Induction of Periodontitis via a Combination of Ligature and Lipopolysaccharide Injection in a Rat Model

Summary

In this study, a rat model of induction of periodontitis is presented via a combination of retentive ligature and repetitive injections of lipopolysaccharide derived from Porphyromonas gingivalis, over 14 days around the first maxillary molars. The ligation and LPS injection techniques were effective in inducing peridontitis, resulting in alveolar bone loss and inflammation.

Abstract

Periodontitis (PD) is a highly prevalent, chronic immune-inflammatory disease of the periodontium, that results in a loss of gingival soft tissue, periodontal ligament, cementum, and alveolar bone. In this study, a simple method of PD induction in rats is described. We provide detailed instructions for placement of the ligature model around the first maxillary molars (M1) and a combination of injections of lipopolysaccharide (LPS), derived from Porphyromonas gingivalis at the mesio-palatal side of the M1. The induction of periodontitis was maintained for 14 days, promoting the accumulation of bacteria biofilm and inflammation. To validate the animal model, IL-1β, a key inflammatory mediator, was determined by an immunoassay in the gingival crevicular fluid (GCF), and alveolar bone loss was calculated using cone beam computed tomography (CBCT). This technique was effective in promoting gingiva recession, alveolar bone loss, and an increase in IL-1β levels in the GCF at the end of the experimental procedure after 14 days. This method was effective in inducing PD, thus being able to be used in studies on disease progression mechanisms and future possible treatments.

Introduction

Periodontitis (PD) is the sixth most prevalent public health condition worldwide, affecting approximately 11% of the total population, being an advanced, irreversible, and destructive form of periodontal disease^1,2. PD is an inflammatory process that affects the gingival and periodontal tissues, which results in gingiva recession, apical migration of the junctional epithelium with pocket development, and the loss of alveolar bone³. Furthermore, PD is associated with several systemic diseases, including cardiovascular disease, obesity, diabetes, and rheumatoid arthritis, for which enviro....

Protocol

NOTE: The experimental protocol of the study was approved by the Ethical Committee of Animal Experimentation of the Balearic Islands Health Research Institute (CEEA-UIB; reference number 163/03/21).

1. Animal anesthesia and procedure preparation

1. Sterilize all surgical instruments (aluminium mouth gags, dental explorer, diamond lance, surgical scissors, microsurgical pliers, a micro needle holder, a hollenback carver, a periosteal microsurgical elevator, and microsu.......

Discussion

This method describes the induction of PD in rats following a combined technique of Pg-LPS injections and ligature placement around the M1, revealing that significant changes in the periodontal tissues and alveolar bone could be induced in 14 days following this method.

During this procedure, attention to different critical steps must be provided. During animal anesthesia and procedure preparation, assessing the proper anesthesia during the surgical process is critical for its success.......

Materials

Name	Company	Catalog Number	Comments
Adsorbent paper point nº30	Proclinc	8187
Aprotinin	Sigma-Aldrich	A1153
Atipamezole	Dechra	573751.5	Revanzol 5 mg/mL
Braided silk ligature (5/0)	Laboratorio Arago Sl	613112
Buprenorphine	Richter pharma	578816.6	Bupaq 0.3 mg/mL
Cone-beam computed tomography (CBCT) Scanner	MyRay	hyperion X9	Model Hyperion X9
CTAn software	SkyScan		Version 1.13.4.0
Dental explorer	Proclinc	99743
Diamond lance-shaped bur	Dentaltix	IT21517
Food maintenance diet	Sodispain research	ROD14
Heated surgical platform	PetSavers
Hollenback carver	Hu-FRIEDY	HF45234
Hypodermic needle	BD	300600	25G X 5/8” - 0,5 X 16 MM
Isoflurane	Karizoo		Isoflutek 1000mg/g
Ketamine	Dechra	581140.6	Anesketin 100 mg/mL
Lipopolysaccharide  derived from P.Gingivalis	InvivoGen	TLRL-PGLPS
Methanol	Fisher Scientific	M/4000/PB08
Micro needle holter	Fehling Surgical Instruments	KOT-6
Microsurgical pliers	KLS Martin	12-384-06-07
microsurgical scissors	S&T microsurgical instruments	SDC-15 RV
Monitor iMEC 8 Vet	Mindray
Multiplex bead immunoassay	Procartaplex, Thermo fisher Scientific	PPX-05
Paraformaldehyde (PFA)	Sigma-Aldrich	8187151000
Periosteal microsurgical elevator	Dentaltix	CU19112468
Phenylmethylsulfonylfluoride (PMSF)	Roche	10837091001
Phosphate Buffer Solution (PBS)	Capricorn Scientific	PBS-1A
PhosSTOP	Roche	4906845001	Commercial phosphatase inhibitor tablet
Plastic vial	SPL Lifesciencies	60015	1.5mL
Saline	Cinfa	204024.3
Stereo Microscope	Zeiss		Model SteREO Discovery.V12
Surgical loupes led light	Zeiss
Surgical scissors	Zepf Surgical	08-1701-17
Syringe	BD plastipak	303172	1mL
Veterinary dental micromotor	Eickemeyer	174028
Xylazine	Calier	20102-003	Xilagesic 20 mg/mL