Injectable Platelet-Rich Fibrin As An Adjunct To Minimally Invasive Nonsurgical Treatment In Endodontic-Periodontal Lesions: A Randomized Controlled Trial

Inclusion criteria:

Presence of a periodontal-endodontic lesion (EPL without root damage in non-periodontitis patients) according to (Herrera et al., 2018) confirmed by:

• A negative response to pulp sensibility test
• Deep periodontal pockets (≥5 mm) reaching or close to the apex (EPL Grade 2 or 3) according to the classification by (Herrera et al., 2018).
• Absence of root damage

Exclusion criteria:

• Presence of one narrow deep periodontal pocket around the affected tooth (EPL Grade 1)
• Presence of any type of root damage such as root fracture, perforation or resorption
• Presence of crowns or fixed prosthesis
• History of fractured teeth
• Occlusal abnormality
• Periodontal therapy for the last 3 months
• Presence of systemic diseases affecting periodontal healing
• Smoking Interventions

A. Preoperative patient assessment:

1. Patients with endodontic-periodontal lesions criteria will be recruited from Faculty of Dentistry, Cairo University.
2. Patient's general condition of the oral cavity will then be assessed to ensure all the eligibility criteria are met.

B. Diagnostic procedure:

Medical history will be taken first through a series of questions (Appendix 3).

Dental history: Determination of history of pain, trauma, dental cracks, root canal therapy, periodontal mechanical therapy, or orthodontic therapy (Appendix 4).

Clinical Examination:

Determination of tenderness on percussion and occlusion, periodontal condition, pulp and periapical condition, and occlusion (Chen et al., 2024).

• Visual examination: Tooth of interest was inspected using a diagnostic mirror and probe.
• Occlusion

Pulp and periapical condition:

• Tooth vitality: Using ethyl chloride spray . The tooth of interest was examined as well as its contralateral. No response confirmed the presence of a non-vital pulp.
• Tenderness on percussion: Tooth crown tapped vertically and horizontally with the back end of a mirror handle. The contralateral tooth will be tested first as a control.
• Palpation: Firm digital pressure was applied to the mucosa covering the roots and apices. The index finger was used to press the mucosa against the underlying cortical bone.

Periodontal condition:

• Baseline probing depth: measured from the gingival margin to the bottom of the sulcus.

A periodontal probe will be used to take the periodontal clinical measurements from six sites of the teeth of interest (distolingual, mid-lingual, mesiolingual distobuccal, midbuccal and mesiobuccal), (Appendix 2).

• Baseline clinical attachment level: Measured from the CEJ to the bottom of the sulcus. A periodontal probe will be used to take the periodontal clinical measurements from six sites of the teeth of interest (distolingual, mid-lingual, mesiolingual distobuccal, midbuccal and mesiobuccal).
• Tooth mobility: Pressure applied using two mirror handles in a buccolingual direction and given a score using Miller's scoring system (Miller, 1938) as follows:

Grade 1: First noticeable sign of movement greater than normal

Grade 2: Tooth movement of greater than 1 mm in any direction.

Grade 3: Tooth movement of greater than 1 mm in any direction, combined with vertical mobility within the tooth socket.

Radiographic Examination:

• A pre-operative periapical radiograph using intra-oral periapical digital sensor plate. Detection of root fractures, root fissures, root perforations, root resorption, and root development abnormalities will be performed. Based on these results, the tooth is diagnosed as "EPL with root damage" or "EPL without root damage".
• A pre-operative (Baseline) Cone Beam CT will be performed to examine the amount of vertical bone loss and the root condition.

The diagnosis of endodontic-periodontal lesions without root damage is based on the following criteria:

• An abnormal response to pulp sensibility test (compared to sound contralateral or adjacent teeth)
• Deep periodontal pockets (≥5 mm) reaching or close to the apex
• Absence of root damage

If the patient meets the clinical eligibility criteria, an informed consent will be taken from the patient prior to performing any treatment.

The patient will be given a scheduled appointment for all the visits needed to ensure compliance till the end of the trial.

C. Full mouth Professional Mechanical Plaque Removal (PMPR) will be done using an ultrasonic device 1 week before the 2nd endodontic appointment.

D. Endodontic treatment protocol:

First visit:

Non-surgical RCT will be carried out in 2 appointments (Duque et al., 2018; Gill et al., 2023). The tooth will be anaesthetized using inferior alveolar nerve block technique using mepivacaine hydrochloride 2% with 1:100,000 epinephrine . Access cavity will be performed using a round bur and an endo-z bur. The tooth will be properly isolated using rubber dam. Working length will be determined using an apex locator . Intracanal irrigation will be done using 5.25% sodium hypochlorite solution. Cleaning and shaping of the canals will be performed using engine-driven rotary instruments. Canals will be medicated with Calcium hydroxide (Metapaste) . The access cavity will then be sealed with a temporary restoration.

Second visit:

At the second visit calcium hydroxide intracanal medicament will be removed followed by a final rinse protocol using 1 ml EDTA 17% for 1 minute followed by 3 ml 5.25% NaOCl. Canals will then be obturated using a master gutta percha cone and thermoplastisized gutta percha technique and resin-based sealer . The tooth will then be sealed with a final composite restoration.

E. Minimally invasive Non-Surgical Periodontal Treatment (MINST):

MINST (Nibali et al., 2019; Mehta et al., 2024) will follow root canal treatment (Gupta et al., 2015; Evans, 2023; Gill et al., 2023). The therapeutic procedure will be performed under local anesthesia3, using a delicate tip power-driven instrument P3 tip (Guilin Woodpecker, Guilin, China), (Nibali et al., 2015, 2019).

After the MINST procedure, allocation was performed according to the computerized randomization table, and i-PRF was administered into the pockets to the patients allocated to the intervention group.