PublicaĆ§Ć£o
Extrafibrillar demineralization technique on the interfacial quality of dentin restored with self-adhesive composites
| dc.contributor.advisor | Delgado, AntĆ³nio Sales | |
| dc.contributor.author | Marques, Mariana Gomes Santos Godinho | |
| dc.date.accessioned | 2026-05-20T11:52:17Z | |
| dc.date.available | 2026-05-20T11:52:17Z | |
| dc.date.issued | 2025-10-25 | |
| dc.description | DissertaĆ§Ć£o para obtenĆ§Ć£o do grau de Mestre no Instituto UniversitĆ”rio Egas Moniz | |
| dc.description.abstract | Objectives: To evaluate whether an extrafibrillar demineralization technique can provide a dentin substrate capable of supporting the formation of a stable hybrid layer when restored with selfadhesive flowable resin composites (SAFRCs), potentially overcoming their limitations. Materials and Methods: Eighteen sound human molars were sectioned (Accutom-50, 0.350 mm/s, Struers, Denmark) and allocated into six groups (n=3), combining two SAFRCs (Vertiseā¢ Flow, Kerr; Constic, DMG) with three pretreatments: 37.5% phosphoric acid (control; OPA) for 15 s, glycol-chitosan methacrylate (GQ), and poly(amidoamine) dendrimers (PAMAM) for 60 s with active rubbing. Restorations were performed using the respective SAFRCs, applying a 0.5 mm layer and light-curing for 20 s (LED unit, 450ā470 nm, ~950 mW/cmĀ²). After 24 h in distilled water at 37 Ā°C, each tooth was sectioned into 2 mm slices and randomly assigned to Raman microspectroscopy or Massonās Trichrome staining. Chemical Transition Width (CTW, Ī¼m), defined as the 25ā75% rise of the Raman ratio profile, was calculated to assess interface abruptness. Data were analyzed using non-parametric statistics (Ī±=0.05). Results: Both pretreatment and SAFRC type influenced the dentināresin interface. Raman analysis showed that PAMAM generated the narrowest and most abrupt chemical transitions (CTW ā2.3 Ī¼m for VF; 1.1 Ī¼m for CC), whereas GQ produced broader interphases with persistent amide-rich residues (CTWā1.9 Ī¼m for VF; 0.8 Ī¼m for CC). OPA resulted in irregular profiles (CTW ā 2.5 Ī¼m for VF; 0.6 Ī¼m for CC). Despite no statistically significant group differences (p=0.147), PAMAM yielded cleaner interfaces with minimal collagen exposure, while GQ showed more red bands, especially with Constic. Conclusions: Extrafibrillar demineralization influenced the dentin substrate by modulating collagen exposure and interfacial organization, but it did not overcome the intrinsic limitations of SAFRCs. Refinement of pretreatment approaches and composite development is required to achieve predictable and durable adhesion. | eng |
| dc.description.abstract | Objetivos: Avaliar se uma tĆ©cnica de desmineralizaĆ§Ć£o extrafibrilar consegue proporcionar um substrato de dentina capaz de suportar a formaĆ§Ć£o de uma camada hĆbrida estĆ”vel, quando restaurado com resinas compostas fluidas auto-adesivas (SAFRCs), superando as suas limitaƧƵes. Materiais e mĆ©todos: Foram seccionados dezoito molares humanos hĆgidos (Accutom-50, 0.350 mm/s, Struers, Dinamarca) e distribuĆdos em seis grupos (n=3), combinando dois SAFRCs (Vertiseā¢ Flow, Kerr; Constic, DMG) com trĆŖs prĆ©-tratamentos: Ć”cido fosfĆ³rico a 37,5% (controlo; OPA) durante 15 s, quitosano-metacrilato de glicol (GQ) e dendrĆmeros de poli(amidoamina) (PAMAM) durante 60 s com fricĆ§Ć£o ativa. As restauraƧƵes foram realizadas com aplicaĆ§Ć£o de uma camada de 0,5 mm de SAFRC, seguida de fotopolimerizaĆ§Ć£o durante 20 s (LED, 450ā470 nm, ~950 mW/cmĀ²). ApĆ³s 24 h em Ć”gua destilada a 37 Ā°C, os dentes foram cortados em fatias de 2 mm e aleatoriamente atribuĆdos Ć microespectroscopia Raman ou coloraĆ§Ć£o tricrĆ³mica de Masson. A largura de transiĆ§Ć£o quĆmica (CTW, Ī¼m), definida como a variaĆ§Ć£o de 25ā75% no perfil de razĆ£o Raman, foi calculada para avaliar a abruptidade da interface. Os dados foram analisados com estatĆstica nĆ£o paramĆ©trica (Ī±=0,05). Resultados: O tipo de prĆ©-tratamento e de compĆ³sito influenciou a interface dentinaāresina. A anĆ”lise Raman revelou que o PAMAM produziu transiƧƵes quĆmicas mais abruptas (CTW ā2,3 Ī¼m para VF; 1,1 Ī¼m para CC), enquanto o GQ gerou interfaces mais amplas e com resĆduos ricos em amidas (CTWā1,9 Ī¼m para VF; 0,8 Ī¼m para CC). OPA apresentou perfis irregulares (CTWā2,5 Ī¼m para VF; 0,6 Ī¼m para CC). Apesar de nĆ£o haver diferenƧas estatisticamente significativas entre grupos (p=0,147), o PAMAM resultou em interfaces mais limpas e com menor exposiĆ§Ć£o de colagĆ©nio, ao contrĆ”rio do GQ. ConclusƵes: A desmineralizaĆ§Ć£o extrafibrilar influenciou a exposiĆ§Ć£o de colagĆ©nio e a organizaĆ§Ć£o interfacial, mas nĆ£o superou as limitaƧƵes dos SAFRCs. SĆ£o necessĆ”rios avanƧos nos prĆ©-tratamentos e nos compĆ³sitos para adesĆ£o previsĆvel e duradouro. | por |
| dc.identifier.tid | 204048117 | |
| dc.identifier.uri | http://hdl.handle.net/10400.26/63212 | |
| dc.language.iso | eng | |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | |
| dc.subject | Extrafibrillar demineralization | |
| dc.subject | Dentin | |
| dc.subject | Self-adhesive resin composites | |
| dc.subject | Adhesion | |
| dc.title | Extrafibrillar demineralization technique on the interfacial quality of dentin restored with self-adhesive composites | eng |
| dc.type | master thesis | |
| dspace.entity.type | Publication | |
| thesis.degree.name | Mestrado Integrado em Medicina DentƔria |
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