HA016 - Hatton
Área: 8 - Periodontia

Analysis of the oral biofilm diversity and protein profile of saliva and acquired enamel pellicle of individuals with periodontitis
Amado PPP, Kawamoto D, Saraiva L, Siqueira WL, Mayer MPA
Microbiologia - UNIVERSIDADE DE SÃO PAULO
Conflito de interesse: Não há conflito de interesse

The etiology of Grade C/molar-incisor pattern periodontitis (GC/MIP), Localized Aggressive Periodontits, is poorly understood. We determinate the oral and gut microbiomes, inflammatory mediators and whole saliva (WS) and acquired enamel pellicle (AEP) proteomes of Afro-descendants with GC/MIP and their age/race/gender-matched non-affected controls (n=7). Biofilms from supra/subgingival sites (OB) and feces were analyzed by 16S rRNA sequencing. WS and AEP proteomes were determined by LC-ESI-MS/MS. Cytokines/chemokines WS and WS proteolytic activity were evaluated. GC/MIP supragingival biofilm presented greater abundance of opportunistic bacteria. Synergistetes and Spirochaetae were increased whereas Actinobacteria was reduced in GC/MIP OB compared to controls. GC/MIP oral microbiome presented reduction in commensals and enrichment in A. actinomycetemcomitans and sulfidogenic bacteria (SB). SB was more abundant in fecal microbiome of GC/MIP. Increase of CCL2/CCL25 and decrease of CCL17/CCL27 were observed in GC/MIP. AEP proteins such as ALMS1 and Cystatin-S, and WS proteins such as alpha-enolase, profilin-1, dystonin, A2ML1, alpha-actinin-4 and IGHA1 were differentially detected in the studied groups. WS proteolytic activity was more pronounced in GC/MIP than in controls.
Dysbiosis in GC/MIP is not restricted to periodontitis sites, suggesting that antimicrobial therapies should address the whole mouth and the gut. WS and AEP proteins, and chemokines have potential to be used as biomarkers of GC/MIP.
(Apoio: FAPESP  N° 2015/00259-0)

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HA017 - Hatton
Área: 10 - Implantodontia básica e biomateriais

Effect of topical PTH 1-34 added to bioglass on peri-implant defect in orchiectomized rats
Gomes-Ferreira PHS, Micheletti C, Frigério PB, Monteiro NG, De-Souza-batista FR, Lisboa Filho PN, Grandfield K, Okamoto R
Cirurgia e Clínica Integrada - UNIVERSIDADE ESTADUAL PAULISTA - ARAÇATUBA
Conflito de interesse: Não há conflito de interesse

The objective of this work was to evaluate a bioglass functionalized with parathyroid hormone (PTH 1-34) using the sonochemistry technique in peri-implant defects in orchiectomized rats. 96 rats were divided into two groups, i.e. SHAM - control surgery and ORQ - orchiectomy. Each group was subdivided into three sub-groups: CLOT (pre-implant defect, without bioglass); BG (pre-implant defect and bioglass); BGPTH (pre-implant defect and bioglass functionalized with topical PTH 1-34). Each animal received an implant in the tibial metaphysis. Euthanasia occurred at 30 and 60 days after implant placement. MicroCT, laser confocal microscopy, biomechanics, immunohistochemistry, PCR-RT, and electron microscopyanalyses (energy dispersive x-ray spectroscopy, scanning electron microscopy and transmission electron microscopy (TEM)) were performed. As suggested by microtomographic parameters, biomaterial with or without PTH 1-34 showed improvement in bone repair. Analysis of fluorochromes and biomechanics indicated that the functionalized biomaterial increased bone regeneration in the ORQ group to the same level as the SHAM group without PTH 1-34. Immunohistochemistry and PCR analyses show positive changes in groups with PTH 1-34. Nanoscale imaging with TEM suggested the presence of a greater dissolution area of the bioglass and greater organization of collagen fibers in the ORQ BGPTH group.
Overall, the functionalization of bioglass with PTH 1-34 showed improvement in bone regeneration and resulted to be even more effective in the osteoporotic animals.
(Apoio: FAPs - FAPESP  N° 2017/08187-3)

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HA018 - Hatton
Área: 10 - Implantodontia - clínica protética

Stress distribution and micro-gap formation at the abutment-implant interface: a three-dimensional finite element analysis
Tonin BSH, He Y, Ye N, Chew HP, Fok A
Odontologia Restauradora - UNIVERSIDADE DE SÃO PAULO - RIBEIRÃO PRETO
Conflito de interesse: Não há conflito de interesse

This study aims to investigate the stress distribution in the prosthetic screw and the formation of micro-gaps at the implant-abutment interface of conical connections with titanium (Ti) and yttrium-stabilized zirconium (Y-TZP) abutments. Three-dimensional finite models of the above implant-abutment connections were created. The analyses were conducted using a screw torque of 20 N.cm and an oblique load at 30º from 10 to 100 N at intervals of 10 N, and from 120 to 280 N at intervals of 20 N. The stress distribution, the micro-gap formation process, and the critical load for bridging of the internal implant space, and the size of the micro-gaps were evaluated. The models showed similar patterns of von Mises stress which was mainly concentrated at the top and in the middle of the screw. For all the models, the implant-abutment contact area decreased with increasing load. Above 140 N, bridging of the internal implant space was found when over 70% of the interfacial area was opened. Under 280 N, more than 90% of the interface had a gap larger than 30 mm.
Overall, this study does not indicate any obvious advantage of Ti or Y-TZP abutments over each other. Although the simulated micro-gaps and bridging of the internal implant space can explain the presence of bacteria detected clinically inside implants, the relationship between bacterial invasion and micro-gaps needs further research.
(Apoio: CAPES  N° 88881-187982/2018-01)

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