Guided Tissue Regeneration in the Healing of Through and Through Lesions

The research process was carried out in the Department Of Conservative Dentistry and Endodontics, Post Graduate Institute of Dental Sciences, Rohtak. Patients with through and through periradicular lesions diagnosed radiographically and clinically were be included in the study.

INCLUSION CRIETERIA :-

1. Patients of age 16 years and above with a clinical \& radiographic diagnosis of through and through periradicular lesion.
2. Negative response to vitality test with radiographic evidence of periapical rediolucencies.
3. Failed previous root canal treatment with purulent discharge and radiographic evidence of periapical pathology.
4. Failed previous surgery with persistent bony lesion.
5. Recurrent episode of purulent discharge and adequate final restoration with no clinical evidence of coronal leakage.

EXCLUSION CRIETERIA :-

1. Unrestorable tooth
2. Fractured /perforated roots
3. Serious medical illness (uncontrolled/poorly controlled diabetes, unstable or life threatening conditions or requiring antibiotic prophylaxis)
4. Smokers
5. Pregnant females and lactating mothers
6. Grade 3 mobile teeth
7. The need for antibiotic prophylaxis prior to dental care

Baseline parameters --

Endodontic evaluation - Pulp sensibility testing was performed with a combination of heat test (heated gutta-percha), cold test (Endo-Frost, Coltene Whale dent) and electric pulp test (Digitestz D626D, Parkell electronics, New York). Teeth not responding to both thermal and electric test were considered non vital.

Radiographic evaluation - Radiographs with paralleling cone technique was taken at baseline and at subsequent appointments at standardized exposure parameters (70kvp, 3.5mAs, and 0.2 seconds).

Clinical Periodontal Evaluation - The following clinical parameters were evaluated at baseline and at subsequent follow up appointments in the test tooth and the contra lateral normal tooth in the same patient.

1. Bleeding on probing - The presence or absence of bleeding following pocket probing were recorded at 6 sites per tooth - mesiobuccal, buccal, distobuccal, mesiolingual, midlingual, distolingual. This assessment was done in full mouth.
2. Probing pocket depth (PPD) - Probing depth was measured as the distance from the gingival margin to the base of the clinical pocket. The probing depth measurements was assessed using a calibrated manual periodontal Williams 0 probe. The probe was inserted with a firm, gentle pressure to the bottom of the pocket and maintained parallel to the vertical axis of the tooth. Measurements were noted at 6 sites per tooth- mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, distolingual. Measurements will be rounded to the nearest whole millimeter.
3. Clinical Attachment Level (CAL) - Clinical Attachment Level was measured as the distance between the base of the clinical pocket and a fixed point on the crown, the cementoenamel junction (CEJ). Measurements were made at 6 sites per tooth- mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, distolingual using wiliiams 0 probe. Measurements were rounded to the nearest whole millimeter. The mean CAL over all examined surfaces were calculated.
4. Gingival marginal level/position from CEJ was measured.Radiographic examination was performed at 0, 3, 6, 9 and 12 months by using Rinn ( XCP instruments, Elgin, IL ) paralleling technique digitized by using Kodak RVG 6000 ( Kodak Digital Radiographic System, Pt Husada Intra Care, Banten, Indonesia ).

SAMPLE SIZE

A total number of 15 patients in each group were selected. Sample size was determined by calculating the difference of success rate between the previous studies of GTR procedures.

1. Test Group: 15 Non vital teeth having through and through periradicular lesion diagnosed clinically and radiographically first treated with conventional endodontic treatment. After follow up of one month if no improvement found clinically and radiographically then apical surgery was carried out using guided tissue regeneration in patients.
2. Control Group: 15 Non vital teeth having through and through periradicular lesion diagnosed clinically and radiographically first treated with conventional endodontic treatment. After follow up of one month if no improvement found clinically and radiographically then apical Surgery was carried out without using guided tissue regeneration.

RANDOMIZATION

Patients were randomly allocated by computer program [ Random Allocation Software (http://www.msaghaei.com/Softwares/dnld/RA.zip) ] into two group. Group I=Collagen membrane group (MG), group II=Control group (CG).

SURGICAL TECHNIQUE:

With the exception of incisions, flap elevation and suturing, all surgical procedures was performed under operating microscope in an operating room under 8x to 16x magnification.

The full thickness (mucoperiosteal flap) was reflected under aseptic condition by the following technique

1. Preoperative mouth rinse with 0.2% chlorhexidine mouthwash was used.
2. Local anaesthesia with lidocaine 2% with epinephrine 1:80,000 was achieved.
3. Buccal intrasulcular incision was given up to the alveolar crest including one tooth mesial to the lesion \& two teeth distal to the lesion, using no.15 blade on handle.
4. Mesial and distal vertical releasing incision were given.
5. Full thickness flap was gently reflected towards the apical area by periosteal elevator. The flap was frequently irrigated with sterile saline to prevent dehydration of periosteal surface.
6. After complete elevation of the flap, debridement (periradicular curettage -enucleation) of the bony lesion was performed. For additional hemostasis during surgery, cotton pellets soaked in 0.1% epinephrine was applied topically as required.
7. A 2-3mm root tip with a 0º to 10º bevel angle was sectioned with cylindrical surgical carbide burs at high speed with sterile water coolant.
8. Root end preparations extending 3mm into the canal space along the long axis of the root was made by using a piezoelectric ultrasonic system with double angled Retrotips coated with Diamond abrasives.
9. Isthmuses, fins, and other significant anatomic irregularities were identified in high magnification and was treated with the ultrasonic instruments. Then the resected root surfaces was stained with methylene blue and were inspected with micromirrors under high magnification of 24x to examine the cleanliness of the root end preparation and detect any other overlooked anatomic details.
10. Root end filling were with mineral trioxide aggregrate (MTA). The adaptation of the filling material to the canal apical walls was confirmed with the aid of an operating microscope at high magnification.
11. After MTA retrofilling in the test group Collagen membrane was applied on buccal side and in the control group nothing was apllied and flap will be closed with 4-0 reverse cutting black silk suture.

RESORBABLE COLLAGEN MEMBRANE:

Bioabsorbable membranes are composed of a wide variety of materials including collagen, polylactic acid, polyurethane, polyglactin 910, acellular dermal matrix, dura mater, chitosan, periosteum, and calcium sulfate. The most common material is collagen, which can be modified through various collagen cross-linking processing techniques to vary the resorption rate.

Numerous studies have shown bioabsorbable membranes to be effective at promoting regeneration in both endodontic and periodontal defects. Because alveolar bone and the periodontal ligament contain collagen, using a collagen membrane might impart some additional advantages for GTR purposes by augmenting its native properties.

Collagen facilitates hemostasis and therefore wound stability by promoting platelet aggregation in addition to promoting fibroblast migration, which could accelerate wound closure. After inspecting the root end filled teeth with microscope and radiographically the defect will be covered with resorbable collage membrane.

Postoperative instructions:

Care must be taken not to over compress the area. patient should rinse with an appropriate antimicrobial agent of the clinician's choice (chlorhexidine glucoanate) twice daily for two weeks. patient should avoid brushing the area for 2 weeks from the surgery date, avoid flossing for 4 weeks from surgery date. following the first 2 weeks from surgery for the next 3 weeks it is recommended to brush the area only with soft brush.

Post - Operative Follow-Up:

Clinical and radiographic examinations were performed every 3, 6 and 12 months by assessing the same parameters as baseline except that PD, CAL, and GMP were not measured until 12 months. Routine examination procedure was used to evaluate any evidence of signs and/or symptoms.

Radiographic evaluations:

Jig radiographs will be taken at 3, 6 and 12th month of follow up. Radiographic healing will be assessed by the criteria as below.

1. Complete healing, defined by re-establishment of the lamina dura
2. Incomplete healing (scar tissue)
3. Uncertain healing
4. Unsatisfactory healing (failure)

Processing Of Data:

Inter and intra observation of data will be analyzed by distribution of data. Categorical data will be analyzed by chi square test. Regression analysis will be done to observe any association between independent and dependent variables. Interobserver/intraobserver reliability with cohen kappa analysis.