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 Table of Contents  
ORIGINAL ARTICLE
Year : 2018  |  Volume : 15  |  Issue : 2  |  Page : 70-75

Clinical and radiographic evaluation of platelet-rich fibrin as a pulpotomy agent in primary molars


1 Faculty of Oral and Dental Medicine, Modern Sciences and Arts University, 6th of October City, Egypt
2 Department of Pedodontics, Faculty of Dentistry, Tanta University, Tanta, Egypt
3 Department of Clinical Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt

Date of Submission16-Jun-2017
Date of Acceptance22-Jan-2018
Date of Web Publication25-Jun-2018

Correspondence Address:
Anhar A. A. H. Mostafa
5 Ibn El-Farid Street, Tanta, El-Gharbia Governorate
Egypt
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/tdj.tdj_30_17

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  Abstract 

Objective
This study was carried out to evaluate clinical and radiographic effect of platelet-rich fibrin (PRF) as a pulpotomy agent in primary molars.
Patients and methods
In this randomized-controlled clinical trial, 20 children aged from 4 to 8 years old, each one had at least two lower primary carious molars. Forty selected molars were assigned randomly to one of the two treatment groups: group I (study group): the pulp treated using PRF. Group II (positive control group): the pulp treated using formocresol (FC). All pulpotomized teeth were restored with preformed stainless steel crowns. Then all the patients were evaluated every 3 months over a period of 12 months with clinical and radiographic examination.
Results
At the end of this study, the clinical success rate of the PRF group showed 89.5%, whereas FC group showed 94.7%. In contrast, the radiographic success results of the PRF group showed (78.9%), whereas FC group displayed success rate of 84.1%. There was no statistically significant differences between the two groups regarding to their clinical performance (P = 0.547) and radiographic performance (P = 0.676).
Conclusion
PRF is considered an acceptable pulpotomy agent that can be used as an alternative to FC.

Keywords: platelet-rich fibrin, primary molars, pulpotomy


How to cite this article:
Mostafa AA, El Hosary AM, Zahra MK. Clinical and radiographic evaluation of platelet-rich fibrin as a pulpotomy agent in primary molars. Tanta Dent J 2018;15:70-5

How to cite this URL:
Mostafa AA, El Hosary AM, Zahra MK. Clinical and radiographic evaluation of platelet-rich fibrin as a pulpotomy agent in primary molars. Tanta Dent J [serial online] 2018 [cited 2018 Jul 18];15:70-5. Available from: http://www.tmj.eg.net/text.asp?2018/15/2/70/235133


  Introduction Top


Pediatric endodontics is more controversial than any field in pediatric dentistry [1]. Preservation of the remaining vital portion of a cariously exposed pulpal tissue in primary teeth, where the demand is to keep a functioning tooth in site, was one of the most frequent problems in pediatric dentistry [2].

To solve this problem, pulpotomy therapy was introduced, developed, and classified according to the treatment objectives [3]. Pulpotomy involves amputation of the coronal portion of the affected dental pulp. The ideal pulp dressing material after pulpotomy should leave radicular pulp vital, healthy, and enclosed within an odontoblastic-lined dentine chamber [4]. This is the reason why pulp therapy in dentistry, particularly the pulpotomy procedure in pediatric dentistry, has remained a controversial issue.

Several materials have been using for capping the radicular pulp after pulpotomy, these included formocresol (FC) [5], glutaraldehyde [6], ferric sulfate [7], laser [8], and mineral trioxide aggregate [9]. However, none of them had met the same degree of effectiveness and success rate as FC, possible hazards of FC (cytotoxicity, carcinogenicity, immunologic, biochemical, mutagenic, and teratogenic changes) in the host have been reported [10]. Moreover, it produced enamel defects in the permanent successors [11]. An effective pulpotomy medicament should show clinical and radiographic success as well as compatibility between pulp and surrounding tissue physiologically [12].

In this regard, the demand for natural medicament to replace FC as a pulp dressing material became imperative. Inspite of the growing improvements in material sciences, researches still document the mild to moderate cytotoxic effects of various biomaterials used for pulpotomies, when they are placed in direct contact with the pulp tissue [13].

Hence, there is a constant need for biologically based autologous materials to neutralize the side effects, if any, due to synthetic based biomaterials, to reduce the pulpal inflammation and to promote faster healing [13]. Platelet-rich fibrin (PRF) is a second generation platelet concentrate introduced by Choukroun et al. [14]. It is strictly autologous and helps to release the growth factors necessary for the regeneration of dentin pulp complex thereby accelerating the healing process.

This study was carried out to evaluate clinical and radiographic effect of PRF as a pulpotomy agent in primary molars.


  Patients and Methods Top


Study design

This study was conducted as randomized-controlled clinical trial.

Study setting

The study was carried out at Pedodontic Clinic, Faculty of Dentistry, Tanta University.

Study sample

This study was carried out on 20 healthy children of both sexes aged from 4 to 8 years old selected from patients attending outpatient clinic of Pedodontic Department, Faculty of Dentistry, Tanta University. Each child had at least two lower primary carious molars ( first and/or second) indicated for vital pulpotomy.

Inclusion criteria

  • Healthy children free from any systemic diseases
  • Bilateral carious lower primary molars with vital pulp exposure
  • Teeth that could be restored with proper restorations.


Exclusion criteria

  • Patients exhibiting clinical signs and symptoms of pulp degeneration such as; spontaneous throbbing pain, tenderness to percussion, tooth mobility, soft-tissue swelling, and fistula or sinus tract
  • Radiographic evidence of; a widened periodontal ligament space, internal or external resorption, intraradicular bone loss, or periapical pathosis, pathological root resorption.


Approval for this research was obtained from Faculty of Dentistry, Tanta University Research Ethics Committee. The purpose of the present study was explained to children's parents and informed consents were obtained according to the guidelines on human research published by the research Ethics committee at Faculty of Dentistry, Tanta University. Each child was coded on a special sheet, bearing the patient's name, age, medical and dental history, date of treatment, and successive follow-up records.

Materials

The materials used in this study were:

  • FC (Buckley's Formocresol; Sultan Healthcare, Englewood, New Jersey, USA): containing 19% formaldehyde, 35% cresol, 17.5% glycerin
  • Intermediate restorative material (DENTSUPLY Detrey GmbH, Konstanz, Germany): reinforced zinc oxide–eugenol composed of powder contains: zinc oxide, polymethacrylate, and liquid contains: Eugenol
  • Glass ionomer cement (Prevest DenPro Micron Luting)
  • 3M Stainless steel crowns (3M ESPE, Landsberg am Lech, Germany).


Methods

Clinical examination was done, preoperative standardized periapical radiographs were taken to assess the tooth condition and to ensure proper case selection.

Preparation of platelet-rich fibrin

It was accomplished according to the technique of Choukroun et al. [14]. The required amount of blood sample (1 ml) was withdrawn from the child's forearm and transferred in a test tube without adding anticoagulant.

The blood sample obtained was immediately centrifuged using a centrifuge (Model 800D, China) at 3000 rpm for 10 min. After centrifuging, the following three layers were naturally formed in the tube: platelet-poor plasma at the surface, PRF clot in the middle, and red blood cells at the bottom.

Sterile tweezers were inserted into the tube to gently grab and remove the fibrin clot. The PRF clot was squeezed between the sterile dry gauze to drive out the fluids trapped in the fibrin matrix and to obtain a highly resistant autologous fibrin membrane. This membrane has been put on sterile glass slap and cut into two equal halves by using scalpel blade size #15 with handle size #3.

Clinical procedures

After pulpotomy procedure hemostasis was apparent; otherwise if pulpal bleeding persists the case would be excluded from the study.

Group assignment

Forty selected molars were assigned randomly to one of the two treatment groups:

  • Group I (study group): the pulp treated using PRF
  • Group II (positive control group): the pulp treated using FC.


For group I, after achieving hemostasis, each half of the freshly prepared PRF membrane was placed over the amputated pulp stumps by using sterile tweezers.

For group II, after achieving hemostasis, a sterile cotton pellet dipped and squeezed in one-fifth concentration of Buckley's FC was placed over the amputated pulp stumps for 5 min. When the pellet was removed the amputated site appeared dark red to brown in color, which indicates fixation of the remaining coronal radicular pulp tissue.

In all treated molars the pulp chamber was covered with a thick mix of intermediate restorative material then the teeth were prepared to receive an appropriate stainless steel crowns as a final restoration. Occlusion and adaptation were checked and crowns cemented with glass ionomer cement. [Figure 1].
Figure 1: pulpotomy procedure for both groups.

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Clinical evaluation

Clinical evaluation was recorded according to the success criteria reported by Neamatollahi and Tajik [15] as follows:

  • Absence of pain either spontaneous or induced by cold, hot, or percussive stimuli
  • No abscess or fistula
  • No soft-tissue swelling and/or abnormal tooth mobility.


Radiographic evaluation

Radiographic evaluation was recorded according to success criteria reported by Neamatollahi and Tajik [15] as follows:

  • Normal periodontal ligament space on the periapical radiograph
  • Absence of internal and/or external root resorption
  • No signs of any radiolucencies in the furcation and/or the periapical area.


The patients were recalled and evaluated every 3 months over a period of 12 months with clinical and radiographic examination. Success or failure of the pulpotomy medicaments was dependent on the clinical and radiographic findings in each recall visit.

Statistical analysis

Data were analyzed using statistical program for social science (version 20; IBM Corp., Armonk, New York, USA). Quantitative data were expressed as frequency and percentage. χ2-test of significance was used to compare the proportions between two groups as regards quantitative parameters.


  Results Top


In this study, a total of 40 pulpotomized mandibular primary molars were performed on 20 children. All cases were available and presented for clinical and radiographic evaluations after 3, 6, 9, and 12 months except for one case that has been lost after 3 months. (Drop-out of one case due to failure to return for follow-up.)

Clinical success and failure rates of the two groups

PRF group showed 100% clinical success rate at 3 and 6 months. At 9 months it revealed 94.7%, whereas decreased to 89.5% at 12 months. In FC group, the clinical success rate was 100% at 3 months, then became 94.7% at 6, 9, and 12 months. Throughout the different follow-up periods, there were no significant differences between the two groups regarding to their clinical success rates [Table 1].
Table 1: Clinical success and failure rates of the two groups at different follow-up periods

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Radiographic success and failure rates of the two groups

PRF group showed lower radiographic success rate than FC group with 100% at 3 months, 94.7% at 6 months, 84.1% at 9 months and 78.9% at 12 months. The FC group showed radiographic success rates of 95, 89.5, 84.1, and 84.1%, respectively along the different follow-up periods. There were no significant differences between the two groups regarding to their radiographic success rates throughout the different follow-up periods [Table 2] and [Figure 2] and [Figure 3].
Table 2: Radiographic success and failure rates of the two groups at different follow-up periods

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Figure 2: Periapical radiographs showing PRF pulpotomy on lower right E & F.C pulpotomy on lower left E.

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Figure 3: Periapical radiograph showing a) Internal root resorption after 6 months of PRF pulpotomy in a lower first primary molar. b) Intra-radicular bone loss after 3 months of FC pulpotomy in a lower second primary molar.

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  Discussion Top


Recent approaches to pulpal injury treatment have essentially followed two paths. One has continued the traditional path and has sought to find improved synthetic materials that provide better seals. The other path has taken a biologic approach and explores the molecular and cellular basis for pulp tissue regeneration with the hope of identifying a biologically based strategy for the treatment of pulp exposures [16].

PRF used in the present study as pulp dressing material for primary teeth because it is strictly autologous matrix containing a large quantity of platelets and cytokines [17], leukocytes, and small lymphocytes entrapped within the PRF membrane are particularly efficient in the regulation of inflammatory and infectious phenomena [18]. Growth factors play a pivotal role in tissue formation and repair in the dentine–pulp complex. They are responsible for tooth morphogenesis, differentiation, and recapitulation of these processes allows tissue regeneration [19].

Although FC selected as the control group, as it is still considered the gold standard in primary teeth pulp therapy due to its ease in use and excellent clinical success. However, the safety of using aldehyde-based products in pediatric dentistry becomes questionable [20].

Because there are no studies to date reporting the use of PRF on pulpotomized primary teeth, the results of the present study were compared with studies using the regenerative materials of the same mode of action. Platelet-rich plasma (PRP) is a first-generation platelet concentrate obtained by two-steps centrifugation method. It contains a concentrated suspension of the growth factors found in platelets similar to that of PRF.

The clinical findings of the PRF group after 3 months follow-up, are coinciding with a study done by Somani et al. [21], who studied the effect of PRP on pulpotomy of primary teeth. Clinical examinations revealed absence of pain and mobility, as all teeth were asymptomatic after 3 months evaluation and PRP showed a 100% success rate. However, clinical success of PRF in the present study may be attributed to its biocompatibility [22], supportive effect on immune system and it helps in hemostasis [18].

The radiographic failure rates (21.1%) observed in PRF group and 15.9% in FC group in the form of internal resorption and periapical radiolucency may be attributed to several factors such as; extreme heat produced during cutting of dentin, chronic inflammation of the pulp following caries perpetuated by bacterial factors [23] and the vascular changes in the pulp may produce hyperemia, causing an increased oxygen tension resulting in low pH levels, thus attracting numerous macrophages to the site, thereby piloting the onset of resorptive process [24].

The present results do not support the results of Huang et al. [25], who stated that PRF can increase dental pulp cells proliferation and differentiation, suggesting potential applications of PRF as a biological molecule to promote the regeneration of lost or injured dental pulp tissues and stimulate reparative dentinogenesis. As in the present study, there is no periapical radiograph has shown any areas of radio-opacities which mean the formation of either calcific dentin bridge or pulp canal calcification in any of the treated pulpotomized primary teeth with PRF along the different follow-up periods.

Actually, the observed limitations of PRF membrane may be attributed to the structural characteristics of the PRF membrane including; the size of the membrane, dissolution rate and the technique of preparation. The type of the restoration above the PRF membrane may also affect the prognosis of the pulp therapy.

Regarding to FC evaluation in the present study, it was found that FC showed clinical and radiographic success rates (94.7 and 84.1%, respectively) after 12 months follow-up. Clinically, these findings nearly agreed with previous studies showed 91.3% by Srinivasan and Jayanthi [26], 92.1% by Al-Mutairi and Bawazir [27], and 96.3% by Fei et al. [12]. Although for the radiographic results, these findings agreed with the results obtained by Fei et al. [12] (81%), Olatosi et al. [28] (81%), and Godhi et al. [29] (88%). These agreements may be related to FC antiseptic and fixative qualities.

Internal root resorption and intraradicular bone loss were observed as common radiographic findings in FC group in the current study. These findings were in accordance with different studies [30],[31], they contributed the radiographic changes after FC pulpotomy to different factors such as the possibility of penetration of formaldehyde through the pulpal floor with subsequent damage to the intraradicular area. Although internal resorption may be due to a traumatic cutting technique or the presence of an extrapulpal blood clot that would cause chronic inflammation.

In agreement with Dohan Ehrenfest et al. [32], the fact that the PRF clot should be used immediately after preparation, as it will shrink resulting in dehydration and altering its structural integrity. Dehydration also results in decreasing growth factor content in PRF and leukocyte viability leading to change in its biologic properties. Therefore, sticking onto a standard protocol for PRF preparation is very important.

Other clinical trials [33],[34] on PRF supported these suggestions as well, providing evidence for a clearly biological effect by PRF, despite the limitations of its use.

The present study reported no statistically significant difference between clinical outcomes (P = 0.547) and radiographic outcomes (P = 0.676) between the two groups. The explanation may be taken on the basis that the clinical and radiographic parameters may not provide information about the histological criteria. A histological study may better explain the influence of these two pulpotomy agents on pulpal healing.


  Conclusion Top


The two tested materials PRF and FC were performed clinically better than the radiographic findings and PRF group was observed to give near results to FC group. So, PRF is considered an acceptable pulpotomy agent that can be used as an alternative to FC.

Recommendations

  • Further long term studies are recommended with larger sample size for PRF investigation to ensure its favorable outcome and to reach sound conclusions
  • Further histopathological studies are required to assess the success rate of PRF.


Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
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