**4. Conclusions and closing remarks**

comparing with SCTG (the current "*gold standard*" technique for treating Miller Class I and II gingival recessions); indicating that L-PRF/CAF could be a safer and less invasive alternative to current grafting techniques, and a more cost-effective strategy or approach than EMD is in

Resorption of the upper jaw bone after tooth loss is a frequent problem faced in posterior maxillary implant placement due to lack of sufficient bone mass for anchorage. Common maxillary sinus augmentation techniques provide a solution via increasing the available bone height at the expense of sacrificing volume of the maxillary sinus [23]. Traditionally, autologous bone grafts and resorbable membranes are used to promote osteogenesis and avoid soft tissue in-growth into the surgical site. However, donor site morbidity and size restrictions, latter resorption of the graft and high-cost of membranes, are main disadvantages [24, 25]. In this context, L-PRF appears to provide a promising alternative overcoming such limitations. In this review, two RCTs evaluating the use of L-PRF in lateral window sinus augmentation were found. Applications were performed either as: (a) grafting material (L-PRF/Bio-Oss® constructs vs. Bio-Oss®) [26] or (b) absorbable covering membrane for the lateral osteotomy window (L-PRF vs. Geistlich Bio-Gide®) [27]. In both studies, included subjects were systemically healthy adults with maxillary atrophy (defined as <5 mm residual bone crest height measured in OPG/orthopantomogram). Smoking status was not assessed. The addition of L-PRF to Bio-Oss® bone-substitute revealed neither advantages nor disadvantages over Bio-Oss® alone controls [26]. After 6 months, clinical and radiographic examinations revealed both groups exhibiting similar amounts and density of mineralized tissues, with no signs of material resorption. Histological evaluations also showed non-significant differences regarding: (a) percentage of newly formed bone, (b) percentage of residual Bio-Oss®, (c) bone-to-bonesubstitute contact, and (d) post-treatment inflammatory reactions [26]. Regarding coverage of lateral osteotomy sinus window, L-PRF use resulted in a similar amount of vital bone formation (%) and residual bone-substitute when compared to Bio-Gide® controls (L-PRF: 17.0 and 15.9%, Bio-Gide®: 17.2 and 17.3%, differences are not statistically-significant). Overall, despite a slightly superior to no coverage at all (12.1%), it can be stated that results were similar to those reported using other conventional membranes (collagen: 17.6%; e-PTFE: 16.9%) [27]. Within the presented limitations in both RCTs, evidence suggests that L-PRF is a safe, simple to use and handle, and cost-effective alternative to traditional bone grafts and absorbable membranes; in low-income patients, pursuing maxillary sinus augmentation procedures.

Post-extraction changes in alveolar bone compromise prosthodontic rehabilitation with fixed, removable and/or implant-supported prosthesis. Alveolar Ridge Preservation (ARP) is a technique which involves the use of grafting and barrier materials in order to significantly reduce post-extraction bone loss [28]. L-PRF has been demonstrated to accelerate/enhance bone repair [29, 30], promote fibroblast proliferation [3, 30] and increase vascularity [31]; thereby potentially favoring the post-extraction healing process and the ARP approach. Yet, a single

treating Miller Class I and II gingival recessions (**Figure 3C**).

114 Bone Grafting - Recent Advances with Special References to Cranio-Maxillofacial Surgery

**3.4. L-PRF in sinus floor augmentation**

**3.5. L-PRF in alveolar ridge preservation**

Tissue regeneration and anatomical reconstruction in defects of the oro-maxillo-facial complex have been always a critical and controversial issue. Both, quality and quantity of the regenerated tissues are important to consider, esthetically and functionally. Practically, the surgeon is faced with an ample collection of regenerative techniques and materials to choose from. *How can one select the "ideal" or "best-fit" strategy and procedure for an optimal clinical outcome? Evidence-based studies? Level of evidence?* To the best of our knowledge, this is the first review of Randomized Controlled Clinical Trials on L-PRF use and application in Oral Surgery. While the available literature is found to be highly-limited, L-PRF *can be* indicated as an innovative *tool* for contemporary oro-maxillo-facial tissue regeneration and bioengineering. Indeed, existing evidence suggests that L-PRF improves early wound healing and promotes post-surgical bone formation/maturation. However, it is noteworthy that a clearer consensus seems to be present regarding its significant beneficial impact on post-surgical pain and discomfort control, regardless the type of procedure. Unlike its predecessors, new L-PRF preparations tend to function more as biologically-active biomaterials and scaffolds for the delivery of autologous cells, cytokines and growth factors.

the Faculty of Dentistry and PMI (Plan de Mejoramiento Institucional en Innovación I+D+i), Department for Research, Development and Innovation, Universidad de los Andes, Santiago de Chile. The author acknowledges supplementary operating funding provided from CONICYT-FONDEF Chile under awarded project/grant (national) **# ID16I10366** (2016–2019) and Fondo de Ayuda a la Investigacion FAI - Universidad de los Andes No. **INV-IN-2015-101** (2015–2019).

L-PRF: A "Super" Biomaterial for Naturally Guided Hard/Soft Tissue Bioengineering and Regeneration...

http://dx.doi.org/10.5772/intechopen.78672

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1 BioMAT'X, Facultad de Odontología, Universidad de los Andes, Santiago, Chile

2 Plan de Mejoramiento Institucional (PMI) en Innovación I+D+i, Universidad de los Andes,

3 Programa de Doctorado en BioMedicina, Facultad de Medicina, Universidad de los Andes,

4 Centro de Investigación e Innovación Biomédica, Facultad de Medicina, Universidad de

[1] Habibovic P, de Groot K. Osteoinductive biomaterials—Properties and relevance in bone repair. Journal of Tissue Engineering and Regenerative Medicine. 2007;**1**:25-32.

[2] Haidar ZS. NanoDentistry: Perspectives on the role of NanoBiotechnology in biomaterials, pharmaceutics and BioDental tissue engineering. EC Dental Science. 2015;**3**:506-507 [3] Dohan DM, Choukroun J, Diss A, Dohan SL, Dohan AJJ, Mouhyi J, Gogly B. Platelet-rich fibrin (PRF): A second-generation platelet concentrate. Part II: Platelet-related biologic features. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontics.

[4] Del Corso M, Vervelle A, Simonpieri A, Jimbo R, Inchingolo F, Sammartino G, Dohan Ehrenfest DM. Current knowledge and perspectives for the use of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) in oral and maxillofacial surgery. Part 1: Periodontal and dentoalveolar surgery. Current Pharmaceutical Biotechnology. 2012;**13**:1207-1230 [5] Dohan Ehrenfest DM, Rasmusson L, Albrektsson T. Classification of platelet concentrates: From pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF). Trends in Biotechnology. 2009;**27**:158-167. DOI: 10.1016/j.tibtech.2008.11.009 [6] Simonpieri A, Del Corso M, Vervelle A, Jimbo R, Inchingolo F, Sammartino G, Dohan Ehrenfest DM. Current knowledge and perspectives for the use of platelet-rich plasma

**Author details**

Ziyad S. Haidar1,2,3,4\*

Santiago, Chile

Santiago, Chile

**References**

los Andes, Santiago, Chile

DOI: 10.1002/term.5

\*Address all correspondence to: zhaidar@uandes.cl

2006;**101**:e45-e50. DOI: 10.1016/j.tripleo.2005.07.009

Thus, L-PRF should be considered a "living tissue" preparation for natural guided tissue regeneration and not simply a "growth factor-rich" surgical adjuvant. Yet, it is safe to say that this remains an un-explored territory in Dental Biomaterial (Dental Bioengineering) Research, in general.

Our group is currently investigating the potential of incorporating oral-derived mesenchymal stem cells or growth-factor embedded nanoparticles within the L-PRF, as "*super*" or "*smart*" bio-scaffolds, to further boost, with predictability, bone formation, soft tissue healing, treatment time and post-surgical stability, in advanced oro-maxillo-facial surgical procedures such as Periodontally-Accelerated Osteogenic Orthodontics.

Our research extends to investigate the potential of L-PRF in reducing the need for prescription drugs following invasive surgical procedures such as third molar extraction and cysts resections.

Finally, we are vigorously working on characterizing the rheological and biological variations of L-PRF, alongside partnering up with nurses, physicians and dentists to standardize the preparation protocol, for use in other therapeutic indications.
