Bioactive Glass and Platelet Rich Fibrin in Intrabony Defects

INTRODUCTION

Periodontitis is an infectious disease that causes destruction of the attachment apparatus.[1].The mainstay aim of periodontal treatment is the regeneration of the lost attachment apparatus of the teeth. Variety of treatment modalities are available for periodontal regenerative therapy including bone grafts, bone substitutes, Guided Tissue Regeneration, growth factors, application of tissue engineering or the combination of two or more of the above listed approaches. [2] Alloplasts, may be an effective alternative to allograft and xenografts as there is no risk of disease transmission and the supply is unlimited.[3] The Bioactive glass promotes osteogenesis by adsorption and concentrations of protein utilized by osteoblast to form a mineralized extracellular matrix. [4] The advantage of the putty form of bioactive glass is the glycerine and polyethylene glycol which makes the glass particle coherent and thus enhancing handling characteristics and minimal migration of graft particles from the defect site. [5] Histological evaluation of material has shown that the particulate tends to retard the down growth of epithelial tissue. [6,7,8,9] Growth factors play a pivotal role in periodontal regeneration. Platelet Rich Fibrin is believed to release polypeptide growth factors, such as transforming growth factors-ß, platelet derived growth factors, vascular endothelial growth factors and matrix glycoproteins (such as thrombospondin -1) into the surgical wound in a sustained fashion for at least 7 days as shown in vitro. [10] Thus, given the unique graft with osteoconductive, osteoinductive and osteostimulative properties and properties of autologous PRF, application of combination approach was attempted for the assessment of their additional benefits to the healing mechanisms and periodontal regeneration in intrabony defects.

Materials and methods Patient Selection This randomized control trial was carried out in the Department of Periodontics and Oral Implantology, Santosh Dental College and Hospital, Santosh University, Ghaziabad. Ten patients suffering chronic localized periodontitis aged between 20 -50 years (7 males and 3 females) with 10 pairs of contalateral intraosseous defects (n=20) comprised the study population. A total of 20 bone defects (10 pairs) were decided by the statisticion to be of statistical strength. Convenient sampling design was used for the enrolment of study patients. Ethical approval was taken from the institutional ethical committee The patients were explained in detail about the procedure and a written informed consent was taken. The intrabony defects were diagnosed clinically with moderate to deep periodontal pockets > or = 5mm and with clinical and radiographic evidence of vertical/angular osseous defects. [3] Patients with systemic diseases, on anticoagulants, those with habit of smoking and alcohol, with known history of allergy to graft material and who have undergone periodontal surgical treatment for chronic periodontitis within twelve months for the same defects were excluded from the study.

PRESURGICAL THERAPY Patients underwent phase I therapy. The selected defects were evaluated after 2 weeks, and persistent pockets > or = 5mm and patients with clinical radiographic evidence of angular osseous defects were scheduled for surgery.

Clinical Parameters :

Oral hygiene status was recorded using the gingival index of Loe \& Sillness,[11];

with score 0 indicating absence of inflammation and score 3 indicating severe

inflammation and plaque index of Silness \& Loe. [12]

Probing pocket depth and Clinical attachment level were recorded at baseline on the

day of surgery, 3, 6 and 9 months intervals using UNC-15 probe and customized

acrylic occlusal stents grooved in the area of defect to provide reproducible insertion

axis-

The following measurements were recorded with customized

acrylic stent:

• Fixed reference point (FRP) to the base of pocket (BP)
• Fixed reference point (FRP) to the cemento-enamel junction (CEJ)
• Fixed reference point (FRP) to the gingival margin (GM)

PPD and CAL were calculated from these probing measurements as:

• PPD = (FRP to BP) - (FRP to GM)
• CAL= (FRP to BP) - (FRP to CEJ)

Radiographic measurements: Standardized intra-oral periapical radiographs of the defects were taken using a paralleling technique.[13]

Amount of defect fill: Defects were measured from the fixed reference point (distance between the cemento-enamel junction to the radiographic base of the bone defect ) with the help of 1.1 mm grid and the following radiographic features were recorded on the day of surgery, 3, 6 and 9 months intervals.