Applications of ultrasonics in endodontics

APPLICATIONS OF ULTRASONICS IN ENDODONTICS
PRESENTER GUIDE
DR. METTINA DR.GEETA I.B.

CONTENTS
 INTRODUCTION
 APPLICATIONS IN ENDODONTICS
 ULTRASONICS & RETREATMENT
 ACCESS REFINEMENT
 CALCIFICATION MANAGEMENT
 SEPARATED INSTRUMENT RETRIEVAL
 POST RETRIEVAL
 PASSIVE ULTRASONIC IRRIGATION
 CONDENSATION OF GUTTA PERCHA
 PLACEMENT OF MTA
 ROOT END RESECTION
 ROOT CANAL PREPARATION
 CONCLUSION

INTRODUCTION
 Ultrasound is sound energy with a frequency above the range of human hearing, which is 20 kHz. The
range of frequencies employed in the original ultrasonic units was between 25 and 40 kHz .
 Subsequently the so-called low-frequency ultrasonic handpieces operating from 1 to 8 kHz were
developed which produce lower shear stresses causing less alteration to tooth surface.

INTRODUCTION
 The first is magnetostriction, which converts electromagnetic energy into mechanical energy. A stack of
magnetostrictive metal strips in a handpiece is subjected to a standing and alternating magnetic field, as
a result of which vibrations are produced.
 The second method is based on the piezoelectric principle, in which a crystal is used that changes
dimension when an electrical charge is applied. Deformation of this crystal is converted into mechanical
oscillation without producing heat

INTRODUCTION

• The concept of using Ultrasonics in endodontics was first introduced by
Richman in 1957.
• However, it was not until Martin et al demonstrated the ability of
ultrasonically activated K-type files to cut dentin that this application
found common use in the preparation of root canals before filling and
obturation.
• The term endosonics was coined by Martin and Cunningham and was
defined as the ultrasonic and synergistic system of root canal
instrumentation and disinfection.

APPLICATIONS OF ULTRASONICS IN ENDODONTICS
Access refinement
Calcification
managemen
t
Removal of
intracanal
obstructions
Irrigant
activation
Condensation of
Gutta percha
Placement of
MTA
Root End
preparation
Root canal
preparation

TRADITIONAL METHODS ? ARE THEY EFFICIENT?
 The traditional technique uses K files or H
files, along with chemical solvents such as
xylol or chloroform to soften the gutta-
percha component of the obturation
material, allowing further penetration of
the file deeper into the canal.
 Gates burs can be used for the coronal
and middle thirds in root canals with very
compact fillings.
 Currently, WaveOne® (Dentsply
Maillefer, Switzerland) and Reciproc®
(VDW, Germany) instruments, of
reciprocating motion, have also been
suggested to remove gutta percha with
very good results reported in the
literature.

Abstract
Introduction
Although success of endodontic therapy has significantly improved in the last few decades due to the introduction of novel materials and techniques, failures of endodontic
therapy requiring re-treatment still comprise a significant percentage of patients requiring root canal treatment.
Aim
To evaluate and compare the effective removal of gutta percha and sealer, amount of apical debris extrusion and time required for gutta percha removal using various
endodontic files.
Materials and Methods
Total 48 extracted mandibular premolars were mounted on acrylic blocks and endodontic procedure was carried out using size 40 K file and obturated using guttapercha and
zinc oxide eugenol sealer. After one month storage, samples were decoronated, mounted on screw capped vials and subjected to removal of obturated material by four
instruments: H files, safe sided H files, protaper universal retreatment rotary system and ultrasonic retreatment tip, grouped as 1, 2, 3, and 4 respectively. Only 2mm of obturated
material from the coronal part was removed using no. 3 Gates Glidden drill, guttapercha was softened with a drop of xylene for 2 mins for each canal and retreatment was
performed.
The retreatment procedure was said to be complete when no visible debris were observed on the instrument flutes. The samples split into two halves and examined under
stereomicroscope, photographed, assessed using AUTOCAD software and percentage of remaining filling material in coronal, middle, apical thirds of the canal was calculated in
mm2. Retreatment time was recorded in seconds and apically extruded debris was assessed by microbalance in grams for each tooth. The data was analyzed by using descriptive
statistics, ANOVA and Scheffe’s post hoc test through SPSS for windows (v 16.0).
Results
The ultrasonic retreatment tip had less percentage of residual guttapercha/sealer, shorter mean operating time and little apical extrusion with a significant difference (p<0.05)
between the other groups.
Conclusion
All techniques retained guttapercha/sealer remnants within the root canal. The ultrasonic retreatment tip proved to be an efficient method of removing obturated material. It
was fastest with least apical debris extrusion.
Efficacy of Different Methods for Removing Root Canal Filling Material in Retreatment - An In-vitro Study
Swetha Kasam 1 and Annapoorna Ballagere Mariswamy2

ACCESS REFINEMENT
 A lack of a straight-line access is arguably the leading cause of separation, perforation, and the inability
to negotiate files to the radiographic terminus.
 The introduction of the microscope, access burs, and US has greatly reduced these risks.
 Microscopic visualization and ultrasonic instruments are a safe and effective combination to achieve
optimal results. In difficult-to-treat teeth such as molars, US has proven to be useful for access
preparation, not only for finding canals, but also for reducing the time and the predictability of the
treatment.
 One of the more important advantages of ultrasonic tips is that they do not rotate, thus enhancing
safety and control, while maintaining a high cutting efficiency.
 This is especially important when the risk of perforation is high. The visual access and superior control
that ultrasonic cutting tips provide during access procedures make them a most convenient tool,
especially when treating difficult molars

ACCESS REFINEMENT
 The phase of finding canal orifices should
be carried out with thinner and longer
tips that facilitate working in deeper
areas while maintaining clear vision.

MB 2 SCOUTING
Studies on maxillary first molar anatomy show that the second mesiobuccal canal (MB2) is present in 65-
90% of the cases. Ultrasonic instrumentation with a diamond coated insert (E2D or E6D) along the line
connecting the primary mesiobuccal and the palatal canals will often reveal the MB2 orifice location.
Clinically, the use of magnification and ultrasonics is the most effective technique to locate the MB2 canal.

FINDING CALCIFIED CANALS/ PULP STONE REMOVAL
 A troughing tip is a good choice for this task .
 Bigger tips with a limited diamond coated extension should be used during the initial phase of removing
calcification, interferences, materials, and secondary dentin, as they offer maximum cutting efficiency and
enhance control while working in the pulp chamber .
• Calcification of the dental pulp may be discrete or diffuse in its form.
• Discrete calcification results in the formation of pulp stones, denticles, or nodules.
• Diffuse calcification results in a symmetric reduction in the size of the pulp chamber and the radicular pulp
space, which is more commonly observed in older patients.

Applications of ultrasonics in endodontics

Ultrasonic Management of Calcified Canal: A Case Report
Prasad Koli1, , Madhu Pujar1, Viraj Yalgi1, Veerendra Uppin1, Hemant Vagarali1, Namrata
Hosmani1

SEPARATED INSTRUMENT RETRIEVAL
BROKEN INSTRUMENT REMOVAL The Endodontic Challenge
by Clifford J. Ruddle, DDS

SEPARATED INSTRUMENTS – THE CHALLENGE
1. Creating proper coronal & radicular access is a very important step
2. A Proper staging platform should be created for instrument retrieval.

PRIMARY REMOVAL METHOD
 The primary method to remove a broken file segment utilizes the microscope in conjunction with
optimally designed ultrasonic instruments, such as the ProUltra ENDO insert tips (Dentsply Sirona)

FRACTURED INSTRUMENT RETRIEVAL

CASE REPORT
Ultrasonic Technique to Retrieve a Rotary Nickel-Titanium File Broken Beyond the Apex
and a Stainless Steel File from the Root Canal of a Mandibular Molar: A Case Report
Vineet Agrawal, 1 Sonali Kapoor,2 and Mukesh Patel3
Abstract
During endodontic treatment, clinicians may face endodontic procedural mishaps such as broken instruments, which is a complex
situation especially when the file breaks beyond the apex. This condition is associated with potential risk of contamination, which
compromises the healing process. Management of a broken instrument beyond the apex is difficult and time consuming and
requires creativity as well as clinical knowledge and skills. Several devices and techniques have been developed to retrieve the
fractured instruments, but none are consistently successful. This case report describes a technique using modern ultrasonic tips for
retrieval of broken instruments separated beyond the apex.

REMOVAL OF OLD POSTS
 Nonsurgical endodontic retreatment of teeth restored with intraradicular posts continues to present a
challenge because of the inherent difficulties of removing posts without weakening, perforating, or
fracturing the remaining root structure .
 Ultrasonics has provided clinicians with a useful adjunct to facilitate post removal with minimal loss of
tooth structure and root damage.
 Many studies have focused on the removal of metallic posts; however, retreatment of fiber-reinforced
composite posts cemented with adhesive systems presents a new challenge in cases in which
endodontic treatment has failed .
 Different bur kits have been proposed to remove fiber posts; however, the preservation of maximum
root structure requires the use of specific ultrasonic tips & adequate magnification.

REMOVAL OF OLD POSTS
 The disruption of the composite structure through the action of ultrasonic vibration seems to be the most
effective technique in fiber post removal.
 Esthetic white posts are more difficult to remove because their color matches that of dentin, whereas the black
carbon fiber posts clearly contrast to dentin.
 Removal is done in a dry field using a continuous stream of air with direct vision of the ultrasonic tip and the
coronal portion of the post, alternated by air and water spray to clean the remnants of fibers and dentin.
 It is important that the entire composite material that was used in the luting procedure be removed.
 The absence of a water spray seems to increase the action of US when applied to posts cemented with resin
cements, possibly because of the increase in heat.
 It has been observed that the capacity of adhesion of a resin cement, and consequently mechanical retention,
gradually reduces with the number of thermal cycles.
 Several studies point to the fact that ultrasonic vibration of posts facilitates their removal while conserving
tooth structure and reducing the possibility of fractures or root perforations

STEPS IN REMOVAL OF OLD POSTS
Break the seal between the post and the tooth
structure.
Reduce the extraradicular portion of the post to
the same diameter as the intraradicular portion
to reduce tension.
Trephining around the post using a round bur.
A basic spreader tip to be placed to further break
down the integrity of the cement or resin, usually
resulting in loosening of the post.

ACTIVATION OF IRRIGANTS- THE NEED
Isthmuses
C Shaped canals Apical vapor lockRamifications

PASSIVE ULTRASONIC IRRIGATION
 The effectiveness of irrigation relies on both the mechanical
flushing action and the chemical ability of irrigants to dissolve
tissue.
 Acoustic streaming, as described by Ahmad et al., has been
shown to produce sufficient shear forces to dislodge debris in
instrumented canals. When files were activated with ultrasonic
energy in a passive manner, acoustic streaming was sufficient
to produce significantly cleaner canals compared with hand
filing alone.
 Jensen et al;The flushing action of irrigants may be enhanced
by using US . This seems to improve the efficacy of irrigation
solutions in removing organic and inorganic debris from root
canal walls.
 A possible explanation for the improved action is that a much
higher velocity and volume of irrigant flow is created in the
canal during ultrasonic irrigation.

CONDENSATION OF GUTTA PERCHA
 Ultrasonically activated spreaders have been used to thermoplasticize gutta-percha in a warm lateral
condensation technique.
 In some in vitro experiments, this was demonstrated to be superior to conventional lateral condensation
with respect to sealing properties and density of gutta-percha.
 Ultrasonic spreaders that vibrate linearly and produce heat, thus thermoplasticizing the gutta-percha,
achieved a more homogeneous mass with a decrease in number and size of voids and produced a more
complete three-dimensional obturation of the root canal system .

ULTRASONIC CONDENSATION OF GP
A number of obturation protocols have been described for ultrasonic
condensation of gutta-percha:
• (a) ultrasonic softening of the master cone followed by cold lateral condensation
• (b) one or two times of ultrasonic activation after completion of cold lateral condensation ;
• (c) ultrasonic activation after placement of each second accessory cone
• (d) ultrasonic activation after placement of each accessory cone .

CONDENSATION OF GP
 It was observed that heat was generated only during ultrasonic activation, and the plugger appeared to
cool rapidly once activation ceased .
 The size of the heat carrier (ultrasonic spreader) can be chosen to match the diameter of the root canal,
and the ultrasonic spreader can be curved to match the curvature of the root canal.
 Gutta-percha does not stick to the ultrasonic file when the ultrasonic unit is activated .
 The low temperature produced by the unit at its lowest power setting may result in less volumetric
changes of gutta-percha upon cooling

CONDENSATION OF GP - STEPS
 The obturation technique recommended when using the ultrasonic techniques consists of
 Initial placement of a guttapercha cone to the working length followed by cold lateral condensation of two
or three accessory cones using a finger spreader.
 The ultrasonic spreader is then placed into the center of the gutta-percha mass 1 mm short of the working
length and activated at intermediate power.
 After activation, the ultrasonic spreader is removed, and an additional accessory cone is placed.
 Followed by energizing with the activated ultrasonic spreader.
 This process is repeated until the canal is filled.
 During each subsequent step, the ultrasonic spreader should be placed slightly more coronally.
 The ultrasonic spreader must be in the mass of gutta-percha for about 10 seconds to achieve
thermoplasticization. Leaving it in the canal for more than 10 seconds can produce a rise in temperature that
is damaging to the root surface

Ultrasonic condensation of gutta-percha: An in vitro dye penetration and
scanning electron microscopic study
Kirk R.BaumgardnerBS, DDS12KeithV. KrellDDS, MS, MA2
Lateral condensation of gutta-percha with and without ultrasonic activation of the spreader was compared by
use of dye penetration analysis and scanning electron photomicrographs of the gutta-percha fills in extracted
human incisors and canines. The root canal fillings in three groups of 10 teeth each were laterally condensed
using an ultrasonically activated spreader, a fine finger spreader, or a nonactivated ultrasonic spreader.
Significantly less apical dye penetration occurred when teeth were obturated using an ultrasonically activated
spreader as compared with manual condensation with fine finger spreaders. The ultrasonically condensed
gutta-percha mass was more homogeneous with fewer voids compared with guttapercha masses from the two
groups that were condensed without ultrasonic activation. A correlation between apical microleakage and the
appearance of the gutta-percha mass was seen. All teeth with well-condensed, more homogeneous fillings had
low dye penetration. All teeth with a high extent of dye penetration had poorly condensed, less homogeneous
fillings. However, not all teeth that had poorly condensed fillings had high dye penetration.

ULTRASONIC PLACEMENT OF MTA
 Witherspoon and Ham described the use of US to aid in the placement of MTA.
 The inherent irregularities and divergent nature of some open apices may predispose the material to
marginal gaps at the dentin interface.
 It was demonstrated that, with the adjunct of US, a significantly better seal with MTA was achieved.
 Placement of MTA with ultrasonic vibration and an endodontic condenser improved the flow, settling,
and compaction of MTA.
 Ultrasonically condensed MTA appeared denser radiographically, with fewer voids .

STEPS INVOLVED
Selecting a condenser tip,
Picking up and placing the MTA with
the ultrasonic tip,
Activating the tip and slowly moving
the MTA material down using a 1- to
2-mm vertical packing motion.
Direct ultrasonic energy will vibrate
and generate a wavelike motion, which
facilitates moving and adapting the
cement to the canal walls .

ULTRASONIC PLACEMENT OF MTA
 In a case of repairing a defect apical to the canal curvature, Ruddle recommends incrementally placing
MTA deep into a canal, then shepherding it around the curvature with a flexible trimmed gutta-percha
cone utilized as a plugger.
 A precurved 15 or 20 stainless steel file is then inserted into the material and placed to within 1 or 2 mm
of the working length.
 This is followed by indirect ultrasound, which involves placing the working end of an ultrasonic
instrument on the shaft of the file.
 This vibratory energy encourages MTA to move and conform to the configurations of the canal laterally
as well as controlling its movement.

ROOT END RESECTION/ SURGICAL ENDODONTICS
 Conventionally root end preparation has been done using a handpiece & bur, but that system could not
be used in cases with limited working space or in teeth with large oval canals.
 Since Sonically or Ultrasonically driven microsurgical retro tips became commercially available in the
early 1990s , this new technique of retrograde root canal instrumentation has been established as an
essential adjunct in periradicular surgery
Conventional root-end cavity preparation using rotary
burs in a micro handpiece is faced with several problems ,
such as
• A cavity preparation not being parallel to the canal,
• Difficult access to the root end,
• Risk of lingual perforation of the root.
• Inability to prepare to a sufficient depth, thus
compromising retention of the root-end filling material

ROOT CANAL PREPARATION
 Ultrasonic devices were introduced for use in root
canal preparation in 1957 by Richman .
 In 1980, Martin et al. demonstrated the ability of
ultrasonically activated K-type files to cut dentin.
 Several studies have shown that ultrasonically or
sonically prepared teeth have significantly cleaner
canals than teeth prepared by hand instruments.
 Despite the multitude of studies conducted on
ultrasonic root canal preparation with ultrasonically
activated files, the current consensus is that this is
not a viable clinical technique

CONCLUSION
 Ultrasonics offers many applications and advantages in clinical endodontics.
 Improved visualization combined with a more conservative approach when selectively removing tooth
structure, particularly in difficult situations in which a specific angulation or tip design permits access to
restricted work areas,.
 Access refinement, location of calcified canals, and removal of separated instruments or posts have
generated more predictable results.
 Better action of irrigation solutions and condensation of gutta-percha have benefited from the use of
US.
 Root end cavity preparation followed by placement of materials in an area that is more often than not
constrained has especially improved the quality of treatment and long-term success. F

Applications of ultrasonics in endodontics

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