sensitivity of amalgam restorations
Younger patients, females, and pre-operative sensitivity to cold may be predictive of
postoperative sensitivity following placement of amalgam restorations.
Postoperative sensitivity is a common clinical problem with restorative treatments.
Study aims: To identify factors that may be predictive ofreported postoperative
sensitivity to cold following placement of class I and II amalgam restorations in
primary carious lesions.
Materials and methods:
One hundred and twenty patients were recruited. Patients were telephoned on days
two and seven postoperatively and asked about sensitivity to cold and its intensity. If
sensitivity remained up to day seven, patients were also contacted ondays 30 and 90.
Of the 51 teeth that had sensitivity at day two, 17 experienced mild pain, 26 were
moderately painful and eight had severe pain. The percentage of females experiencing
postoperative sensitivity was higher than that of males at days two, seven and 30
(P=0.000, 0.016 and 0.028, respectively). Younger patients reported significantly more
postoperative sensitivity thanolder ones at day two (P=0.010) but not at days seven
and 30 (P=0.157 and 0.877). Postoperative sensitivity did not differ among the
different tooth types at days two, seven and 30 (P=0.219, 0.236 and 0.338,
respectively), nor with respect to class I and class II cavities at days two, seven and 30
(P=0.219, 0.769 and 0.259, respectively). Patients who had some pre-operative pain
hadsignificantly more postoperative sensitivity (P=0.000, 0.000, and 0.004 at days
two, seven and 30, respectively).
Regression analysis suggested that younger patients, females, and pre-operative
sensitivity to cold might be predictive of postoperative sensitivity following placement
of amalgam restorations.
journal of the Irish Dental Association 2009; 55 (2): 87 -. 91.
IntroductionPostoperative sensitivity following the
routine placement of an amalgam
restoration continues to be an unpredictable
problem in restorative dentistry.^"^ It is
usually encountered during the first few days
following placement of the restoration,''
although its incidence and severity varies
between studies. In one study, about onequarter
of patients with new amalgam
restorations experiencedpostoperative pain,^
while elsewhere, half of the study subjects
reported postoperative sensitivity.^
Microleakage around the margins of the
newly placed restoration is believed to be
one of the main causes of postoperative pain.
The most accepted explanation for tooth
sensitivity is known as the hydrodynamic
theory.* According to this theory, fluid
movement in the dentinal tubules will beinterpreted as pain by pulpal
Corrosion products from dental amalgam are
believed to produce a gradual reduction of
postoperative sensitivity through obliteration
of the tooth restoration interfacial space.'
However, this may take several months to
occur, and a variety of bases and liners have
been used to compensate for the initial
period of postoperative sensitivity.'Cavity
varnishes have been routinely used under
amalgam restorations to act as interim
sealers while corrosion products form.'
Traditionally calcium hydroxide was used as
Volume 55 (2J : April/May 2009 87
Journal of the Irish Dental Association
a cavity liner,'" but more recently, dentine bonding agents and
amalgam bonding have gained popularity as cavity liners."''^'" The
useof glass ionomer cements as a base under amalgam restorations
has been found to reduce sensitivity to cold.'* Furthermore,
disinfection of the cavity preparation prior to restoration is gaining
wider clinical acceptance.'^''
Studies have shown that the depth of the cavity is a significant factor
to be considered in relation to postoperative sensitivity."''* On the
other hand, Cordan et...