Effectiveness of Plasma-Rich Fibrin and De-Epithelialized Free Gingival Graft in the Treatment of Gingival Recessions.

Introduction/Aim: Soft tissue dehiscences such as gingival recessions are a very common problem that we face in modern periodontics. This clinical study aimed to analyze the effectiveness of surgical procedures using a de-epithelialized gingival graft (DGG) combined with a coronally advanced flap and to evaluate the application of plasma-rich fibrin (PRF). Methods: The study included 40 teeth (20 patients) with Miller class I and II gingival recessions. Twenty recessions (20 patients) were treated utilizing the de-epithelialized gingival graft in combination with the coronally advanced flap, and on the opposite side of the jaw, the same number of recessions were treated utilizing plasma-rich fibrin combined with the coronally advanced flap. To evaluate tissue condition and the clinical parameters before and after the surgical procedure, the following parameters were used: the degree of epithelial attachment (DEA), the width of keratinized gingiva (WKG), and the vertical depth of recession (VDR). Results: based on the achieved results and the analysis of clinical parameters, a statistically significant reduction in the vertical depth of recession was proven in both groups, with very similar mean percentages of root coverage, with the difference being that the stability of the soft tissues of the treated region was more visible in the DGG. Conclusion: using modern surgical procedures allows the regeneration of not only the soft tissues but also deeper periodontal tissues.

Treatment of Early Developed Peri-Implantitis in Fibula Graft Site.

The fibula microvascular free flap technique and placement of dental endosseous implants seem to be viable options for reconstructing the mandible, following a resective jaw surgery. The causes of early failures of implants include bone overheating, latent infection by surgical trauma, the factors related with the implant, and overcompression. This case report reviews the mechanisms of early post-implantation bone loss, and suggests the course of treatment for early peri-implantitis for implants that show no mobility. Radiographs and clinical data presented have shown that the surgical treatment of early developed peri-implantitis using GBR methods in free fibula graft sites offers promising and stabile results.

Treatment of a large radicular cyst-enucleation or decompression?

INTRODUCTION: Radicular cysts treatment involves surgical approach, more or less aggressive. However, treatment of large cystic lesions, including radicular cysts, causes some of dilemmas concerning the choice of the surgical method, especially the degree of radicalism. CASE REPORT: We presented a 65-year-old male patient with large radicular cyst in the mandible. A large elliptical multilocular radiolucency, located in the left side of the mandible, being in close vicinity to the mandibular canal, was registered at the orthopantomographic radiography. There was a risk of pathological fracture of the mandible. However, the cyst was completely removed by enucleation without intraoperative and postoperative complications. CONCLUSION: The presented case support the opinion that careful enucleation of large mandibular cysts may be done without complications, such as damages of surrounding anatomical structures or mandibular fracture. The authors indicate reasons for strong support of the undertaken surgical approach of treating large radicular cysts in the mandible.

The impact of thickness of resorbable membrane of human origin on the ossification of bone defects: a pathohistologic study.

BACKGROUND/AIM: A wide range of resorbable and non-resorbable membranes have been investigated over the last two decades. The barrier membrane protects the defect from ingrowth of soft tissue cells and allows bone progenitor cells to develop bone within a blood clot that is formed beneath the barrier membrane. The membranes are applied to reconstruct small bony defect prior to implantation, to cover dehiscences and fenestrations around dental implants. The aim of this study was to evaluate the influence of human resorbable demineralized membrane (RHDM) thickness on bone regeneration. METHODS: The experiment, approved by Ethical Committee, was performed on 6 dogs and conducted into three phases. Bone defects were created in all the 6 dogs on the left side of the mandible, 8 weeks after extraction of second, third and fourth premolars. One defect was covered with RHDM 100 micro thick, one with RHDM 200 micro thick, and the third defect left empty (control defect). The histopathological analysis was done 2, 4 and 6 months after the surgery. In the third phase samples of bone tissue were taken and subjected to histopathological analysis. RESULTS: In all the 6 dogs the defects treated with RHDM 200 micro thick showed higher level of bone regeneration in comparison with the defect treated with RHDM 100 micro thick and especially with empty defect. CONCLUSION: Our results demonstrated that the thicker membrane showed the least soft tissue ingrowths and promoted better bone formation at 6 months compared with a thinner one.

[Histopathological evaluation of bone regeneration using human resorbable demineralized membrane].

BACKGROUND/AIM: Filling a bone defect with bone substitution materials is a therapy of choice, but the infiltration of connective tissue from the mucoperiostal flap may compromise a healing of bone substitutions with bony wall defects. Application of membrane as a barrier is indicated as a solution to this problem. The aim of this study was to show a pathohistological view of bone regeneration and the significance of human resorbable demineralized membrane (HRDM), 200 microns thick in bone regeneration regarding mandibular defects in an experiment on dogs. METHODS: The experiment was performed on six dogs. Bone defects were created in all six dogs on the right side of the mandible after the elevation of the mucoperiostal flap. One defect was filled with human deproteinised bone (HDB), and in between HDB and soft tissue RHDM of 200 microns thick was placed. In the second defect, used as a control one, only HDB without RHDM was placed. Two dogs were sacrificed two months after the surgery, another two dogs four months after the surgery and the last two dogs six months after the surgery. After that, samples of bone tissue were taken for histopathological analysis. RESULTS: In all the six dogs with defects treated with HDB and RHDM the level of bone regeneration was much higher in comparison with the control defects without RHDM. CONCLUSION: Membrane, as a cover of bony defect, is useful and benefits bone regeneration. Bony de fects covered with RHDM show better bony healing despite the fact that bone regeneration was not fully complete for as long as six months after the RHDM implantation.

[Impact of dental implant insertion method on the periimplant epithelial seal--experimental study on dogs].

BACKGROUND/AIM: There is a controversial opinion among implantologists on the method of dental implantation that provides more favourable response of soft and bone tissues. The aim of this study was to pathohistologicaly compare the influences of one- and two-phase implant surgical methods on the periimplant epithelial tissues. METHODS: The experiment was performed on 10 dogs. Eight weeks following tooth extractions implants were inserted using one phase method on the right side of the mandible, and two-phase method on the left one. Three months after implantation the animals were sacrificed. Contact regions of epithelial and subepithelial tissues and implants were pathohistologicaly examined, the elements of analysis were scored and compared. RESULTS: Epithelial tissue was not found in the two samples of one-phase implants, while in the remainder of samples the structure of basal membrane was preserved, massive inflammatory infiltrate was found in one, and partial necrosis was found in three samples. Epithelial tissue was not found in the three samples of two-phase implants, in three samples the structure of basal membrane was intact, while in three remained samples the membrane could not be detected; moderate inflammatory infiltrate was found in four samples and massive inflammatory infiltrate in both two remained samples; tissue necrosis, which was observed in the half of the samples, was complete. In subepithelial gingival tissues around one-phase implants the number of blood vessels was increased in three samples, accompanied by the thickening and dilatation of vascular walls, proliferation of blood elements, altered vascular walls and inflammatory cell infiltrate was found in four samples. CONCLUSION: On the base of the analized characteristics of epithelial and subepithelial tissues in contact with dental implants, one-phase method of implantation showed a more favorable tissue response.

[Effect of local administration of platelet-rich plasma and guided tissue regeneration on the level of bone resorption in early dental implant insertion].

BACKGROUND/AIM: Osseointegration is a result of cellular migration, differentiation, bone formation, and bone remodeling on the surface of an implant. Each of these processes depends on platelets and blood coagulum. Platelet-rich plasma (PRP) is used to improve osseointegration and stability of implants. The aim of the research was to test the influence that PRP and guided tissue regeneration in bone defects have on bone defect filling and the level of bone resorption in early implant insertion. METHODS: This experimental study included 10 dogs. A total of 40 BCT implants were inserted, 4 in each dog (two on the left side and two on the right side), with guided tissue regeneration. Radiologic analyses were done immediately after the insertion and 10 weeks after the insertion. Bone defect filling was measured by a graduated probe 10 weeks after the implant insertion. The following protocols were tested: I - PRP in combination with bovine deproteinized bone (BDB) and resorptive membrane of bovine origin (RBDM), II - BDB + RBDM, III - PRP + RBDM and IV - RBDM. RESULTS: The applied protocols affected differently the bone defect filling and the level of bone resorption. Significantly better results (the lowest bone resorption) were achieved with protocol I (PRP + BDB + RBDM) in comparison with protocols III (PRP + RBDM) and IV (RBDM), but not with protocol II (BDB + RBDM). On the other hand, no significant difference was found among protocols II (BDB + RBDM), III (PRP + RBDM) and IV (RBDM) in the level of bone tissue resorption. CONCLUSION: The bone defect filling was largest and the level of bone resorption was lowest in the protocol with PRP applied in combination with BDB and RBDM.

Clinical parameters of the local anesthetic effects of bupivacaine applied with and without a vasoconstrictor in oral implantology.

BACKGROUND/AIM: Bupivacaine (Marcaine), homologue of mepivacaine, chemically related to lidocaine, is used as a local anesthetic for local infiltration, peripheral nerve block, retrobulbar block, symphathetic block, and caudal and epidural anesthesia. The aim of this investigation was to determine and to compare clinical parameters of the local anesthetic effects of bupivacaine applied with and without a vasoconstrictor. METHODS: This investigation included a total of 30 randomly selected patients, who ranged in age from 30-60 years, with partial or total anodontia in the molar region of the mandible. These patients with total or partial edentulous molar part of the mandible, scheduled for dental implantation placement, were asked to participate in the study. In the first phase of the investigation, the patients were subjected to local anesthesia with 3.5 cm3 of 0.5% bupivacaine with a vasoconstrictor (adrenalin, 1: 200,000) in the right side of the mandible. After administering local anesthesia, the placement of blade, cylindrical, transdental (B.C.T.) implants was performed. In the second stage of the investigation, in 7-10 days period after the first oral surgery, the patients were subjected to local anesthesia with 3.5 cm3 of 0.5% bupivacaine, but without a vasoconstrictor, in the left side of the mandible. After administering local anesthesia, the placement of B.C.T. implants was performed. During the performance of both oral surgery procedures, the following clinical parameters of the local anesthetic effects were monitored: latent period, duration and the potency of anesthesia, and the evaluation of the postoperative pain level. RESULTS: The latent period under local anesthesia with 3.5 cm3 of 0.5% bupivacaine and vasoconstrictor was statistically significantly shorter than without vasoconstrictor. The duration of local anesthesia was longer without vasoconstrictor. There was no difference in the potency of anesthesia with or without a vasoconstrictor, while the lowest level of postoperative pain was found after administering bupivacaine without a vasoconstrictor use. CONCLUSION: The results of this investigation show that bupivacaine without a vasoconstrictor is efficient when used for local anesthesia in placing dental implants since it provides better blood circulation required for good dental implant osseointegration.

[Local application of concentrated trombocytes and the level of osseointegration of dental titanium implants: a histomorphometrical analysis].

BACKGROUND/AIM: In order to achieve better, and, thus an increased bone-implant interface, growth factors have been used over the past few years. All growth factors considered have fundamental role in the growth and development of cells and tissues. Concentrated trombocytes from platelet-rich plasma (CT-PRP) are fraction of the blood. Thrombocytes contain a number of growth factors namely PDGF, TGF-beta, IGF, VEGF and many others, which contribute to the achievement of the increased bone-implant interface, the increased stability of implants and the faster functional loading of implants. The aim of this study was to establish the effect of CT-PRP on bone-implant interface. METHODS: This experimental study included six dogs in which 24 BCT implants were inserted (4 implants per dog). On the left side of the lower jaw 2 implants were placed with CT-PRP, while on the right side the implants were placed without CT-PRP. The animals were sacrificed after 42, 70, and 98 days. The specimens were examined histomorphometrically, and analyzed 42, 70 and 98 days after the implant insertion. The contacts bone to implant in 16 zones for each analyzed implant were measured according to the established protocol. RESULTS: Results obtained with histomorphometrical analysis imply the increased bone-to-implant contact by use CT-PRP. The difference of the bone-to-implant contacts between these two groups of inserted implants has been particularly pronounced at six weeks after the implant insertion. CONCLUSION: According to the obtained results in the measurement of the level of osseointegration of the inserted implants, it should be advisable to use the CT-PRP method because it provides the higher level of osseointegration.