title: Chronic pain relief after the exposure of nitrous oxide during dental treatment: longitudinal retrospective study.
abstract: The objective was to investigate the effect of nitrous/oxygen in chronic pain. Seventy-seven chronic pain patients referred to dental treatment with conscious sedation with nitrous oxide/oxygen had their records included in this research. Data were collected regarding the location and intensity of pain by the visual analogue scale before and after the treatment. Statistical analysis was performed comparing pre- and post-treatment findings. It was observed a remarkable decrease in the prevalence of pain in this sample (only 18 patients still had chronic pain, p < 0.001) and in its intensity (p < 0.001). Patients that needed fewer sessions received higher proportions of nitrous oxide/oxygen. Nitrous oxide may be a tool to be used in the treatment of chronic pain, and future prospective studies are necessary to understand the underlying mechanisms and the effect of nitrous oxide/oxygen in patients according to the pain diagnosis and other characteristics.
authors.affiliation: Departamento de Neurologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Francisco Moreira
authors.initials: FM
authors.lastname: Mattos Júnior
authors.affiliation: Departamento de Neurologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Rafael Villanova
authors.initials: RV
authors.lastname: Mattos
authors.affiliation: Departamento de Neurologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Manoel Jacobsen
authors.initials: MJ
authors.lastname: Teixeira
authors.affiliation: Faculdade de Artes, Ciências e Humanidades, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Silvia Regina Dowgan Tesseroli de
authors.initials: SR
authors.lastname: Siqueira
authors.affiliation: Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Jose Tadeu Tesseroli de
authors.initials: JT
authors.lastname: Siqueira
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018685:Anesthetics, Inhalation / Q000627:therapeutic use*; D059350:Chronic Pain / Q000188:drug therapy*; D016292:Procedural Sedation / Q000379:methods*; D003729:Dental Care / Q000379:methods*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009059:Mouth Diseases / Q000628:therapy; D009609:Nitrous Oxide / Q000627:therapeutic use*; D010147:Pain Measurement; D012737:Sex Factors; D016896:Treatment Outcome; D064232:Visual Analog Scale; D055815:Young Adult
chemical_list: D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide