GERODONTOLOGY
(29-36), monitoring different systems’ behavior and
mentioning varying results. The incidence ranges
from 1.3% - 10% (36) with a mean prevalence of
1.6% (37). Retrospective clinical studies have
shown that the separation incidence for rotary
NiTi instruments is 7 to 8 times greater than that of
hand instruments (38, 39).
The use of rotary instruments can be significantly
improved with the combined use of lubricant
agents inside the root canal. These agents facilitate
the movement of the instrument inside the narrow
environment of the root canal, by decreasing cyclic
fatigue and torque load of rotary instruments,
especially when they have extra chelating action
(40). This way the clinician can handle the rotary
instruments more easily and decrease the chance
of iatrogenic events and particularly instrument
separation. The application of sodium hypochlorite
and aqueous chelating solutions (i.e. EDTA)
compared to agents in paste form (PC-Prep) has
been shown to cause less instruments’ fractures (41).
2.2. Dentine microcracks
The use of rotary systems for root canal
preparation has been related to the creation
of deformations and mostly microcracks in
the inner walls of dentine due to tensions’
accumulation, especially in the apical third (4244). Similar deformations were not observed
after preparation with hand files.
Dentine loses its elasticity with age.
Consequently, it is possible that these
microcracks appear to greater extend in
elderly teeth, which may affect their prognosis
and increase the possibility of a root fracture.
However, this hypothesis has not yet been
confirmed.
Discussion
The investigation of the existing literature has
shown that more research is necessary on the
application of rotary systems in older people and
more emphasis should be placed on Geriatric
Endodontics.
Conclusions
Rotary systems