Biomedical subjects

Fabio Bertini

Publications and source records attributed to Fabio Bertini.

4 recordsLinked to original sources

PubMed2006

Effect of operator skill in relation to microleakage of total-etch and self-etch bonding systems.

OBJECTIVES: To evaluate the influence of operator skill on microleakage in class V restorations using two-step bonding systems. METHODS: Two standardized box cavities were made on the buccal and lingual surfaces of 54 human bicuspid teeth, with the cervical margin in dentin. The teeth were randomly assigned to two groups according to the operator's skill. Students group: undergraduate students. Expert group: a dentist with 20 years of clinical experience in dental adhesion. The buccal cavities of each tooth were treated with Prime&Bond NT (two-step total-etch system); the lingual cavities were treated with AdheSE (two-step self-etch system). All cavities were restored by a single calibrated operator with one bulk increment of resin composite (InTens; Ivoclar Vivadent). Specimens were thermocycled, immersed in 2% methylene blue and sectioned in a bucco-lingual plane in the middle of the restorations. They were then examined under a stereomicroscope and scored according to microleakage by two operators who were blind to the specimen preparation. The data was subjected to a multilevel statistical model. RESULTS: The microleakage resulting from the self-etch adhesive was similar in the student and in the expert groups. On the other hand, the total-etch adhesive microleakage within the expert group resulted lower than that within the student group. However, the interaction term skill x adhesive resulted statistically significant at the dentin margin (p=0.0474) but not at the enamel margin (p=0.1267). CONCLUSION: While the total-etch adhesive used in this study showed to be skill-sensitive, the self-etch one proved to be less skill-sensitive in obtaining a reliable seal with dentin.

Acid Etching, Dental↗

PubMed2005

Morphological and functional rehabilitation of severely infra-occluded primary molars in the presence of aplasia of the permanent premolar: a clinical report.

This clinical report describes the fixed prosthodontic rehabilitation of an infra-occluded primary molar. Diagnostic considerations included the patient's age, occlusal status, condition of the infra-occluded tooth including the degree of infra-occlusion and root resorption, as well as adjacent alveolar bone levels. Due to the patient's young age, an invasive prosthetic approach was delayed in favor of an onlay restoration, which represented a more rapid and conservative therapeutic choice. The treatment involved the design and fabrication of a composite onlay on the deciduous molar using a ceramic optimized polymer on a fiber-reinforced composite framework. Three years later, intraoral radiography showed satisfactory marginal adaptation. No change was observed in periodontal tissues.

Adolescent↗

PubMed2004

Translucent fiber post cementation using a light-curing adhesive/composite system: SEM analysis and pull-out test.

OBJECTIVES: The performance of both light-curing and dual-cured adhesive/luting systems (as control), when used in combination with translucent fibre posts, was evaluated by means of pull-out test and scanning electron microscopy (SEM ) observation. METHODS: Forty root canal treated teeth were randomly divided into two groups of 20 specimens each. Group 1 light-curing system: Excite and Tetric Flow; Group 2 dual cured system: All Bond 2+RelyX ARC. Translucent, double taper fibre posts were used (2.1/1.4mm diameter). The teeth were stored in NaCl 0.9% solution at 37 degrees C. A week later, the pull-out test was carried out on all specimens. Ten tested specimens for each group and their corresponding posts were processed for SEM observation. Statistical analysis was performed applying one-way analysis of variance (ANOVA) followed by T-test as post-hoc comparison at a significance level set at p<0.05. RESULTS: There is no statistically significant difference (p>0.05) between the light-curing system group (275.2+/-58.9N) and the dual cured one (301.4+/-40.1N). SEM observations confirm a good bond between the dentine and the post whatever the curing method employed. CONCLUSIONS: Dual curing of the All Bond 2+RelyX ARC system seems to be the most appropriate method since it allows to cure even those areas which would not be otherwise reached by light. On the other hand, in apical areas, the incomplete curing of the Excite+Tetric Flow system could improve the post adaptation and allow the achievement of both an improved apical seal and a more even distribution of the stress along the canal walls.

Adhesives↗

PubMed2004

Investigation into the nature of dentin resin tags: a scanning electron microscopic morphological analysis of demineralized bonded dentin.

STATEMENT OF PROBLEM: While the formation of the dentin/adhesive hybrid layer has been generally established, the infiltration and flow of the adhesive resin inside the acid treated dentinal tubules remains controversial. PURPOSE: The aim of the present study was to investigate and review the current interpretation of resin tags by means of scanning electron microscopic (SEM) observation. MATERIAL AND METHODS: Eight noncarious, human third molars were cut transversally and then longitudinally to obtain 8 middle-to-deep dentinal surfaces. The dentin was etched with 37% phosphoric acid (H 3 PO 4 ) gel for 10 seconds and then rinsed with water for 20 seconds. The dentin was kept moist by removing the excess water with a damp cotton pellet. The conditioned dentin was treated with a dentin bonding agent (Single Bond) and was light-polymerized for 20 seconds. A 0.2- to 0.5-mm layer of flowable composite (Tetric Flow) was then applied to the bonded dentin followed by 2 layers (2 mm each) of composite (Z 250). Each composite was light-polymerized for 40 seconds. Subsequently, the specimens were cut lengthwise into 2 halves and randomly divided into 4 groups (n=4), according to the surface preparation modality of the sectioned surface: Group EA: ethylenediamine tetraacetic acid, Group PA3: H 3 PO 4, Group PA120: H 3 PO 4 + NaOCl, and Group CA: HCl + NaOCl. Two additional teeth (Group N) were cut lengthwise into 2 halves and served as the control. The sectioned surfaces were treated with HCl and NaOCl. All specimens were processed for SEM observation. RESULTS: Specimens from Groups EA, PA3, PA120, CA, and N showed filamentous structures that were tens of microns long. Some filaments presented split-ends with hollow structures and very thin walls. Others made sharp hairpin turns indicating they were soft and compliant. CONCLUSIONS: Conventional SEM techniques, which are currently used to detect resin tags, actually identified filamentous organic structures, supposedly glycosaminoglycans, which were resistant to conventional specimen preparation techniques. The organic component showed a strong resemblance to the lamina limitans contained within the dentinal tubules. Over-reliance on SEM morphology has led to much confusion about the depth of penetration of resin tags.

Acid Etching, Dental↗