Indian Journal of Oral Health and Research

: 2020  |  Volume : 6  |  Issue : 1  |  Page : 26--28

Efficacy of lesion sterilization and tissue repair using different materials in primary molars: A case series

Astha Jaikaria, Seema Thakur, Amolkumar Lokade 
 Department of Pedodontics and Preventive Dentistry, HP Government Dental College and Hospital, Shimla, Himachal Pradesh, India

Correspondence Address:
Dr. Astha Jaikaria
Room Number 310, Third Floor, Department of Pedodontics and Preventive Dentistry, HP Government Dental College and Hospital, IGMC, Shimla - 171 001, Himachal Pradesh


The concept of lesion sterilization and tissue repair (LSTR) therapy involves the use of a triple antibiotic mixture in a suitable vehicle, which is used to disinfect the root canal systems. This series highlights three cases where pulp therapy using modified 3 Mix antibiotic paste and chloramphenicol, tetracycline, and zinc oxide-eugenol paste was attempted in primary molars with or without pulpal and periapical involvement. Successful clinical and radiographic assessment after 6 months advocates LSTR therapy as an alternative option to conventional pulp therapy.

How to cite this article:
Jaikaria A, Thakur S, Lokade A. Efficacy of lesion sterilization and tissue repair using different materials in primary molars: A case series.Indian J Oral Health Res 2020;6:26-28

How to cite this URL:
Jaikaria A, Thakur S, Lokade A. Efficacy of lesion sterilization and tissue repair using different materials in primary molars: A case series. Indian J Oral Health Res [serial online] 2020 [cited 2022 Dec 4 ];6:26-28
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Pulp therapy has been suggested since 1932 as a method for maintaining primary teeth, which would otherwise be lost.[1] Length of pulpectomy and associated complications make it controversial for a number of reasons mainly being the perceived difficulty of pediatric behavior management, uncertain root canal filling material effects, and instrumentation on the succedaneous teeth. Anatomic situations like the often complicated curved and tortuous shape of root canals and the closeness of the advancing tooth buds also add to the difficulty.[2] Another limitation is the apparent connection between the coronal floor with the intraradicular area[3] with the presence of multiple accessory canals and ramifications as well as the difficulty in obtaining hermetic seal due to the lack of apical closure following physiologic root resorption.[4]

Lesion sterilization and tissue repair (LSTR) therapy is a relatively new biologic approach in the treatment of carious lesions with or without pulpal and periapical involvement using a mixture of three broad-spectrum antibiotics, namely metronidazole, ciprofloxacin, and minocycline (3 Mix).[5],[6],[7] The rationale of LSTR is that a mixture of three antibiotics (3 Mix) can sterilize necrotic pulps and infected root dentin of primary teeth. Repair of damaged tissues can be expected if lesions are disinfected. In the primary dentition, LSTR has shown a high rate of clinical success as a substitute for pulpectomy.[8],[9]

 Case Reports

The case series consists of patients in the age group of 4–8 years in which ethical approval from the Institutional Ethical Committee and consent from the parents/guardians were obtained. The criteria for the selection of teeth include first and second primary molars (maxillary and mandibular) showing the signs and symptoms indicating pulpectomy. Patients with any systemic illness or with a previous history of allergy to the antibiotics used in the study were excluded from the study. Radiographic success of the three cases was evaluated after an interval of 6 months.

Case 1

Only the coronal pulp was removed and the pulp chamber half-filled with modified 3 Mix antibiotic paste using chemotherapeutic agents used were ornidazole tablets 500 mg (Ornida, Aristo Pharmaceuticals, India), ciprofloxacin tablets 500 mg (Ciplox®, Alchemist Ltd., India), and cefaclor tablets 250 mg (Distaclor™ DT, Baroque pharmaceuticals, India). After the removal of enteric coating of tablets with the help of Bard-Parker blade, the drugs were pulverized into a fine powder using sterilized mortar pestle. The powered drugs were kept separately in amber-colored air-tight containers. The fine powder was used up within a month. 3 Mix-Macrogol and Propylene glycol (MP) paste was freshly prepared for each use. The same amount of each powdered drug (1:1:1) was mixed to form modified 3 Mix powder. One part of propylene glycol (P) and the same volume of macrogol (M) were mixed to make MP. For standard preparation, one part of MP and seven parts of modified 3 Mix powder were mixed, placed in the pulp chamber and sealed with glass-ionomer cement (GIC) in the same visit and reinforced with stainless crown after 7 days [Figure 1].{Figure 1}

Case 2

Similar clinical procedure as Case 1 was followed with the difference being that the canals orifices were enlarged using round bur to form medication cavity with diameter 1 mm and depth 2 mm at root canal orifice acting as receptacle for medication and the accessible radicular pulp was extripated using H-files and filled with 3 Mix-MP paste, the cavity was filled with GIC restoration in the same visit. After 7 days, the tooth was then restored with a stainless steel crown, as shown in [Figure 2].{Figure 2}

Case 3

The same clinical procedure followed as Case 1, but the pulp chamber is filled with chloramphenicol, tetracycline, and zinc oxide-eugenol (CTZ) paste. Agents used were tetracycline (Tetracycline capsules, Resteclin® Abbott Healthcare Pvt. Ltd.) and chloramphenicol (Chloramphenicol capsule, 500 mg Paraxin® Abbott Healthcare Pvt. Ltd.). After the removal of enteric coating of capsules, the drugs are pulverized one by one into a fine powder using sterilized mortar pestle. The same amount of both powdered drugs along with two parts of zinc oxide powder (Zinc oxide powder, Dental Products of India [DPI], Mumbai, India) and drop of eugenol (DPI, Mumbai, India) were dispensed on clean glass slab and mixed to form CTZ paste. The ratio of tetracycline: chloramphenicol: zinc oxide mixture was 1:1:2 along with one drop of eugenol [Figure 3].{Figure 3}

All three cases showed good clinical and radiographic results with no signs of postoperative inflammation, internal resorption, or increase in radiolucency after 6-month follow-up.


Premixed calcium hydroxide and iodoform pastes have better resorbability and disinfectant properties than zinc oxide eugenol (ZOE). However, there is no high-quality evidence to support the superiority of these materials over ZOE at present.[10] Sato et al.[7] reported the bactericidal efficacy of tri-antibiotic mixture (100 μg/ml each) against bacteria isolated from the carious dentin and infected pulp tissues of human deciduous teeth. Tetracycline causes the inhibition of collagenases and matrix metalloproteinases[11] and an increase in the level of interleukin-ten, which is an anti-inflammatory cytokine.[12]

Cruz et al.[13] showed that the addition of propylene glycol and macrogol (MP) as a carrier vehicle greatly improved the penetration ability of these medications. Drug history forms an important part of the treatment and should be avoided if a history of allergy to any of the antibiotics is reported by the patient.

There is, however, a need for investigations to understand the reaction of periapical tissues to drugs as well as the amount of drug absorption into the systemic circulation.


Both materials have shown clinically as well as radiographically comparable and acceptable results.

The above case series thus shows that the modified 3 Mix-MP and CTZ LSTR therapies hold promising potential to be used as an effective alternative option in the endodontic treatment of primary teeth.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardians of all patients have given their consent for images and other clinical information to be reported in the journal. The guardians understand that their names and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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