Intraosseous Injection of Clindamycin Phosphate Into the Chronic Apical Lesion of Lower Molar-a Case Report

Periapical disease is the result of bacteria, their product, and the host response to them. Early histological studies of diseased periapical tissue have not been able to demonstrate viable bacteria in the lesions studied. Recent reports indicate that many of periapical lesions are indeed infected before and after endodontic treatment. Th e validity and applicability of the microbial delivery overcome many disadvantages that we see with systemic drugs. In this case report we presented a novel approach of managing chronic diff use periapical lesion of lower molar based on specifi c selection of intracanal medicament in combination with direct periapical injection. We used bacterial culturing and antibiotic sensitivity test to select specifi c intracanal medicament, in addition we presented an intraosseous injection technique to locally deliver the selected medicament directly into the periapical lesion. Our fi ndings are encouraging and promising. Th e validity and applicability of the technique needs to be tested in a well controlled clinical trial.


Intraosseous Injection of Clindamycin Phosphate Into the Chronic Apical Lesion of Lower Molara Case Report Introduction
Periapical disease is the result of bacteria, their product, and the host response to them.Early histological studies of diseased periapical tissue have not been able to demonstrate viable bacteria in the lesions studied ().More recent reports indicate that many of these lesions are indeed infected before and after endodontic treatment.In  Wayman studied  cases of periapical lesion ().He cut these lesions in half and examined one half histological and cultured the other half.In only  of  cases could he demonstrate bacteria histologically.However, when the other half lesion was cultured  of  cases were positive.He found  isolates, of which  were strict anaerobes,  were facultative anaerobes and only  were aerobes.Iwu showed that  or  of  periapical granulomas were positive for bacteria when they were cultured.Barkhodar and Desouza () also found bacteria in granulomas and cystis.For many clinicians calcium hydroxide is the most commonly used intracanal medicament, although the eff ectiveness of many other intracanal antimicrobials, such as metronidazole antibacterial gel (), ledermix with tetracycline (), clindamycin-impregnated fi ber (), antibiotic mixtures of ciprofl oxacin, metronidazole, minocycline (), has been proven eff ective.Calcium hydroxide as an intracanal medicament has many advantages (,), but latest evidence demonstrated that enterococci and fungi, commonly found in cases of endodontic failure are highly resistant to calcium hydroxide ().

Aim
Th e primary aim of this case report is to evaluate the effectiveness of using microbial culturing and antibiotic sensitivity testing to select specifi c antimicrobial medicaments to manage endodontic infections.A secondary aim is to evaluate the eff ectiveness of the selected antibiotic as an intracanal medication in combination with intraosseous injection directly into the periapical lesion

CLINICAL PRESENTATION
The patient (age-, gender-female, race-white) came to our office with very slight symptoms in a region of left lower second molar.Clinical and radiographic examination showed coronal microleakage, dental decay, infected pulp space, suppuration with large apical radiolucent lesion.Root canal system was infected as a result of microleakage and consequently dental decay and bacterial flora was transferred from root canal towards periapical tissue.

Specimen collection and microbiological procedure
After clinical and X-ray diagnose of asymptomatic left mandibular second molar with diffuse periapical lesion we did access preparation by sterile burs, restoration and complete removal of soft, carious dentin using sterile burs without water spray.ISO - K-fi les used to scale off dentin debris from the root canal walls.Specimen collected by K-fi les is directly inoculated in liquid thioglycolate broth with paraffi n oil, for further primary and secondary microbiological procedure (Figure .).Th ese procedures included; direct microscopy examination of the specimen, showing size, shape, morphotype, and Gram staining of the present bacteria.During aerobic procedure specimen from thioglycolate broth is inoculated in the blood agar, McConcey and Sabourad (Figure .).For anaerobic procedure another agar plate is necessary with  hemin and placed discs.Anaerobic plates were in pot with Gas-pac system, closed for - hours at  o C in incubator (Figure .).Findings of bacteria around discs and far from discs determined the result of antibiotic susceptibility test.All isolated Streptococcus spp.during microbiological procedure were sensitive to clindamycin.

Conventional endodontic treatment
After completing mechanical instrumentation of two root canals of mandibular second molar we used oxidizing agent,  hydrogen peroxide as root canal irrigant.According to the antimicrobial susceptibility test obtained, as an intracanal medicament a sterile pharmaceutical formulation (with the proper rheological properties) for the root canal treatment was prepared and used.Antimicrobial agent clindamycin phosphate, as an intracanal medicament, was used in concentration of , incorporated in the formulation containing benzyl alcohol, sodium hydroxide, hydroxyethylcellulose, propylene glycol and water for injection.The temporary filling was intact, without leaking, or contamination, sealed hermetically, without exudate, or foul odor from the root canals.Next step was complete obturation of the root canals using cement sealer and guttapercha cone.All procedures were done with respect to ethical standards regulated by Helsinki Declaration.

Th e use of intraosseous injection
In our next appointment patient received regional anesthesia (Figure .).Th e point of intraosseous penetration was attached gingiva, area between the two roots of the second lower molar.We used special equipment, the perforator attached to a slow-speed hand piece was advanced through anesthetized gingiva and bone until penetration through the cancellous bone is experienced (Figure .) (, ).Th e perforator was removed, the short  mm needle was inserted through the perforation into the cancellous space and , ml of clindamycin phosphate solution was delivered slowly (Figure .).

Clinical Outcome
We monitored response to treatment on sequential periapical radiographs using a portable transmission densitometer (Portable densitometer X-Rite , X-Rite Ltd., United Kingdom).We took periapical images at the beginning of the endodontic treatment, during obturation of the root canals two-and six months later.A change in periapical lesion was detected by X-Rite  densitometer showing improvement in periapical healing process.Measured optical density units at the beginning of the endodontic treatment and two months later showed diff erence of , ODU, suggesting improvement in healing process of the affected tissue.Figures ,  and  present periapical images obtained at the beginning of the endodontic treatment, after completed obturation and six months later.

Discussion
In this case report we used bacterial culturing and antibiotic sensitivity to select specifi c intracanal medicament, in addition we presented an intraosseous injection technique to deliver the selected medicament directly into the periapical lesion.Th e combined use of the selected antibiotic as intracanal medicament as well as direct injection into the periapical area enhanced the healing and resolution of the lesion as demonstrated on the sequential periapical radiographs.Th e intervention is completely painless since we had to apply conventional mandibular block, before we used supplemental intraosseus injection technique for local application of clindamycin phosphate.Clindamycin is derived from Strepto- initial (phase I) generation of the clindamycin-aff ected microbes is followed by an ultimate (phase II) generation at the same dose level.Th e dependence of the apparent generation rate constant on drug concentration yields a sigmoidal curve, which is coincident by a potency factor for the phase I and phase II generations of clindamycin-aff ected microbes and suggests a common mechanism of action for both generation phases.

Conclusions
In previously reported cases of conventional endodontic treatment of lower molars with chronic diff use periapical pathology the outcome of treatment has been slow and questionable.In this case report we presented a novel approach of managing these lesions based on specifi c selection of intracanal medicament in combination with direct periapical injection.Our fi ndings are encouraging and promising.Th e validity and applicability of the technique needs to be tested in a well controlled clinical trial.
AMELA LAČEVIĆ ET AL.: INTRAOSSEOUS INJECTION OF CLINDAMYCIN PHOSPHATE INTO THE CHRONIC APICAL LESION OF LOWER MOLAR -A CASE REPORT With assigned form of patient consent we proceeded with the treatment and local antimicrobial drug delivery.
AMELA LAČEVIĆ ET AL.: INTRAOSSEOUS INJECTION OF CLINDAMYCIN PHOSPHATE INTO THE CHRONIC APICAL LESION OF LOWER MOLAR -A CASE REPORT myces lincolnensis ().Th e mechanism of action, like the macrolide class, is inhibition of protein synthesis by binding to the s ribosomal subunit.It has a wide distribution, but does not cross the blood-brain barrier.Th e drug is concentrated in the bone, respiratory tissues, mucus, and saliva.At lower concentrations the drug is bacteriostatic, but bacteriocidal at higher concentration.Resistance is mediated by decreased permeability of the drug into the cell and alteration of binding sites on the s ribosome subunit.Th e spectrum of action is primarily against gram-positive and gram-negative bacteria and anaerobes (especially B. fragilis).Clindamycin phosphate has been shown to be eff ective, among others in the treatment of periodontal abscess, periodontitis, and bone infections when caused by susceptible anaerobic bacteria or susceptible strains of gram-positive bacteria such as Streptococci, Staphylococci and Pneumococci.It possesses both a bacteriostatic and a bactericidal action.Clindamycin-aff ected microbial cultures show biphasic steady-state generation curves.An