Evaluation of lesion sterlisation and tissue repair (LSTR) technique for the treatment of non-vital primary molars present with pathological resorption

Preservation of the primary tooth is the bestmethod of space maintenance for its successor. However, teethwith infected root canals are a common clinical problem. Pediatric dentistsroutinely counter primary teeth showing signs of irreversible pulpitis andpulpal necrosis. The treatment in such cases are conventional approach or teethextraction. Conventional root canal was introduced in early 1932 to save primaryteeth that otherwise would have been extracted. Conventional endodontic therapy is aimed atelimination of microorganisms from the infected root canals and prevention ofreinfection. Premixed calcium hydroxide and iodoform paste is a universally acceptedobturating material for pulpectomy in primary teeth. However, root resorption of primary molars has been found to beaccelerated following pulpectomy with conventional iodoform containing fillingmaterials, leading to their early shedding in comparison with homologous teethwithout endodontic treatment.

The further challenge presented to the pediatricdentist in such conditions where extraction has to be advised and pulpectomycan’t be done in cases of pathological like internal or external rootresorption. Premature loss of primary teeth bring about disturbances likeectopic eruption, altered eruption sequence, crowding, delayed eruption, spaceloss, functional and speech impairment. So, these types can be managedwith  86.4% of success rate with LSTR.

Hoshino of Niigata University School of Dentistryinvented the concept of LSTR therapy in 1990, and popularized by Takushige ,in which a mixture of antibacterial medications was used to sterilise rootcanals. These new medication combinations were discovered to be capable ofsterilising carious lesions as well as infected necrotic pulps of deciduousteeth. Ithas been also demonstrated that having LSTR in resorbed teeth, theperiradicular radiolucent lesions like inflammatory root resorptionsdisappeared or reduced, thus the lesions repaired.

Keeping in view all these things, this techniquewhich is less invasive, less time consuming, and come with primary aim ofelimination of all the microorganism i.e, sterilization of root canal spaceswhich results in good healing. This proves to the beneficial alternative to theconventional root canals which has limitations in various fields like extensiveroot resorption, inadequate bone, and periodontal support, a child belonging topre-cooperative age group, and which is also less time consuming and can bedone in one or two sittings.

As it needs the applicationof a different antibiotic combinations known as "Triple Antibiotic Paste"(TAP) which was developed in major part by Hoshino and colleagues . Eventually, the antibiotic paste and its impact on microorganismspresent in carious dentine and diseased pulp received special attention. Theresults indicated that the microorganisms had been completely removed from theradicular system. TAP is a triple antibiotic that contains ciprofloxacin,metronidazole, and minocycline. TAP can affect bothgram-negative and gram-positive bacteria, and this combination can be effectiveagainst odontogenic microorganisms .

Numerous studies have foundthat minocycline causes tooth discoloration . So, in this vivo studywe are using Double Antibiotic Paste(DAP) as it was found to cause minimum orno tooth discoloration in comparison to minocycline containing TAP

Thus, in this present case control studywe will compare the success of LSTR technique in non vital primary teeth withand without incidence of pathological resorption using DAP with propyleneglycol as vehicle.