Etching on the edge: enamel loss under repeated and active HCl applications as a resin infiltration pretreatment
Abstract Considering that a single passive application of hydrochloric acid (HCl) as a resin infiltration pretreatment can remove between 20 and 45 µm of enamel and cause etching that extends up to 2 mm beyond the white spot lesions (WSLs), it is plausible that its repeated and active applications could result in a greater amount of dental tissue being removed. Objective To evaluate the enamel surface loss and micromorphology after etching with 15% HCl using two application methods (passive-P and active-A) and varying numbers of applications (C-placebo – 120 s; 1x HCl – 120 s; 2x HCl – 120 s + 120 s; 3x HCl – 120 s + 120 s + 120 s). Methodology Bovine incisors with ≤0.3 µm initial curvature were randomized into eight groups (n=12) based on microhardness, followed by WSL simulation. A central window was etched according to experimental conditions, and surface loss was assessed using optical profilometry and micromorphology via scanning electron microscopy (SEM). Two-way ANOVA and Tukey’s test were used for surface loss, and the chi-square test evaluated the association of experimental conditions with etching patterns (α=0.05). Results 1xP generated intermediate mean surface loss, positioned between the values observed for passive control (PC) and active control (AC), and those for 2xP and 3xP. Losses from active applications were significantly higher than passive ones and were increased by the number of applications. SEM showed Types II and III etching patterns and Type II was more frequent. There was no association between treatment and etching pattern. Conclusion Multiple and active HCl applications may raise concerns about removal of the remaining tooth structure, challenging the principles of minimal intervention dentistry.
Citação
@online{maria_paula_novaes_camargo2025,
author = {Maria Paula Novaes Camargo , Manna and Talita Portela ,
Pereira and Bruna De Oliveira , Iatarola and Mariele , Vertuan and
Ana Carolina , Magalhães and Denise Maria , Zezell and Luciana
Fávaro , Francisconi-Dos-Rios},
title = {Etching on the edge: enamel loss under repeated and active
HCl applications as a resin infiltration pretreatment},
volume = {33},
date = {2025-01-01},
doi = {10.1590/1678-7757-2025-0103},
langid = {pt-BR},
abstract = {Abstract Considering that a single passive application of
hydrochloric acid (HCl) as a resin infiltration pretreatment can
remove between 20 and 45 µm of enamel and cause etching that extends
up to 2 mm beyond the white spot lesions (WSLs), it is plausible
that its repeated and active applications could result in a greater
amount of dental tissue being removed. Objective To evaluate the
enamel surface loss and micromorphology after etching with 15\% HCl
using two application methods (passive-P and active-A) and varying
numbers of applications (C-placebo – 120 s; 1x HCl – 120 s; 2x HCl –
120 s + 120 s; 3x HCl – 120 s + 120 s + 120 s). Methodology Bovine
incisors with ≤0.3 µm initial curvature were randomized into eight
groups (n=12) based on microhardness, followed by WSL simulation. A
central window was etched according to experimental conditions, and
surface loss was assessed using optical profilometry and
micromorphology via scanning electron microscopy (SEM). Two-way
ANOVA and Tukey’s test were used for surface loss, and the
chi-square test evaluated the association of experimental conditions
with etching patterns (α=0.05). Results 1xP generated intermediate
mean surface loss, positioned between the values observed for
passive control (PC) and active control (AC), and those for 2xP and
3xP. Losses from active applications were significantly higher than
passive ones and were increased by the number of applications. SEM
showed Types II and III etching patterns and Type II was more
frequent. There was no association between treatment and etching
pattern. Conclusion Multiple and active HCl applications may raise
concerns about removal of the remaining tooth structure, challenging
the principles of minimal intervention dentistry.}
}