsequent abrasion was profilometrically evaluated. Statistical analysis revealed a significant decrease in hardness and a significant increase in wear with increasing time of storage in the erosive beverage. Overall regression analysis yielded a statistically significant correlation between both initial and final hardness and the amount of tooth wear. The correlation of abrasion and final hardness could be described by a quadratic mathematical function. It is concluded that the susceptibility of eroded enamel to toothbrushing abrasion can be correlated with Vickers microhardness values, thereby suggesting an overproportionate increase of abrasion with decreasing hardness values.

Animals↗

PubMed1997

Effect of fluoride treatment on remineralization of bleached enamel.

The objective of the study was to evaluate the remineralizing capacity of different fluoride treatments on dental enamel bleached with carbamide peroxide (Opalescence). Sixty bovine enamel slabs were subjected to four cycles comprising bleaching (12 h) and remineralization in artificial saliva (8 h). The samples were evenly distributed among four groups (A-D). During the first hour of the remineralization period the specimens in Group A were covered with a fluoride varnish (Duraphat; 2.23% F-). In group B the enamel slabs were stored in a fluoride solution (0.2% F- as NaF) for 1 min prior to remineralization. Group C did not receive a fluoride treatment, and group D (control) was stored in distilled water instead of bleaching. Microhardness (VHN) was evaluated before the experiments and after the second and fourth cycle, respectively. Final hardness was calculated as percentage of the initial hardness. Analysis of variance was applied to the data followed by pairwise comparisons with corrected level of significance (P < 0.01). Hardness decreased significantly in groups A-C compared to the control group (D). The bleached and unfluoridated specimens (group C) showed a significantly higher hardness loss compared to the fluoridated specimens, whereas no significant difference was observed between the two fluoridated groups. It is concluded that remineralization of bleached enamel is improved by application of highly concentrated fluorides.

Analysis of Variance↗

PubMed1996

Influence of enamel conditioning on bond strength of resin-modified glass ionomer restorative materials and polyacid-modified composites.

This study evaluated enamel bond strength of restorative materials containing both glass ionomer and composite components. Three resin-modified glass ionomer restorative materials (Fuji II LC, Vitremer, Photac-Fil), three polyacid-modified composites (VariGlass VLC, Dyract, Ionosit Fil), a hybrid composite (blend-a-lux) and a chemical-cured glass-ionomer cement (ChemFil Superior) were tested for enamel tensile bond strength with and without conditioning of the tooth surfaces. Tensile bond strength was determined for five specimens each of conditioned and unconditioned bovine teeth. Specimen conditioning was performed as recommended by the manufacturers. The tensile bond strength was tested with a universal testing machine. Except for the enamel bond strength of ChemFil Superior, all materials showed greater adhesion to conditioned tooth surfaces than to unconditioned specimens. Enamel bond strengths of the polyacid-modified composites applied after a phosphoric acid etching technique (Ionosit Fit, Dyract, VariGlass) were greater compared with the materials applied after surface conditioning with polyacrylic acid-containing agents. No significant difference was observed between the hybrid composite and the tested materials attached with the phosphoric acid etching technique. To improve adhesion of the tested materials to enamel, following the manufacturer's instructions about tooth surface conditioning is recommended. Superior bond strength to enamel was obtained for polyacid-modified composites, which are attached with the phosphoric acid etching technique and thereby resemble the adhesion patterns of composites.

Acid Etching, Dental↗

PubMed1996

Properties of resin-modified glass-ionomer restorative materials and two polyacid-modified resin composite materials.

The objective of the study was to evaluate the physical properties of four resin-modified glass-ionomer cements (Fuji II LC, Ionosit Fil, Vitremer, Photac-Fil) and two polyacid-modified resin composite materials (Dyract and Variglass VLC)). They were compared with a hybrid resin composite (blend-a-lux) and a chemically cured glass-ionomer cement (ChemFil Superior). The compressive strength, flexural strength, modulus of elasticity, and surface microhardness of the resin-modified glass-ionomer materials and the polyacid-modified resin-composite materials were inferior to those of the hybrid resin composite and similar to those of the conventional glass-ionomer cement. The hybrid resin composite exhibited the lowest resistance to wear caused by brushing. Some of the materials showed a marked decrease in hardness at depths exceeding 2.0 mm. Generally, the strength properties of the tested resin-modified glass-ionomer materials and the polyacid-modified resin composite materials were inferior to those of the hybrid resin composite.

Chemical Phenomena↗

PubMed1996

Salivary fluoride content after toothbrushing with a sodium fluoride and an amine fluoride dentifrice followed by different mouthrinsing procedures.

The aim of the present study was to determine the salivary fluoride content after toothbrushing with a sodium fluoride and amine fluoride dentifrice followed by two different mouthrinsing procedures. Twenty-four dental students took part in this six-treatment, six-period study with a cross-over design. They brushed their teeth with an amine fluoride, a sodium fluoride, and a non-fluoridated dentifrice. After toothbrushing the subjects spat out the saliva/dentifrice slurry and underwent one of the following procedures: 1) mouthrinsing with 20 ml distilled water; 2) no mouthrinsing after spitting out. Whole saliva samples were collected before (baseline), 10 and 90 min after toothbrushing and mouthrinsing, respectively. Fluoride analysis was performed with a fluoride-sensitive electrode. Both dentifrices caused an elevated fluoride level in saliva after brushing. Use of the amine fluoride dentifrice resulted in higher salivary fluoride contents compared to the sodium fluoride toothpaste. However, this difference was statistically significant only 90 min after toothbrushing when preceded by mouthrinsing after brushing. Mouthrinsing with water after brushing led to significantly lower fluoride levels compared to the non-rinsing technique 10 min after brushing. Mouthrinsing after toothbrushing with fluoride dentifrices reduces the salivary fluoride concentration of both an amine and a sodium fluoride dentifrice.

Adult↗

PubMed1996

Influence of dentin conditioning on bond strength of light-cured ionomer restorative materials and polyacid-modified composite resins.

The purpose of the study was to evaluate the dentin bond strength of restorative materials containing both glass ionomer and composite resin components. Three resin-modified glass ionomer restorative materials (Fuji II LC, Photac-Fil, Vitremer), three polyacid-modified composite resins (Dyract, Ionosit Fil, VariGlass VLC), a hybrid composite (blend-a-lux) and a chemical-cured glass ionomer cement (ChemFil Superior) were investigated for dentin tensile bond strength with and without conditioning of the tooth surfaces. For each material, tensile bond strength was determined using five conditioned and five unconditioned bovine tooth specimens. Conditioning of the specimens was performed according to the manufacturers' instructions. The tensile bond strength was tested with a universal testing machine. Statistical analysis was performed with analysis of variance, the Scheffe's-test and the Student's t-test. All materials showed higher adhesion to conditioned dentin than to unconditioned specimens. Except for Photac-Fil, the bond strength to conditioned dentin of all resin-modified glass ionomer restorative materials and polyacid-modified composite resins was higher as compared to the chemical-cured glass ionomer and the hybrid composite. However, these differences were not statistically significant. All polyacid-modified composite resins resulted in higher bond strengths to conditioned dentin as compared to the resin-modified glass ionomer restorative materials. These differences were statistically significant only for VariGlass VLC as compared to Photac-Fil. In order to improve adhesion of the tested materials to dentin it is highly recommended to follow the manufacturers' instructions concerning dentin conditioning.

Acrylic Resins↗

PubMed1995

Fluoride retention of incipient enamel lesions after treatment with a calcium fluoride varnish in vivo.

The aim was to determine the fluoride retention in plaque-covered and clean incipient enamel lesions after topical application of a CaF2/NaF varnish (Bifluorid 12). In 50 specimens of bovine enamel an incipient lesion was produced with acidic hydroxyethylcellulose (pH 4.8; 72 h). 40 specimens were fluoride varnished; the 10 remaining specimens were used for measuring baseline fluoride content. Each six of the fluoridated specimens were recessed in the buccal aspects of an intraoral appliance worn for 5 days. During the experimental period one side of the appliance was kept clean, and plaque growth was allowed on the other. KOH-soluble and structurally bound fluoride were determined immediately, 1 day, 3 days and 5 days after fluoridation, and compared with the baseline fluoride content of the enamel. Immediately after fluoridation, a considerable amount of KOH-soluble fluoride was bound, but after 5 days 80% had been lost. Simultaneously a significant increase of non-KOH-soluble or structurally bound fluoride was detected in both plaque-covered and clean enamel. It is evident that this CaF2/NaF varnish deposits more KOH-soluble fluoride on the surface of demineralized enamel than other varnishes, but after 5 days fluoride retention is similar to that from other varnishes.

Analysis of Variance↗

PubMed1995

Curing shrinkage and volumetric changes of resin-modified glass ionomer restorative materials.

OBJECTIVES: The objective of the study was to evaluate initial curing shrinkage and volumetric change during water storage of six resin-modified glass ionomer cements (Dyract, DeTrey Dentsply; Fuji II LC, GC Dental Int.; Ionosit Fil, DMG; VariGlass VLC, DeTrey Dentsply; Vitremer, 3M Dental Products; Photac-Fil, ESPE), a hybrid composite (blend-a-lux, Blendax) and a chemical-cured glass ionomer cement (ChemFil Superior, DeTrey Dentsply). METHODS: The curing shrinkage was determined 5 min and 24 h after polymerization and mixing, respectively. Volumetric changes were examined after 14 d and 28 d water storage. Curing shrinkage and volumetric changes were evaluated using the hydrostatic principle. In addition, the total water content of the materials was measured after 28 d water storage. RESULTS: Curing shrinkage of most of the resin-modified glass ionomers was greater than the hybrid composite and the chemical-cured glass ionomer cement. After a 28 d water storage, the resin-modified glass ionomers showed volumetric expansion and the chemical-cured glass ionomer showed volumetric loss. All of the examined glass ionomer materials had a higher total water content than the composite. SIGNIFICANCE. The large curing shrinkage of the resin-modified glass ionomer materials measured in this in vitro study could affect the marginal integrity of glass ionomer restorations.

Acrylic Resins↗

PubMed1995

Plaque surface area after rinsing with a low-level fluoride-containing Darjeeling tea.

Plaque surface area after rinsing with a tea, containing low levels of fluoride, was evaluated in 30 human volunteers with a single-blind, one-operator, three-period, three-treatment cross-over study. The mouthwashes employed were: (1) tea (Darjeeling first flush:< 0.2 ppm F-), (2) Meridol(R), (3) control (tap water:< 0.2 ppm F-). During the experiment the participants refrained from oral hygiene procedures and rinsed their mouth three times a day after each meal with 20 ml of the respective rinse. After 3 d standardized photographs were taken of the upper canines and premolars and the plaque areas were measured planimetrically. Statistical analysis showed a marked decrease in plaque surface area after rinsing with Meridol, whereas no difference in plaque surface area was observed after mouthrinsing with tea and tap water, respectively.

Adolescent↗

PubMed1995

[Mercury release from separated amalgam after the use of different disinfectants].

Set amalgam, annealed for twelve days, was cut with water cooling and sucked into eight dental units (Systematica 1062 T), equipped with an amalgam separator (Multisystem Type 1). Disinfection of the suction devices was performed with seven commonly used disinfectants according to the manufacturer's guidelines. Rinsing with water served as a control in the last experimental series. The waste water was collected at the beginning of the experiments and after disinfection. Repeating the experiments for seven times resulted in 112 specimens that were analyzed by atomic absorption spectrophotometry. The use of Green & Clean M2 and S & M matic resulted in very low releases of mercury. Disinfection with Alprojet D and Alprojet DD M2 was comparable with the control group. The release of mercury was significantly increased, if compared to Green & Clean and S & M matic (p < or = 0.05). The use of Orotol Ultra, Aseptoclean 2, and Tiutol resulted in significantly higher releases of mercury, if compared to all other disinfectants (p < or = 0.05). Disinfectants containing oxidizing agents provoke an increasing release of mercury, thus accumulating the amounts of mercury in the general environment.

Analysis of Variance↗

PubMed1995

Endodontic therapy in a postirradiated child: review of the literature and report of a case.

Exodontia of extremely carious teeth leads to a significant risk of osteoradionecrosis in patients who have undergone radiotherapy. In these patients, endodontic treatment could be an alternative. Successful root canal therapy in a girl who had been irradiated for head and neck neoplasms is reported. The results indicated that use of calcium hydroxide to obturate the root canals is a viable method of postirradiation endodontics in primary teeth.

Animals↗

PubMed1993

[Does the application of a fluoride lacquer modify the de- and remineralization of initial carious lesions in vitro?].

Bovine enamel specimens with artificial initial lesions were fluoridated with a fluoride lacquer (Duraphat) for 6 hours. Subsequently artificial plaque (Streptococcus mutans, FA1) was grown on the enamel blocks in an artificial mouth. During the experimental period (23 days) the specimens were continuously rinsed with synthetic saliva and with sucrose twice daily. Nonfluoridated specimens served as controls. At the end of the experiment microhardness was evaluated in three levels parallel to the enamel surface. In addition, the concentration of KOH-soluble and structurally bound fluoride was determined. In the fluoridated specimens microhardness increased in levels near the surface of the lesion, but decreased in the next two lower levels. However, in the nonfluoridated enamel specimens microhardness decreased in all three levels and was more pronounced compared to the fluoridated specimens. At the end of the experiment no KOH-soluble fluoride could be determined on the surfaces of the artificial lesion. In contrast, structurally bound fluoride was significantly increased in the fluoridated specimens. A single application of the fluoride lacquer on initial enamel lesions resulted in remineralization of the outer enamel layers even under persisting cariogenic conditions. However, lesion progression could not be inhibited totally.

Animals↗