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| Author(s): |
Rodrigo Arruda Vasconcelos
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba |
| Defense date: | 2021-03-23 |
| Examining board members: |
Brenda Paula Figueiredo de Almeida Gomes;
Marcia Carneiro Valera;
Rogerio de Castilho Jacinto;
Flaviana Bombarda de Andrade Ferreira;
Marlos Barbosa Ribeiro
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| Advisor: | Brenda Paula Figueiredo de Almeida Gomes |
| Abstract | |
This Thesis was divided into 3 chapter with the following objectives: Chapter I) To investigate the microbial profile, levels of endotoxins, lipoteichoic acid, cytokines (TNF-?, IL-1?, IL-1?, IL-10), matrix metaloproteinases (MMP-2, -3, -8, -9, -13), prostaglandin E2 (PGE2), substance P and perception of pain in the different stages of endodontic treatment, performed with 2% chlorhexidine (CHX) or 6% sodium hypochlorite (NaOCl), and calcium hydroxide-based intracanal medication (ICM) in teeth with symptomatic irreversible pulpitis (SIP); Chapter II) To quantify the levels of TGF-?1 from root dentine matrix using different irrigation protocols and to evaluate the antimicrobial activity in order to optimise treatment strategies. Furthermore, this chapter evaluated the amount of apically extruded debris after chemo-mechanical preparation (CMP) associated with passive ultrasonic irrigation (PUI) using four different root canal irrigants, namely, 6% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) gel + saline solution (2% CHXg + SS), 2% CHX solution (2% CHXs) and SS alone; and Chapter III) To point out the increasing number of patient with a need of endodontic treatment do to acute symptoms and to hypothesise its association with psychological disorders related to the SARS-CoV-2 pandemic. Methods: Chapter I) Twenty teeth with SIP were selected. Clinical samples were collected from root canals and periapical tissues before CMP, after CMP (microbiological samples), 48 hours after CMP (immunological samples), and after 30 days of calcium hydroxide-based ICM. Microbial profile was assessed by culture method, nested PCR (polymerase chain reaction), and checkerboard DNA-DNA hybridization. The levels of endotoxins were quantified by sing LAL Pyrogent 5000. The levels of LTA, substance P and prostaglandin E2 (PGE2) were quantified by using ELISA, and the levels of cytokines and matrix metalloproteinases using multiplex immunoassay. Perception of pain was assessed by using a visual analogue scale; Chapter II) Liberation of TGF-?1 from dentine matrix was quantified by using ELISA after protocols simulating single (etidronic acid + 2% NaOCl or etidronic + distilled water) or two sessions (2% NaOCl + calcium hydroxide/2% CHX gel + 17% EDTA or 2% CHX gel + calcium hydroxide/2% CHX gel + 17% EDTA). Antimicrobial activity was assessed by using confocal laser scanning microscope after 21 days of contamination with saliva. The second study, a total of 60 lower incisors were selected. CMP was performed by using Reciproc instrument and passive ultrasonic irrigation. Protocols used were 6% NaOCl, 2% CHX gel associated with saline solution, 2% CHX solution and saline solution alone. Extruded debris were collected in Eppendorf tubes and the amount of debris was calculated by the difference between the final and initial weight of the tubes (in grams); Chapter III) It was written a general comment with regard to possible relationship between SIP and psychiatric disturbs during the pandemic. Significance level was set at 5% in all tests. Results: Chapter I) Endodontic treatment was effective in reducing the levels of bacteria e their virulence factors, as well as the levels of cytokines, matrix metalloproteinases, substance P and PGE2. Resistant microbial species including E. faecalis and F. nucleatum were detected after CMP and ICM; Chapter II) Higher levels of TGF-?1 were released after ICM and 2% CHX gel as root canal irrigant; Endodontic treatment performed with 2% CHX gel + saline solution provided lower levels of extruded debris; Chapter III) Although the number of dental appointments is reduced, increase number of patients presenting with pulpitis has been observed. Furthermore, it has been reported increased number of patients with psychological disorders, and consequently, higher levels of inflammatory mediators. In conclusion: Chapter I) Teeth with SIP present a complex polymicrobial profile with the presence of Gram-positive, Gram-negative, facultative, and strict anaerobes. Endodontic treatment was effective in reducing the levels of bacteria, endotoxins and lipoteichoic acid in teeth with SIP. Endodontic treatment was effective in reducing the levels of inflammatory biomarkers. CHX and NaOCl presented similar effects in the analysed parameters. Chapter II) NaOCl hampers the liberation of TGF-?1 from dentine matrix, which may reduce the chances of a conductive environment for revitalisation. Chelating substances (EDTA or HEDP) and CHX allowed the liberation of TGF-?1 from dentine matrix, beside presenting antimicrobial activity; Apically extruded debris were observed using passive ultrasonic irrigation. CMP performed with 2% CHX gel associated with saline solution minimised debris extrusion; Chapter III) The recent increase in the number of patients seeking endodontic treatment due to acute symptomatology could be related to the change of the individual's habits and to the psychiatric disorders triggered by the fear of SARS-CoV-2 and the restrictive/isolation measures imposed during the outbreak (AU) | |
| FAPESP's process: | 17/25242-8 - Clinical, microbiological and immunological monitoring of patients undertaken to endodontic therapy with diagnosis of irreversible Pulpitis |
| Grantee: | Rodrigo Arruda Vasconcelos |
| Support Opportunities: | Scholarships in Brazil - Doctorate |