Platelet Rich Fibrin: A Novel Approach for Osseous Regeneration

 

To evaluate the efficacy of autologous platelet rich fibrin in soft tissue healing and bone regeneration in mandibular third molar extraction sockets.

Method

The study was conducted in 20 patients visiting in outpatient department of Oral and Maxillofacial Surgery, requiring extraction of bilateral mandibular third molar, following extraction platelet rich fibrin (PRF) was placed in one extraction sockets, the other socket was studied as the control sites with no PRF. The patient were assessed for post operative pain, soft tissue healing and trabecular pattern in healing bone. Radiological assessment of the extraction site was done for period of 3 months to evaluate the change in bone density.

Results

Pain was less in study side compare to control site soft tissue was healing was better in study site. Evaluation of trabecular bone formation started earlier in PRF site compare to control site. The evaluation of bone density by radiological assessment showed the grey level value calculated after 3 months at the PRF site well comparatively higher than the average baseline value of the bone density at the extraction site in control site.

Conclusion

The study showed that autologous PRF is biocompatible and has significantly improved soft tissue healing. Bone regeneration and increase in bone density in extraction sockets. However, a more elaborate study with a large number of clinical cases is essential to be more conclusive regarding its efficacy.     

Autologous Platelet Rich Plasma After Third Molar Surgery: A Comparative Study

Purpose

This study is an attempt to evaluate the use of autologous platelet rich plasma (PRP) to promote wound healing and osseous regeneration in human third molar extraction sockets.

Materials and method

PRP was prepared after two centrifugation and the gelling agent used was freshly prepared 10% calcium chloride.PRP gel was placed in one of the extracted sockets of bilateral impacted mandibular third molars. IOPA Xrays were used to evaluate the wound dehiscence, probing depth, bone density & alveolar bone level after 1st, 2nd and 7th day and 3rd & 6th month respectively.

Results

On evaluation, it was found that PRP grafted sockets showed dehiscence in 8% cases. The decrease in alveolar bone level was highly significant in PRP grafted sockets in 3rd and 6th month post operatively. There was significant difference between pre-operative density of adjacent bone and bone formed in extraction sockets at 3rd and 6th month in PRP grafted sockets. There was significant reduction in probing depth from initial period to 3 and 6 months in both the groups, but PRP grafted sockets showed greater decrease in probing depth.

Conclusion

PRP is an inexpensive and widely available modality to minimize postoperative complication and enhance both hard and soft tissue healing potentials. This autologous product eliminates concern about immunogenic reaction and disease transmission. Its beneficial outcomes in dental clinic, including decrease in bleeding and rapid wound healing hold promise for further procedures.PRP is thus a new application in tissue engineering and developing area for clinician and researchers.     

Clinical Evaluation of Use of Platelet Rich Plasma in Bone Healing

Background

Tooth extraction is performed for a wide variety of reasons as we know. Several techniques aiming at enhancing the regeneration process in the extraction socket have been adopted such as filling the socket with autogenous bone grafts or bone substitutes. We know platelets play a central role in hemostasis and healing processes but relative contradictory effect of platelet in bone regenerating capacity have been published in different in vitro and in vivo studies.

Method

To explore this we used platelet-rich plasma (PRP) (autogenous) alone in empty extraction socket of bilateral impacted mandibular third molars. For that we selected five patients having bilateral impacted teeth. Out of two sockets one was used as intervention by filling with PRP and the other was allowed to heal without PRP. All patients were followed for clinical and radiological evaluation by using digital OPG view after 1 week, 1, 2 and 4 months period.

Result and conclusion

PRP enhanced the osteogenic response in initial bone healing at 1 month duration but there was no added benefit in late bone healing at 4 months period compared in both intervention and control groups. However PRP significantly improved the soft tissue healing in PRP treated sites compared to control group.     

Efficacy of Simvastatin in Bone Regeneration After Surgical Removal of Mandibular Third Molars: A Clinical Pilot Study

Introduction

Simvastatin, a common cholesterol-lowering drug that inhibits hepatic hydroxymethylglutaryl coenzyme A reductase, the rate-limiting enzyme in the mevalonate pathway, increases expression of the BMP-2 gene and thus promotes bone regeneration.

Materials and methods

A study was conducted in mandibular third molar sockets to study the efficacy of the drug by implanting it into sockets (experimental group) and observations were made over 3 months to compare the healing with the (control group).

Conclusion

The results showed faster regeneration of the bone in the simvastatin site using the gray level histogram values.     

Role of Platelet Rich Fibrin and Platelet Rich Plasma in Wound Healing of Extracted Third Molar Sockets: A Comparative Study

Aims and objectives

This prospective study was done to evaluate and compare the utility and effectiveness of platelet rich fibrin (PRF) with that of platelet rich plasma (PRP) on soft tissue healing and bone tissue healing of extracted third molar sockets.

Materials and methods

This study included split mouths of 20 patients who underwent bilateral extraction of impacted third molars. During the same appointment, following which PRF and PRP were prepared from patients’ autologous blood and placed in right and left extracted sockets, respectively. The data for soft tissue healing were recorded at end of 1 week, using healing index of Landry et al. and the data for bone tissue healing were recorded at the end of 4 months using digitalized orthopantomogram images on Adobe Photoshop CS; which was then compared between the two sites of the same patient.

Results

The mean values of soft tissue healing collected at 1 week post-operative, for PRF group were significantly higher as compared to PRP group. And the mean values of bone density collected at the end of fourth month post-operative, for PRF group were also significantly higher as compared to PRP group. Both tests showed p value of 0.00.

Conclusion

PRF is significantly better in promoting soft tissue healing and also faster regeneration of bone after third molar extraction, in comparison with PRP. This could be attributed to simpler preparation protocols of PRF over PRP and the ability of PRF to release growth factors in a controlled way.     

Efficacy of Platelet Rich Plasma and Hydroxyapatite Crystals in Bone Regeneration After Surgical Removal of Mandibular Third Molars

Purpose

This study evaluates the efficacy of platelet rich plasma (PRP) & porous hydroxyapatite crystals in bone regeneration after surgical removal of mandibular third molar with the help of radiographs and its comparison with control side.

Materials and Methods

A total of 40 patients; both male and female aged between 18 and 35 years, who had impacted mandibular third molars were randomly selected for this study. Twenty patients were taken for control group and 20 patients for study group. The extraction socket of the study group was packed with PRP and hydroxyapatite granules and that of control group was sutured without PRP and hydroxyapatite. The bone density of both extraction sockets were evaluated radiographically using gray level histogram and compared periodically on immediate postoperative day, 1st and 3rd month postoperatively and postoperative sequelae of both the control group and study group in terms of oedema & pain or any other adverse reactions were also assessed.

Results

Data suggested evidence of early bone formation and maturation radiographically in study group as compared to control group. The percentage of facial swelling was numerically greater on the control side as compared to the study side, Pain was also assessed with VAS and it was found that the severity of pain was equal in both study and control groups and the results were not significant.

Conclusion

This study clearly indicated a definitive improvement in the wound healing, increase in bone density, which signifies and highlights the use of PRP and hydroxyapatite granules, certainly as a valid method in inducing and accelerating bone regeneration.     

Differential expression of immunologic proteins in gingiva after socket preservation in mini pigs

During healing following tooth extraction, inflammation and the immune response within the extraction socket are related to bone resorption.

Objective

: We sought to identify how the alloplastic material used for socket preservation affects the immune responses and osteoclastic activity within extraction sockets.

Material and Methods

: Using a porcine model, we extracted teeth and grafted biphasic calcium phosphate into the extraction sockets. We then performed a peptide analysis with samples of gingival tissue from adjacent to the sockets and compared the extraction only (EO) and extraction with socket preservation (SP) groups. We also used real-time polymerase chain reaction (PCR) to evaluate the expression level of immunoglobulins, chemokines and other factors related to osteoclastogenesis. Differences between the groups were analyzed for statistical significance using paired t tests.

Results

: Levels of IgM, IgG and IGL expression were higher in the EO group than in the SP group 1 week post-extraction, as were the levels of CCL3, CCL5, CXCL2, IFN-γ and TNF-α expression (p<0.05). In addition, receptor activator of nuclear factor kappa-B ligand (RANKL) was also significantly upregulated in the EO group (p<0.05), as were IL-1β, IL-6 and IL-8 (p<0.05).

Conclusions

: These results suggest that the beneficial effect of socket preservation can be explained by suppression of immune responses and inflammation.     

Potential for osseous regeneration of platelet rich plasma: a comparitive study in mandibular third molar sockets

Purpose  

To evaluate the efficacy of autologous platelet-rich plasma in soft tissue healing & bone regeneration in mandibular third molar extraction socket.     

Eruption Status of Third Molar and Its Possible Influence on the Location of Mandibular Angle Fracture: A Retrospective Analysis

Introduction

This study was designed to evaluate the influence of eruption status of mandibular third molars on the location of mandibular angle fracture. We also aimed to evaluate the incidence of damage to mandibular third molar teeth (M3) and its roots.

Materials and Methods

Medical records and panoramic radiographs of 142 patient cohorts with mandibular angle fractures with third molars present were retrospectively reviewed.

Results

Revealed that incidence of angle fracture were high in patients with fully erupted M3 when compared to unerupted group. Out of 142 patients, 108 fractures were found involving the M3 socket and 14.1 % had damage to M3.

Conclusion

The presence of erupted mandibular third molar increases the chances of angle fracture when compared to impacted M3. Involvement of the M3 socket often resulted in increased operative time and complexity of the surgical procedure with possible removal of the damaged M3.     

Treatment with paracetamol, ketorolac or etoricoxib did not hinder alveolar bone healing: a histometric study in rats

Prostaglandins control osteoblastic and osteoclastic function under physiological or pathological conditions and are important modulators of the bone healing process. The non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase (COX) activity and consequently prostaglandins synthesis. Experimental and clinical evidence has indicated a risk for reparative bone formation related to the use of non-selective (COX-1 and COX-2) and COX-2 selective NSAIDs. Ketorolac is a non-selective NSAID which, at low doses, has a preferential COX-1 inhibitory effect and etoricoxib is a new selective COX-2 inhibitor. Although literature data have suggested that ketorolac can interfere negatively with long bone fracture healing, there seems to be no study associating etoricoxib with reparative bone formation. Paracetamol/acetaminophen, one of the first choices for pain control in clinical dentistry, has been considered a weak anti-inflammatory drug, although supposedly capable of inhibiting COX-2 activity in inflammatory sites.

Objective

The purpose of the present study was to investigate whether paracetamol, ketorolac and etoricoxib can hinder alveolar bone formation, taking the filling of rat extraction socket with newly formed bone as experimental model.

Material and methods

The degree of new bone formation inside the alveolar socket was estimated two weeks after tooth extraction by a differential point-counting method, using an optical microscopy with a digital camera for image capture and histometry software. Differences between groups were analyzed by ANOVA after confirming a normal distribution of sample data.

Results and conclusions

Histometric results confirmed that none of the tested drugs had a detrimental effect in the volume fraction of bone trabeculae formed inside the alveolar socket.     

Influence of two different surgical techniques on the difficulty of impacted lower third molar extraction and their post-operative complications

Background

Post-operative complications of various degrees of severity are commonly observed in third molar impaction surgery. For this reason, a surgical procedure that decreases the trauma of bone and soft tissues should be a priority for surgeons. In the present study, we compare the efficacy and the post-operative complications of patients to whom two different surgical techniques were applied for impacted lower third molar extraction.

Material and Methods

Patients of the first group underwent the classical bur technique, while patients of the second group underwent another technique, in which an elevator was placed on the buccal surface of the impacted molar in order to luxate the alveolar socket more easily.

Results

Comparing the two techniques, we observed a statistically significant decrease in the duration of the procedure and in the need for tooth sectioning when applying the second surgical technique, while the post-operative complications were similar in the two groups. We also found a statistically significant lower incidence of lingual nerve lesions and only a slightly higher frequency of sharp mandibular bone irregularities in the second group, which however was not statistically significant.

Conclusions

The results of our study indicate that the surgical technique using an elevator on the buccal surface of the tooth seems to be a reliable method to extract impacted third molars safely, easily, quickly and with the minimum trauma to the surrounding tissues. Key words:Mandibular third molar, impacted, surgical technique, extraction, elevator.     

Platelet-rich plasma plus bioactive glass in the treatment of intra-bony defects: a study in dogs

Objective

This study was designed to evaluate, histomorphometrically, the association of platelet-rich plasma (PRP) and bioactive glass (BG) in the treatment of periodontal intrabony defects.

Material and Methods

Nine mongrel dogs were included in the study. Three-wall intrabony defects were surgically created at the mesial and distal aspect of first mandibular molar and exposed to plaque accumulation for 1 month. The defects were randomly assigned to the groups: control, BG, PRP, PRP+BG. Dogs were sacrificed 90 days after the surgeries. The histometric parameters evaluated were: length of sulcular and junctional epithelium, connective tissue adaptation, new cementum, new bone, defect extension and area of new bone filling the defect.

Results

A superior area of new bone was observed in PRP+BG and BG (13.80±2.32 mm² and 15.63±2.64 mm², respectively) when compared to the other groups (8.19±1.46 mm² and 8.81±1.47 mm² for control and PRP, respectively). No statistically significant differences were observed in the remaining parameters.

Conclusion

Within the limits of this study, it may be concluded that PRP failed to provide statistically significant improvements in the histometric parameters.     

Platelet-rich plasma in the treatment of Class II furcation defects: a histometrical study in dogs

Objective

This study was designed to evaluate the potential adjunctive benefits of platelet-rich plasma (PRP) when used with guided-tissue regeneration (GTR) and bioactive glass (BG) in the treatment of Class II furcation lesions.

Material and Methods

Bilateral Class II furcation lesions were surgically created and allowed to become chronic in the mandibular third premolars of 9 dogs. The defects were randomly assigned to: A) GTR+BG and B) GTR+BG+PRP. Similar defects were created in the maxillary third premolars and received the same treatments after 45 days. Dogs were sacrificed 90 days after the first treatment. The histometric parameters evaluated were: connective tissue adaptation, new cementum, new bone, mineralized bone area, non-mineralized bone area, and residual BG particle area.

Results

Data analysis showed a superior length of new cementum and a greater mineralized bone area for group B in both periods (p<0.05). The non-mineralized bone area was greater in the control group (p<0.05) in both periods.

Conclusion

Within the limits of this study, it can be concluded that the use of PRP in the treatment of Class II furcation defects may enhance the amount of new cementum and provide a more mineralized bone in a shorter period of time.     

Effect of Diode Laser on Healing of Tooth Extraction Socket: An Experimental Study in Rabbits

Objectives

To evaluate the effect of low-level laser therapy on healing of extracted tooth socket of healthy rabbits.

Design

The sample of this study was 20 male rabbits of 2–2.5 kg weight with age range of 8–12 months. Right and left lower first premolar teeth were extracted. The extraction sockets of lower right first premolar were irradiated with 0.9 W gallium-aluminum-arsenide (GaAlAs) diode laser for 5 min, immediately after extraction and then every 72 h for the next 12 days. The extraction socket of left side were not exposed to laser and served as a control. The animals were sacrificed after 7, 14, 30 and 45 days and the experimental and control sockets were removed from the harvested mandibles and prepared for haematoxylin and eosin staining and Masson’s stain. The prepared slides were examined under light microscope for histological and histomorphometric examination.

Results

The histological examination showed that diode laser-treated sockets demonstrated early formed new bone with faster maturation of primary bone to secondary bone as compared to non-treated control sockets. Histomorphometric analysis revealed a statistically significant increase in the density and volume of trabecular bone in laser-treated sockets than control sockets.

Conclusion

Diode laser application to tooth extraction socket has a positive effect on bone formation.

     

A finite element study on stress distribution of two different attachment designs under implant supported overdenture

Objective

This study aimed to evaluate stress patterns generated within implant-supported mandibular overdentures retained by two different attachment types: ball and socket and locator attachments.

Materials and methods

Commercial CAD/CAM and finite element analysis software packages were utilized to construct two 3D finite element models for the two attachment types. Unilateral masticatory compressive loads of 50, 100, and 150 N were applied vertically to the overdentures, parallel to the longitudinal axes of the implants. Loads were directed toward the central fossa in the molar region of each overdenture, that linear static analysis was carried out to find the generated stresses and deformation on each part of the studied model.

Results

According to FEA results the ball attachment neck is highly stressed in comparison to the locator one. On the other hand mucosa and cortical bone received less stresses under ball and socket attachment.

Conclusions

Locator and ball and socket attachments induce equivalent stresses on bone surrounding implants. Locator attachment performance was superior to that of the ball and socket attachment in the implants, nylon caps, and overdenture. Locator attachments are highly recommended and can increase the interval between successive maintenance sessions.     

The Local Effect of Alendronate with Intra-alveolar Collagen Sponges on Post Extraction Alveolar ridge Resorption: A Clinical Trial

Introduction

Extraction of teeth is followed by resorption of the residual alveolar ridge that continues throughout life resulting in loss of alveolar height and width. Of the numerous techniques that have been used to arrest post extraction alveoloar ridge resorption, the placement of a graft material inside the socket immediately after extraction has been mostly followed. Type 1 collagen is one of the commonly used graft material that prevent resorption by providing dimensional stability to the socket. Bisphosphonates are an anti-osteoclastic drug that prevent resorption by disrupting the membrane ruffling of the osteoclasts. Alendronate a bisphosphonate, is primarily used in diseases with bone loss. It has been used to reduce active bone resorption significantly without interfering with bone mineralization and quality. The need for the study is to examine the inhibitory effect of alendronate on residual ridge resorption when applied locally in combination with type I collagen on alveolar bone immediately following tooth extraction.

Materials and Methods

Twenty patients with age between 30 and 65 years were selected from the out patient department of The Oxford Dental College and Hospital. The patients were divided into two groups. In the first group after extraction of teeth from premolar to midline the sockets were irrigated with saline and sutured. On the left side type I collagen sponge was placed and sutured. In the other group the right side was treated the same way after extraction as in first group where as in the left side sockets type I collagen soaked in 20 mg/ml of alendronate was placed and sutured. Patients were evaluated clinically for any local irritation as well as radiologically with orthopantomograph X-rays were taken immediately after the extraction, 1 month after extraction and 4 months after extraction to determine the amount of bone loss prevented.

Results

The statistically significant bone loss prevented by the collagen alone was 22.8 % and in collagen with alendronate group was 44.38 % at the end of 4 months.

Conclusion

Type I collagen soaked with alendronate when placed in the socket immediately after extraction of teeth prevents post-extraction alveolar ridge resorption.     

The Effect of Alloplastic Bone Graft and Absorbable Gelatin Sponge in Prevention of Periodontal Defects on the Distal Aspect of Mandibular Second Molars,After Surgical Removal of Impacted Mandibular Third Molar: A Comparative Prospective Study

Aim

Recent studies claim that haemostatic agents can be used as bone graft substitutes. The aim of this study was to compare the efficacy of alloplastic bone graft with absorbable gelatin sponge in prevention of periodontal defects distal to mandibular second molar after the surgical removal of impacted mandibular third molars.

Materials and methods

A prospective, randomized, single-blind split-mouth study was designed. The study consisted of 25 patients requiring surgical removal of bilateral impacted mandibular 3rd molars. The surgical sites were randomly divided into 2 groups: group I: G-graft (hydroxyapatite + collagen, study group) and group II: Abgel (absorbable gelatin sponge, control group). Patients were recalled on lst and 7th postoperative days and 3rd and 6th postoperative months. Probing depth, alveolar bone levels and soft tissue wound healing were evaluated. Paired t test was used to compare pre and post-operative alveolar bone levels and probing depth (PD). Wilcoxon signed ranks test was used to compare the wound healing.

Results

The soft tissue wound healing, PD and the distance between the cemento–enamel junction on the distal aspect of mandibular second molar (point A) and the alveolar crest on the distal aspect of the same tooth (point B) were significantly higher in group I as compared to group II.

Conclusion

This study reveals an increase in the alveolar bone level, improvement of PD and better wound healing in group I. Group II subjects required longer healing time than the normal. The authors disagree the claim that the haemostatic agents can be used as bone graft substitutes. However, long-term, multicenter, randomized controlled clinical trials are required.     

Bone remodeling at microscrew interface near extraction site in the beagle dog mandible-histologic and immunohistochemical analyses

Extraction is often used as part of orthodontic therapy, and good control of anchorage is a key step after extraction. Although microscrews can be implanted close to the extraction site in order to achieve orthodontic support, the efficiency of bone remodeling at the implant-bone interface near the extraction region is dubious.

Objective

The purpose of this study was to investigate bone remodeling of the bone-microscrew interface near the tooth extraction site, in the absence of loading.

Material and Methods

Third and fourth premolars were extracted from the mandibles of beagle dogs, followed by placement of test microscrews near the extraction sites. Control microscrews were placed further away from the extraction site. All samples were collected after 1, 3, 8, or 12 weeks of healing following extraction. The bone remodeling process at the interface was evaluated using histologic and immunohistochemical analyses.

Results

Initially, a large number of inflammatory cells were aggregated at the interface. The expression levels of core binding factor (Cbfa1), osteocalcin (OC) and transforming growth factor beta (TGF-β) were inconspicuous in both groups, whereas tumor necrosis factor alpha (TNF-α) was strongly expressed, especially in the test groups (P<0.05). Subsequently, the expression levels of Cbfa1, OC and TGF-β were found to increase significantly, and active osteogenesis was observed.

Conclusions

During week 1, inflammatory reaction is a major concern at the bone-microscrew interface near the extraction site. However, with healing, the influence of extraction on the remodeling of bone surrounding the microscrews decreases, thus facilitating successful treatment.     

A histological and micro-CT investigation in to the effect of NGF and EGF on the periodontal,alveolar bone,root and pulpal healing of replanted molars in a rat model - a pilot study

Background

This study aims to investigate, utilising micro-computed tomography (micro-CT) and histology, whether the topical application of nerve growth factor (NGF) and/or epidermal growth factor (EGF) can enhance periodontal, alveolar bone, root and pulpal tissue regeneration while minimising the risk of pulpal necrosis, root resorption and ankylosis of replanted molars in a rat model.

Methods

Twelve four-week-old male Sprague-Dawley rats were divided into four groups: sham, collagen, EGF and NGF. The maxillary right first molar was elevated and replanted with or without a collagen membrane impregnated with either the growth factors EGF or NGF, or a saline solution. Four weeks after replantation, the animals were sacrificed and the posterior maxilla was assessed using histological and micro-CT analysis. The maxillary left first molar served as the control for the corresponding right first molar.

Results

Micro-CT analysis revealed a tendency for all replanted molars to have reduced root length, root volume, alveolar bone height and inter-radicular alveolar bone volume. It appears that the use of the collagen membrane had a negative effect while no positive effect was noted with the incorporation of EGF or NGF. Histologically, the incorporation of the collagen membrane was found to negatively affect pulpal, root, periodontal and alveolar bone healing with pulpal inflammation and hard tissue formation, extensive root resorption and alveolar bone fragmentation. The incorporation of EGF and NGF did not improve root, periodontal or alveolar bone healing. However, EGF was found to improve pulp vascularisation while NGF-improved pulpal architecture and cell organisation, although not to the level of the control group.

Conclusions

Results indicate a possible benefit on pulpal vascularisation and pulpal cell organisation following the incorporation of EGF and NGF, respectively, into the alveolar socket of replanted molars in the rat model. No potential benefit of EGF and NGF was detected in periodontal or root healing, while the use of a collagen membrane carrier was found to have a negative effect on the healing response.     

Evaluation of subcutaneous and alveolar implantation surgical sites in the study of the biological properties of root-end filling endodontic materials

Objective

The aim of this study was to compare two methodologies used in the evaluation of tissue response to root-end filling materials in rats.

Material and Methods

Forty rats were divided into 4 groups: in Groups I and II (control groups), empty polyethylene tubes were implanted in the extraction site and in the subcutaneous tissue, respectively; in Groups III and IV, polyethylene tubes filled with ProRoot MTA were implanted in the extraction site and in the subcutaneous tissue, respectively. The animals were killed 7 and 30 days after tube implantation, and the hemi-maxillas and the capsular subcutaneous tissue, both with the tubes, were removed. Specimens were processed and evaluated histomorphologicaly under light microscopy. The scores obtained were analyzed statistically by the Kruskal-Wallis test (p<0.05).

Results

There were no statistically significant differences between the implantation methods (p=0.78033, p=0.72039). It was observed that the 30-day groups presented a more mature healing process due to smaller number of inflammatory cells.

Conclusion

The present study showed no differences in tissue responses as far as the implantation site and the studied period were concerned. Alveolar socket implantation methodology represents an interesting method in the study of the biological properties of root-end filling endodontic materials due to the opportunity to evaluate bone tissue response.