Comparative analysis of platelet-rich fibrin, platelet-rich fibrin with hydroxyapatite and platelet-rich fibrin with alendronate in bone regeneration: A cone-beam computed tomography analysis.

AIM: This clinical study was designed to evaluate the volumetric healing of periapical (PA) bone defect after PA surgery, using platelet-rich fibrin (PRF), and its combination with hydroxyapatite and alendronate. SUBJECTS AND METHODS: Twenty male patients of age between 25 and 35 years, having PA pathology (>5 mm on intraoral periapical radiograph (IOPA)) with intraoral sinus opening, were included in this study. Cone-beam computed tomography (CBCT) imaging of all patients was done. Root canal treatment with PA surgery was done. Patients were divided into four groups (5 in each group), on the basis of material placed in PA bone defect. After 1 year, CBCT imaging was done. Linear measurement of maximal dimensions in all three orthogonal planes was done in both pre- and post-CBCT image. These measurements were used to estimate the volume of the lesion healed after 1 year of surgery. STATISTICAL ANALYSIS: Analysis of variance and Post hoc Tukey's test were used for statistical analysis.
RESULTS: Change in volume were significantly different between Group 1 vs Group 3; Group 2 vs Group 3 and Group 3 vs Group 4. The Group Order for change in volume 1 year post surgery Group 3> Group 4 ≈ Group 2> Group 1.
CONCLUSIONS: PA bone healing after surgery is enhanced by placing combination of bone regenerative materials. PRF with hydroxyapatite provides best healing outcomes in comparison to PRF with alendronate or PRF alone. Copyright:

INTRODUCTION

Endodontic surgery is the last resort after failure of nonsurgical endodontic treatment or retreatment. If performed with modern techniques, apicoectomies are associated with 89% success rate among patients undergoing the surgical procedure.[1] Several studies have investigated the prognostic factors associated with endodontic surgical outcomes. The size of the preoperative periapical (PA) lesion is one of them. It has been proposed that large lesions are less likely to heal than smaller ones due to fibroblastic proliferation from periosteum into the osseous defect, resulting in scar formation rather than bony fill.[2] Some studies have reported improved outcomes in both traditional and modern endodontic surgery with smaller lesions – albeit without statistical significant difference.[34]

Bone regeneration in the surgical field can be obtained by use of bone replacement grafts, barrier membranes, and host modulating agents such as platelet-rich plasma. Bone grafts are the most commonly used materials and they have osteogenic, osteoinductive, or osteoconductive properties depending on the nature and processing of the graft. One of such allogenous bone grafts is hydroxyapatite, it plays a major role in repair and regeneration of bony defects.[5]

To enhance new bone formation local application of hormones, growth factors, and plasma derivate has also been advocated. Nevertheless, the extent of their effectiveness is still a query. In the absence of angiogenic factors such as blood clot and platelet-rich fibrin (PRF), bone grafts are not likely to promote PA wound healing. Being host's own biologic product is better space filler than all bone grafting materials. The benefits of using a combination of PRF with bone grafts are improved handling properties and stabilization of graft materials, hemostasis, promoting wound healing, bone growth, and maturation.[67] Studies show that alendronate is effective in reducing alveolar bone resorption after mucoperiosteal flap surgery, but its implication in PA bone healing is still to be investigated.[8]

The use of three-dimensional techniques, such as cone-beam computed tomography (CBCT) for detection of PA osseous lesions, has been described specifically when preparing for surgical endodontics.[9] CBCT has been used for various purposes in endodontics. It enables the detection of endodontic lesions even before demineralization of cortical plates. CBCT can also be used to eliminate the superimposition of anatomical structures and can be useful in identifying processes occurring within the cancellous bone.[10]

The aim of this clinical study was to evaluate the volumetric healing of PA bone defect after PA surgery, using combination of different materials for enhancing bone regeneration with CBCT.

SUBJECTS AND METHODS

Twenty male patients with age between 25 and 35 years and having PA pathology in anterior teeth (>5 mm on IOPA) with intraoral sinus opening were included in this study. Informed consent was obtained from all the patients. All the selected patients were advised for complete blood count, hemoglobin, viral markers (Hepatitis B, HIV), clotting time, bleeding time, and prothrombin time (PT/INR). A preoperative image of concerned tooth of each patient was taken by CBCT at a voxel size of 0.125 mm × 0.125 mm × 0.125 mm.

Oral prophylaxis of each patient was done. Root canal treatment of concerned tooth was completed following standard protocol. The next appointment was given after 24–48 h of obturation. Surgical area was anesthetized by giving nerve block using 2% lignocaine with 1:80000 adrenalin. Crevicular incision accompanied by 2 releasing vertical incision was given. Full thickness flap was raised using periosteal elevator. Adequate cortical bone was removed to obtain access to PA area. Constant irrigation with normal saline was done during bone removal. Curettage was done. Root end was resected up to 3 mm. Root end cavity was prepared and filled with Mineral trioxide aggregate (MTA angelus). After this, patients were divided into four groups (5 in each), on the basis of material placed in PA bone defect.

Group 1-no material

Group 2-PRF

Group 3-PRF with hydroxyapatite

Group 4-PRF with alendronate was placed in bone defect.

Flap was repositioned and sutured [Figure 1]. Medications were prescribed. The patient was recalled after 1 week and suture was removed. Follow-up of all the patients was kept up to 1 year. After 1 year follow-up image of each patient was taken by CBCT.

Figure 1

(a) Preoperative photo (b) flap reflection (c) pathology removal (d) platelet-rich fibrin placement (e) suturing (f) postsuture removal

Volumetric measurement of periapical lesion

Presurgery and after 1 year postsurgery, CBCT images were evaluated by two different evaluators and the linear measurement of maximal dimensions in all three orthogonal planes was done [Figure 2]. Each evaluator was asked to make a measurement from a bone landmark to another bone landmark across the void of the lesion. If the lesion of interest did not demonstrate clearly demarcated bony borders (e.g., cortical plate perforation of the lesion and direct sinus involvement), each evaluator was asked to estimate the lesion boundary by interpolating the lost bony contour. The linear measurements of the lesions were as follows: The maximum diameter in mesiodistal, coronoapical, labiolingual/labiopalatal direction was determined from the largest extent of the lesion. The volume of the lesion was calculated as follows:

Figure 2

Tukey post hoc test of presurgery and 1 year postsurgery volume between groups

where a = Maximum mesiodistal dimension/2, b = Maximum labiopalatal dimension/2, c = Maximum corono apical dimension/2.[11]

RESULTS

For volume measurement, the mean data of the linear measurement of maximal dimensions in all three orthogonal planes that were obtained from two evaluators were used. Analysis of variance (ANOVA) of mean volume of PA lesions in different groups of patient's presurgery shows a statistically significant intergroup difference in mean volume of PA lesions presurgery. (P is 0.031 which is <0.05). However, the Tukey post hoc test of presurgery volume between groups shows that the difference in mean was not significantly different within groups [Table 1a]. For Mean volume of PA lesions in different groups of patients after 1 year of surgery ANOVA does not show any statistically significant (P = 0.349) intergroup difference and difference in mean were also not significant within groups (Tukey post hoc test) as shown in Table 1b. Change in volume in different groups seen 1 year postsurgery showed significant difference (P value = 0.007) [Table 2a]. Tukey post hoc test of change in volume of groups after 1 year of surgery shows that the mean change in volume was significantly different in between Group 1 versus Group 3 (P = 0.007); Group 2 versus Group 3 (P = 0.033) and Group 3 versus Group 4 (P = 0.030) whereas the mean change in volume was not significantly different in between Group 1 versus Group 2; Group 1 versus Group 4 and Group 2 versus Group 4 [Table 2b]. This shows that the addition of PRF (Group 2) did not significantly impact volume change when compared to the non-PRF (Group 1) controls. Combining PRF with hydroxyapatite (Group 3) has shown better healing out comes in groups with PRF combination. Group 4 patients had significantly better results than all other group. PRF with alendronate (Group 4) had results comparable with those of group with PRF alone (Group 2). On the basis of this study, we can say that the PA bone healing after PA surgery is enhanced by placing combination of bone regenerative materials. PRF with hydroxyapatite gave best healing outcomes with faster volume changes than those with PRF with alendronate or with PRF alone. Thus, the final group order for change in volume 1 year postsurgery is Group 3 > Group 4 ≈ Group 2 > Group 1.

Table 1

Tukey post hoc test of pre-surgery and 1 year post surgery volume between groups

1(a) Tukey post hoc test of Pre Surgery Volume between groups
	Mean Difference	P
Group 1 vs Group 2	9.20	1.000
Group 3 vs Group 1	532.70	0.056
Group 4 vs Group 1	35.68	0.998
Group 3 vs Group 2	541.90	0.051
Group 4 vs Group 2	44.87	0.995
Group 3 vs Group 4	497.03	0.079

Table 1b

Tukey post hoc test of 1 year Post Surgery Volume between groups

	Mean Difference	P
Group 1 vs Group 2	71.88	0.971
Group 3 vs Group 1	213.77	0.576
Group 1 vs Group 4	22.58	0.999
Group 3 vs Group 2	285.65	0.338
Group 4 vs Group 2	49.30	0.990
Group 3 vs Group 4	236.35	0.496

P<0.05 is considered significant

Table 2a

Comparison of change in volume in groups one year post surgery

	Mean Difference of Volume (mm3)	SD
Group 1	28.53	±27.28
Group 2	91.21	±111.30
Group 3	347.46	±233.87
Group 4	86.78	±40.44
P	0.007**=Significant, P<0.05 is considered significant

Table 2b

Tukey post hoc test of change in volume of groups one year post surgery

	Mean Difference	P
Group 2 vs Group 1	62.68	0.874
Group 3 vs Group 1	318.93*	0.007*
Group 4 vs Group 1	58.25	0.896
Group 3 vs Group 2	256.25*	0.033*
Group 2 vs Group 4	4.43	1.000
Group 3 vs Group 4	260.68*	0.030*

*Significant; P<0.05 is considered significant

DISCUSSION

CBCT overcomes the limitations of periapical (PA) radiographs. It is capable of detecting lesions that PA radiographs cannot detect, for example, small lesions that are primarily confined to cancellous bone. Recently, CBCT has become the standard imaging modality to assess dental and PA tissues. Images of CBCT visualized lesions allow for the measurement of the area of low density (e.g., PARL), and offer images in three dimensions to accurately estimate the size of the lesion.[11]

Patel et al. suggest that any future clinical research trials should use small field of view (FOV) CBCT scans, and it should be done in such a way so as to assess the healing of lesions that are associated with apical periodontitis.[12] Our study too utilized the small FOV sectional/quadrant scans. Several different methodologies are employed in the evaluation of changes in the size of PA radiolucencies using CBCT. It has been suggested that volumetric measurements of lesions could possibly be the way to assess dimensional change in a lesion since CBCT is capable of allowing assessment of lesions in three dimensions.[11] Some studies have simply asked a yes or no question with regards to the presence of a radiolucency.[13] Other studies have compared preoperative and postoperative CBCT scans and classified the change in size of the lesion into categories (i.e., enlarged PA radiolucency, unchanged PA radiolucency, and reduced PA radiolucency).[1415] Estrella developed a 6-point PA index using CBCT based on Orstavik's similar index for radiographs.[1617]

PA lesions often assume irregular three-dimensional shapes. The implicit advantage of volumetric measurements over two-dimensional linear measurements is the ability of software algorithms, such as DTG, anatomage to accurately approximate the complex geometry of lesions. However, these software-assisted processes require specialized scanning protocols and software and so may not be available to all easily. In circumstances where lesions perforate cortical plate or maxillary sinus, interpolation of lesion boundaries is complicated by the comparable radiodensities of PA lesions and communicating anatomic spaces. The grayscale-based algorithm of DTG may also fail to accurately limit the extent of a lesion, instead including anatomic space to the final volumetric output.

The volumetric measurement of the PA lesion in our study was done in accordance with the study of Fike.[18] It was also similar to the volume estimation done for renal stones.[19]

PA surgery removes diseased soft tissue and with application of different graft material enhances new bone formation at the defective site. The kind of material used to fill the bony defect has found to affect the healing rate at defective site. In our study also, groups varied significantly on parameter of change in volume of PA lesion pre- and post-surgery.

In this study, we found that the addition of PRF did not significantly impact volume change when compared to the non-PRF controls. Our results were contrary to the pilot study done by Angeramea et al. in which they found significant radiographic differences pre- and post-endodontic surgery with the use of PRF.[20] In another study, Monga et al. found PRF to be better than hydroxyapatite for PA bone healing but in this study Group 3 that had PRF with hydroxyapatite performed significantly better than all other groups including PRF.[21] Mixing PRF with graft particles is done as PRF is believed to function as a “biological connector” between the different elements of the graft while acting as a matrix favoring neoangiogenesis, capture of stem cells and migration of osteoprogenitor cells to the center of the graft.[722] In harmony with above concept of mixing PRF with graft materials, our result shows better healing out comes in group with PRF and bone graft combination. This group of patients had significantly better results than all other group.

Alendronate has been used widely in healing of periodontal bone defects but there are no reported studies with its use in endodontic surgery. The promising results of the periodontal studies promoted us to use it for enhancing healing in PA bone defects.[2324] Reddy et al. and Gupta et al. have used alendronate gel as an osteoclast inhibitor in the treatment of human periodontal infrabony defects. They found application of alendronate gel to be significantly better than other options.[2526] In this study, we combined alendronate with PRF since PRF has already proved its utility in healing of PA defect. Denying our anticipations PRF with alendronate group of patients (Group 4) had healing outcome comparable to healing out comes in patient with only PRF placed in bone defects (Group 2). Group 2 versus Group 4 mean difference of change in volume presurgery and postsurgery was 4.43 with a P = 1.0. It implies that there was no added benefit of using alendronate with PRF. The results differed from those seen in periodontal studies.

Postsurgical healing is a dynamic process affected by factors of patient health. The generalizability of this study's results may be limited in patients with systemic health issues. Our study found that at only 1 instance PA lesions showed nearly complete resolution at 12 months following the initiation of treatment. The low incidence of complete resolution, 1 out of 20 lesions, is consistent with findings by van der Borden et al. and Liang et al. and likely attributable to the fact that postoperative CBCTs were taken at 1 year or less.[2728]

Including patients with intraoral sinus opening could have negatively affected the healing outcomes. The generalizability of result of this study is not to be advocated. The results obtained in this study would have been affected by small sample size of each group.

CONCLUSION

On the basis of this study, we can say that the PA bone healing after PA surgery is enhanced by placing combination of bone regenerative materials. PRF with hydroxyapatite gave the best healing outcomes with faster volume changes than those with PRF with alendronate or with PRF alone. Furthermore, based on periodontal studied, there is wide scope of using alendronate in endodontics, but its uses need to be explored and further studies on larger sample size need to be conducted.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.