OBTURATING MATERIALS FOR PRIMARY TEETH

INTRODUCTION

The goal of an any procedure performed in a primary tooth are to maintain arch length, preserve masticatory function, remove acute and chronic infection from tooth or oral cavity.

Primary molar roots are usually curved to allow for the development of the succedaneous tooth. During instrumentation, these curves increase the chance of perforation of the apical portion of the root or the coronal one-third of the canal into the furcation.

Due to the complex morphology of the root canal system in primary teeth, the clinician must rely primarily on chemical cleansing and sterilization and secondarily on mechanical instrumentation during pulpectomy procedure.

And in order to increase the chance of success of the endodontic treatment, substances with antimicrobial properties are frequently used as root canal filling materials in deciduous teeth.

The main objective of endodontic treatment is total elimination of microorganisms from the root canal, and the prevention of subsequent reinfection. This is achieved by careful cleaning and shaping followed by the complete obturation of the canal space.

GOALS OF OBTURATION

1.      Fill the entire root canal completely as closely as possible with suitable obturating materials.

2.      Filling the root canal with a material that will resorb & give way for the eruption of the permanent tooth.

3.      Developmental, anatomical & physiological differences between primary & permanent teeth call for differences in criteria for root.

CRITERIA FOR AN IDEAL PULPECTOMY OBTURANTS

 • Resorbable

• Antiseptic property

 • Non-inflammatory and nonirritating to the underlying permanent tooth germ

• Radio-opacity for visualization on radiographs

• Ease of insertion

 • Ease of removal

VARIOUS ROOT CANAL OBTURATING MATERIALS FOR PRIMARY TEETH

1.      Zinc oxide Eugenol

2.      Calcium hydroxide

3.      Iodoform based pastes

Zinc oxide Eugenol:

Zinc oxide Eugenol is one of the most widely used materials for root canal filling of primary teeth. It was the only materials recommended in the clinical guidelines developed by the American Academy of Pediatric Dentistry (AAPD) untill 2008.

Usually a thin mix of ZOE is made, a consistency in which the material can flow easily.

If thick paste is used, it leads to underfilled canals and to avoid this pressure syringe technique can be used.

ZOE without any catalyst allows a longer working time for filling of canals.

ZOE & combinations:

To improve properties and success rate zinc oxide eugenol in combination with different components like formocresol, formaldehyde and paraformaldehyde and cresol have been tried out, but the addition of these compounds neither increased the success rate nor made the material more resorbable as compared to zinc oxide eugenol alone.

Calcium hydroxide:

Calcium hydroxide is a white odourless crystalline powder. It has low solubility in water and has a high pH of about 12.5.

This material was found to be easy to apply. It resorbs at a slightly faster rate than that of the root. It has no toxic effects on permanent successor.

But it induces internal resorption in primary teeth due to the over stimulation of the undiferentiated mesenchymal cells thus inducing   odontoclast causing resorption of dentin. It has the tendency to get depleted from the canal.

CALEN PASTE:

It is a calcium hydroxide-based paste and exhibits biocompatibility, high antimicrobial activity   and satisfactory clinical, radiographic outcomes & intermediate setting time values.

It showed a lower solubility compared with the other groups.

CTZ PASTE:

CTZ is an antibiotic paste and is a combination of chloramphenicol 500mg, tetracycline 500mg, zinc oxide 1000mg and eugenol 1 drop.

Chloramphenicol has an antimicrobial effect and acts against a large number of aerobic, facultative anaerobe and spirochetes as well as gram +ve and gram –ve microorganisms.

Tetracycline is a broad spectrum antibiotic, which can be bactericidal at high concentration.

ZOE provides analgesic properties and potent antibacterial action.

The advantages of this paste are that the application technique is easy, simple; it has antibacterial effect and also promotes stabilization of bone resorbtion. It does not cause tissue sensitivity and not produce damage to the permanent tooth in development

But this paste leads to the pigmentation of the crown of the treated tooth.

COLLA COTE:

It is a soft white pliable biocompatible sponge obtained from bovine  collagen and can be  applied to moist or bleeding canals. Bleeding from periapex makes obturation difficult, colla cote can be used as an apical stop, or barrier over which obturant can be filled. It is widely used in endodontic therapy. When left inside a  periapical defect, it  gradually resorbs providing a scaffold for bone deposition and growth.

IODOFORM BASED PASTE:

·         WALCOFF PASTE

·         KRI PASTE

·         MAISTO PASTE

·         VITAPEX/METAPEX

·         ENDOFLAS

·         GUEDES-PINTO PASTE

WALCOFF PASTE:

It is a combination of Parachlorophenol , Camphor, Menthol crystals , Eugenol, Zinc oxide, Thymol and Silver powder .

Parachlorophenol is an antiseptic agent. Camphor relieves the pain arising from the near exposure of the pulps of teeth, and also arrests the hemorrhage.

KRI PASTE:

The iodoform in it relieves pain and the camphor arrests hemorrhage and allays the pain of pulp. Parachlorophenol in it disinfects root canal.

KRI paste resorbs rapidly & has no undesirable effects on succedaneous teeth.

MAISTO PASTE:

This paste is known for its comparatively slow rate of resorption when used as an obturating material for primary teeth.

VITAPEX/METAPEX:

It contains Calcium hydroxide and iodoform along with silicone oily base (additive).

This mixture is considered as an ideal root canal filling material for primary tooth, owing to its excellent properties. It has no toxic effects on the permanent successor tooth and has a good antiseptic action.

But if it is pushed beyond the apex, the rate of resorption is faster than the roots, so the rapid elimination of iodoform by the organism leaves behind empty spaces inside the root canal, which may undermine the success of the endodontic therapy.

HERBAL OBTURANTS:

1.      Aloe vera

2.      Tulsi

RETAINED PRIMARY TEETH:  

Retained primary teeth without permanent successor present a unique  challenge to the dentist. Retained deciduous tooth requiring different obturating material that  would not undergo resorption & biocompatible to the retained  primary roots.
So, materials used for situation like this are

• Guttapercha,

 • Mineral Trioxide Aggregate (MTA), and

• Calcium Enriched Mixture (CEM)

                                                              
                    
                                                                                       DR. ANJUSHA SHARDA