Ionic 3 provider does not update


Hi, i am really new in ionic and i am working on an existing app. pages included in side menu of the app are defined in providers as : page-service.ts. i want to change titles of pages, i change their title in providers but when i run the app i see the old titles in the side menu. i have already changed page titles in all the html pages and it is fine but i have problem with the side menu titles.
the instruction of this provider page is :
import { Injectable } from ‘@angular/core’;
import {PageInterface} from “…/models/page-interface”;

export class PageService {

pages: PageInterface = [
{ title: ‘Inicio’, pageName: ‘TabsPage’, tabComponent: ‘HomePage’, index: 0, icon: ‘icon_inicio.png’ },
{ title: ‘Perfil usuario’, pageName: ‘ProfilePage’, icon: ‘icon_perfil.png’ },
{ title: ‘Datos clínicos’, pageName: ‘MedicalDataPage’, icon: ‘icon_datos.png’ },
{ title: ‘Cerrar sesión’, pageName: ‘’, icon: ‘icon_logout.png’, logsOut: true },

public getPages() : PageInterface {
return this.pages;

and i am using:
Ionic Framework: 3.9.2
Ionic App Scripts: 3.1.11
Angular Core: 5.2.11
Angular Compiler CLI: 5.2.11
Node: 11.7.0
OS Platform: Windows 7
Navigator Platform: Win32