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Biomedical subjects

R Frankenberger

Publications and source records attributed to R Frankenberger.

30 records · Page 2Linked to original sources

Direct posterior composite restorations with a new adhesive system: one-year results.

PURPOSE: Syntac Sprint is a new one-bottle adhesive based on the total-etch and total-bond technique. The aim of this study was to compare the new restorative system consisting of Syntac Sprint and the resin composite Tetric Ceram with the clinically proven combination of the dentin adhesive Syntac Classic and the resin composite Tetric. MATERIALS AND METHODS: In a controlled prospective clinical study, 47 cavities (36 premolars, 11 molars; 29 maxillary, 17 mandibular; 6 occlusal, 33 occluso-approximal, 7 MOD, 1 > 3 surfaces) in 33 patients (17 female, 16 male) were filled. Twenty-five fillings were placed with the combination Syntac Sprint/Tetric Ceram under total etching and total bonding conditions. In thirteen restorations, Syntac Sprint was precured prior to the application of the resin composite; in the other twelve cases, restoration and adhesive were cured simultaneously. The control group consisted of 22 cavities restored with Syntac Classic plus the composite Tetric. At baseline and after 6 and 12 months, two calibrated investigators examined the restorations with modified USPHS codes and criteria. RESULTS: The criteria marginal integrity and integrity of the tooth deteriorated significantly between the baseline and the 6- and 12-month investigations (Friedman 2-way ANOVA; p < 0.05). No differences were found in the criteria surface roughness, color matching, anatomic form, step formation, integrity of the filling, proximal contact, hypersensitivity, or satisfaction. After one year, all fillings were in good condition. There was no significant difference between the Syntac Sprint/Tetric Ceram and Syntac Classic/Tetric groups for any criterion (Kruskal-Wallis; p > 0.05). CONCLUSION: Within the limits of this study, Tetric Ceram fillings in combination with Syntac Sprint were clinically successful after one year.

Acrylates↗

Viscous glass-ionomer cements: a new alternative to amalgam in the primary dentition?

Glass-ionomer cements offer advantages in the treatment of the primary dentition. New, colored, highly viscous glass-ionomer cements hold the promise of better abrasion properties. Owing to their high viscosity, their handling characteristics are similar to those of amalgam. Examination of their properties demonstrated increased resistance to abrasion in comparison to amalgam, although no improvement in fatigue or flexural resistance was found. Clinical experience extending over 2.5 years confirmed these results.

Dental Amalgam↗

[Prenatal diagnosis in parents with a balanced structural chromosome aberration (author's transl)].

By means of 10 case reports, the significance of prenatal diagnosis and the risk for the progeny of parents with a balanced structural chromosomal aberration are demonstrated. The aberrations were ascertained through: a previous malformed child, previous miscarriages or stillbirths or through fetal cell analysis during prenatal diagnosis performed for independent reasons. Theoretical considerations concerning the estimates of risk figures in these families are presented and the currently available risk values which are the basis of the indication for prenatal diagnosis, given.

Adult↗

New chromosomal dysmorphic syndromes. 2. Trisomy 10p.

This is the report of a family in which a balanced translocation in the mother t(5;10)(p15;p13) led to an unbalanced chromosomal constitution in two children. It was identified by G-banding analysis as trisomy of the distal portion of the short arm of chromosome 10 (p13 leads to pter). Comparison with 15 previous reports of trisomy 10p confirms the existence of a characteristic dysmorphic syndrome.

Abnormalities, Multiple↗

[The chromosome bands. Significance for clinical and cytogenetic research (author's transl)].

The methods of performing chromosomal investigations have been fundamentally changed in the last few years through the discovery of differential staining methods. While only a rough classification of the chromosomes into single groups could be carried out earlier, it is now possible to identify every individual pair of chromosomes on the basis of a typical pattern of bands. By means of these banding techniques smaller chromosomal variations can be recognized which were overlooked earlier and which have led to the delineation of new chromosomal malformation syndromes. In the present work, the modern methods of chromosome analysis are reviewed. Examples from clinical diagnosis show the necessity of using these techniques.

Abnormalities, Multiple↗

Dentin bond strength and marginal adaptation: direct composite resins vs ceramic inlays.

The aim of this in vitro study was to compare the dentin bond strength and marginal adaptation of directly and indirectly inserted restorations. A conically modified push-out test was designed to consider polymerization shrinkage and facilitate inlay placement. A total of 260 cavities were prepared into disks of freshly extracted human third molars and filled with direct composite resins or with adhesively luted ceramic inlays. Dentin adhesives of the third--(with self-etching primer: ART Bond, Syntac Classic), fourth--(with total etching: Scotchbond Multi-Purpose Plus), and fifth-generation (one-bottle adhesives: Syntac Single Component, Prime & Bond 2.1) were used in combination with one hybrid composite (Tetric) or luting composite (Variolink Low). Control groups did not use an adhesive. Polymerization of the bonding agent was carried out prior to insertion of the filling/inlay or afterwards simultaneously with the composite/luting composite. The thickness of the adhesive layer and luting composite was recorded, and after 7 days of storage and 24 hours of thermocycling (1150 cycles) replicas were made and extrusion testing performed. Fracture modes were determined and replicas were examined regarding marginal adaptation using SEM (X200 magnification). Precuring of the bonding resin increased dentin bond strength independent of the material combination or insertion mode (P < 0.05). In general, third- and fourth-generation dentin adhesives produced better results in bond strength and marginal adaptation than one-bottle systems (P < 0.05). In the third generation, ART Bond achieved significantly higher push-out values than Syntac (P < 0.05), but no better marginal adaptation. Cohesive fractures within the dentin were only observed in the inlay groups with precured resin. Precuring of the bonding resin is an important factor for both direct and indirect restorations. Nevertheless, precuring of the bonding resin prior to insertion of adhesive inlays cannot be recommended clinically, because the 120-micron luting spaces were too large. In simulated cavities, direct composite fillings with precuring achieved bond strengths similar to inlays without precuring. One-bottle adhesive systems performed poorly compared with multi-step adhesives of the third and fourth generation.

Analysis of Variance↗

Long-term effect of dentin primers on enamel bond strength and marginal adaptation.

Contamination of etched enamel with dentin adhesive systems is unavoidable in clinical situations. The aim of this in vitro study was to evaluate the long-term effect of dentin adhesives and application technique on resin composite bond strength and marginal adaptation to enamel. Six hundred freshly extracted mandibular bovine incisors were used. Three hundred teeth were flat ground, and the enamel was etched for 30 seconds with 32% phosphoric acid. The etched surface was treated by different dentin adhesive systems with and without intensive rubbing by use of application brushes. As a control, only the enamel adhesive resin was applied and air thinned. Furthermore, contamination with saliva was performed after the etching process. Etched and silanated CEREC blocks were bonded onto the enamel specimens with different adhesive resins and stored for 1 and 365 days (37 degrees C, aqua dest). After storage, the specimens were thermocycled for 24 hours (1150 cycles between 5 degrees C and 55 degrees C), and subjected to shear bond testing. Three hundred box-shaped cavities were prepared on buccal surfaces of the incisors and filled with one resin composite using the same pretreatment modes as in the shear bond test groups. After 1 and 365 days of storage, a margin analysis was performed using a SEM (X200 magnification). Dentin adhesive systems did not show an adverse effect on long-term enamel bond strength and marginal adaptation. Rubbing application of the primers decreased the bond strength by values of approximately 20% after 24 hours and approximately 40% after 1 year of storage. Marginal adaptation showed 94-98% gap-free margins in the control and dentin adhesive system-only groups; however, after rubbing of primers, the proportion of gap-free margins decreased significantly to 85-88%. The lowest bond strength (8-10 MPa) and margin quality (49-69% gap-free margins) were recorded for the groups with saliva contamination.

Animals↗

Dentin bond strength and marginal adaption after NaOCl pre-treatment.

The aim of this in vitro study was to compare the dentin bond strength and marginal adaptation of direct composite resins with and without additional NaOCl treatment after the etching process. A total of 150 cavities were prepared into disks of freshly extracted human third molars and filled with direct composite resins. Dentin adhesives of the fourth (with total etching: Scotchbond Multi-Purpose Plus, EBS, and Solid Bond), and fifth generation (one-bottle adhesives: Prime&Bond 2.1, Syntac Sprint) were used in combination with corresponding composite resin materials. Dentin disks without cavity preparation treatment served as controls. After 24 hours of storage and 24 hours of thermocycling (1150 cycles), replicas were made and push-out testing was performed. Replicas were examined regarding marginal adaptation using SEM (X200 magnification). In general, fourth-generation dentin adhesives produced better results in bond strength and marginal adaptation than fifth-generation one-bottle systems (P < 0.05). Within the fourth generation, Scotchbond Multi-Purpose Plus and EBS achieved significantly higher push-out values and percentages of gap-free margins than Solid Bond (P < 0.05). After hypochlorite treatment, dentin bond strength (-25%) and marginal adaptation (-30%) decreased significantly (P < 0.05) in all groups.

Acetone↗

Repair strength of etched vs silica-coated metal-ceramic and all-ceramic restorations.

The purpose of this in vitro study was to examine shear bond strengths of composite resin to metal-exposed porcelain-fused-to-metal (PFM) and all-ceramic restorations after silica coating or etching with 5% hydrofluoric acid (HF). Specimens were fabricated for each of the following groups: two all-ceramic materials [a feldspathic porcelain (Vita Mark II) and a leucite-reinforced glass-ceramic (IPS Empress)], and one noble metal-ceramic (Orplid Keramik I alloy; Vita VMK 68 N felspathic veneer ceramic). These groups were repaired with resin composites after different pretreatment methods. In one metal-ceramic subgroup the surface exhibited a 50% metal and 50% ceramic exposure. In the silica-coating groups, the specimen surfaces were air abraded with silica acid-modified Al2O3 (CoJet Sand) and treated corresponding to the porcelain repair with resin composite. For control groups, the surfaces were etched with 5% HF for 60 seconds and treated in the same way as the silica-coated groups. After 24 hours of storage (distilled water, 37 degrees C) and an additional 24 hours of thermocycling (1150 x 5 degrees C/55 degrees C) the specimens were debonded using a shear bond strength test (n = 15). In all groups the silica coat repair achieved equal or significantly higher bond strengths than did the etching technique (p < 0.05, Mann-Whitney U test). In the metal-exposed group, the mean bond strength increased from 7.3 MPa to 16.3 MPa following the silica-coat repair. Results indicated that silica coating represents a suitable treatment for the intraoral repair of the materials tested in the present study.

Acid Etching, Dental↗

Technique sensitivity of dentin bonding: effect of application mistakes on bond strength and marginal adaptation.

This in vitro study evaluated dentin bond strength and marginal adaptation of direct resin composites according to the manufacturers' instructions and with simulated application errors. One hundred and forty cavities were prepared into disks of freshly extracted human third molars and filled with one resin composite. Dentin adhesives of the third (with self-etching primer: Syntac Classic), fourth (with total etching: Scotchbond Multi-Purpose Plus) and fifth generation (one-bottle adhesive: Prime&Bond 2.1) were used for bonding. Simulated application mistakes were as follows: 1) prolonged etching; 2) excessive drying after conditioning; 3) drying primers immediately after application and 4) drying primers excessively. After 21 days of storage and 24 hours thermocycling (1150 cycles), replicas were made and push-out testing was performed. Replicas were examined for marginal adaptation using SEM (X200 magnification). Compared with values of the control groups, application errors resulted in dramatically decreased bond strengths and reduced percentages of gap-free margins for all products tested (p < 0.05). Excessive drying after conditioning exhibited significantly less effect for the third generation adhesive than for products requiring total etching/wet bonding.

Acid Etching, Dental↗

Leucite-reinforced glass ceramic inlays and onlays after six years: clinical behavior.

Ceramic inlays are an esthetic substitute for large amalgam and other metallic restorations. This controlled clinical study evaluated the performance of IPS Empress inlays and onlays with cuspal replacements and proximal margins below the cementoenamel junction over six years of clinical service. Six dentists placed 96 ceramic restorations in 34 patients. Luting was accomplished using the enamel-etch-technique, a dentin bonding system (Syntac Classic) and four different composite systems. The restorations were assessed by two calibrated investigators using modified USPHS criteria at baseline (96 restorations), one (96), two (95), four (89) and six years (67). Seven of the 96 restorations investigated had to be replaced (failure rate 7%; Kaplan-Meier): Five inlays suffered cohesive bulk fractures and two teeth required endodontic treatment. After six years of clinical service, significant deterioration (Friedman 2-way ANOVA; p < 0.05) was found for marginal adaptation of the remaining restorations. Ninety-four percent of the surviving restorations exhibited marginal deficiencies, independent of the luting composite. Neither the absence of enamel margins, nor cuspal replacement significantly affected the quality of the restorations.

Acid Etching, Dental↗

Leucite-reinforced glass ceramic inlays after six years: wear of luting composites.

Wear of luting composites is still an unsolved problem with adhesive inlays. However, only limited clinical research has been conducted regarding this phenomenon. This study evaluated the substance loss within the luting gap over a six-year period in vivo. In the course of a controlled prospective clinical study, 16 patients received 39 Class-II IPS Empress inlays. Variolink Low (Vivadent; n = 18) was used as conventional low-viscosity luting composite, the hybrid-type restorative resin composite Tetric (n = 21; Vivadent) was applied according to the ultrasonic insertion technique. The restorations were clinically assessed after 6, 12, 24, 36, 48 and 72 months and replicas were made. The contact-free occlusal areas of the replicas were scanned by use of a computer-controlled profilometer (Perthen S3P), the analysis of the data was computed using a newly developed software (Xpert for Windows 95) and statistically analyzed with non-parametric tests. After six months all restorations exhibited marginal ditching. The percentage of detectable luting gap abrasion increased between each recall appointment (32% after six months, 48% after 12 months, 46% after 24 months, 55% after 36 months, 59% after 48 months and 65% after 72 months). Except for the 48-months results, no significant difference between the materials used for luting was evident (p > 0.05). Between the width and the depth of the luting space a linear regression was computed. The quantitative evaluation clearly demonstrated that hopes of relevantly reduced wear of luting composites were not confirmed when using the higher filled luting material.

Adult↗