EVALUATION OF MINERALIZED PLASMATIC MATRIX DURING SINUS LIFT WITH THE SIMULTANEOUS PLACEMENT OF DENTAL IMPLANTS

Objectives: Mineralized plasmatic matrix is reported to improve the quality of the bone/fibrin mixture, creating a stable and easy to handle homogeneous material. However, few studies evaluate the use of the mineralized plasmatic matrix during sinus lift with the simultaneous placement of dental implants. Purpose: This study evaluated the efficiency or not of MPM compared to the xenograft bone grafting in the maxillary sinus lift. Patients and methods: This study was conducted randomly on patients selected for treatment with a total of augmentation xenograft in relations of changes in volume atdifferents time-points augmentation of sinus by CBCTscan. study null hypothesis that attendance be in the formation of new among two


Patient grouping:
Participating patients were divided into two equal and random groups; control group and study group.

The control group:
Sinus floor elevation with simultaneous implant placement was achieved. As a grafting material, Xenograft was used.

The study group:
Sinus floor elevation with simultaneous implant placement was achieved. Xenograft was used as a grafting material in the form of MPM.
Methods:-Surgical procedure: Surgery was performed under local anesthesia (lidocaine 1:80,000 epinephrine). The modified approach of Caldwell-Luc was used to achieve admission to the cavity of sinus. The lateral wall of the maxilla was exposed with a fullthickness mucoperiosteal flap made with crestal incision was made using a no. 15 blade and two vertical incisions on the buccal side of the residual alveolar ridge mesially and distally. The lateral window size was determined by how many implant to be inserted with attention to diminish the size of the lateral window as possible. A bony window was then traced using a Piezo-surgical unit.

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Firstly, bone was marked using tip end B S 5. This was followed by deepening of mark using SL1 tip. Cutting of bone was madeuntil a very thin plate of buccal bone remained above the lining of the sinus. A dental handle mirror was then used to break the buccal plate remaining. The section fractured of bone was detached from the antral lining and effort ended to detach it from the lining of sinus membrane.The tip of SL2 was used to improve the bony window, This was followed by the SL3 tip to raise the lining in the vicinity of the bony window. The partially raised lining was then lifted to a greater extent using the BS4 and BS5 tips. (9) MPM Preparation: A total number of 10 ml of venous blood was drawn into two 9 ml vacutest tubes and immediately centrifuged at 2500 rpm for 12 min. )10( Upon completion, a liquid yellow plasma on the top of the tube was seen separated from the erythrocyte at the bottom of the tube. The yellow part was then collected using a syringe, and added to acup that contains the bone graft material. The whole materialwas then mixed for a few seconds to obtain the MPM. The obtained biphasic matrix was then cut into pieces, and introducedinto sub-antral space as in the control group.

Suturing:
Non-resorbable suture material was used to accomplish a water tight, primary closure of the flap by using of mattress horizontal sutures occupied 5 mm far from the line of incision. In addition, another row of interrupted sutures was done 3 mm from the incision line to ensure hermetic seal.

Implant Stability:
Implant stability quotient (ISQ): numerical value (0-100) recorded immediately after implant insertion and expressing resonance frequency analysis (RFA). The Osstell® (PT) was used to evaluate the implant stability at the insertion of implant (PT0) as well as loading visit (PT1).

Radiographic Assessment :
Cone Beam Computed Tomography scans of were conducted at the preoperative visit (T X), 1 week subsequent to sinus lift surgery (first line, T0), at six months after loading (T1), and sixmonths after implant loading (T2). Scans for all patients were reserved by a PlanmecaProMax® three D unit ⃰ used imaging fixed parameter at each scanning. Altogether data of DICOM were formerly investigated used PlanmecaRomexis® softtware ® .

Results:-
This study was conducted on sixteen patients; fourteen females and two males, who met the inclusion criteria. Patients' age ranged from 20 to 60 years with a mean age of 44.63±8.55 years of control group and 42.50±11.35 in the study group. A total number of 16 sinus floor elevations were performed. Twenty-six dental implants were inserted simultaneously to replace sixteen missing first molars and eight missing second molars and two premolars. The control group included five sinus lift procedures made in four patients, with a mean age of 46.6±10.8 years. In the study group, also five sinus lift procedures were performedfor four patients with a mean age of 35.8±9 years.
The control group included eight sinus lift procedures made in eight patients. In the study group, also sinus lift procedures were made in eight patients. The implant lengths used in all cases were 10, 11.5, and 13. The implant diameters were 3.5 mm (50%, five implants), 4 mm (40%, four implants), and 4.5 mm (10%, one implant).

Clinical Evaluation:
All implants were successfully Osseo-integrated indicating an overall survival rate of 100% throughout the entire follow-up period.

Implant Stability at T0:
For the control group, the ISQ values at T 0 ranged from 40 to 65 N/cm, with a mean value of 53.88±7.55. For the study group, the ISQ values at T 0 ranged from 51 to 68 N/cmwith a mean value of 61.63±7.37N/cm. There was no statistically significant difference between the two groups.

Implant Stability at T1:
Implant stability was assessed after 6 months of implant insertion (T 6 ). For the control group: the ISQ values at T 6 ranged from 82 to 95, with a mean of 89.25±4.65. For the study group; the ISQ values at T 6 ranged from 82 to 95, with a mean of 87.75±5.70.There was no statistically significant difference between the two groups at T 6 .

Discussion:-
This study hypothesized that the use of growth concentrated factors collective with a graft material of bone produce improved outcomes in terms of implant stability and the stability of graft volume when associated to the usage graft bone alone.
This study assessed the MPM efficacy used in augmentation of maxillary sinus for encouraging the formation of new bone. We similarly related MPM and xenograft bone in relations of changes in volume atdifferents time-points ,subsequently augmentation of sinus by CBCTscan. The study null hypothesis was that attendance would be an alteration in the formation of new bone among two groups.
Thestability of implant maintaining and achieving are requisites for successful of a dental implants. The stability of implant can be defined as absence ofthe clinical mobility, which is also the definition suggests of osseointegration. Implant primary stability at assignment is a mechanical phenomenon that is associated with the quantity and quality of local bone, the type of implant placement and used technique. Implant secondary stability is the instability increase quality able toform bone and remodeling at the tissue interface/implant and the bone in the surrounding tissue. (11,12) Many studies have recognizedthat the ridge width and residual bone height appear to be the factor that mostlyinfluence the survival rate of implant with sinus floor elevation by lateral techniques. In our study, all implants successfully displayedOsseo integrated; they were introduced into the maxilla in the posterior area with bone height ranging from 3-7 mm in the sub antral residual ridge. (13) In this study stabilization of implant was achieved with the micro-threads of the implant neck and tapered profile. The design of implant appeared a relevant parameter as the implant stability is a parameter key for bone regeneration and osseointegration. Thus, the use of micro-threaded and tapered implant's is a simple choice and more secure than the use of implant that cylinder-type. In agreement with other research conducted by Pommer et al. 14 and Degidi et al. 15 Though, different profiles lead to the same outcomes, if used surgical procedure with the adequate careful. (16,17) All implants in both groups, in our study had ISQ ranging values ranging from 40 to65 for the control group. In the study group, values ranged from 51to 68 representing stability primary, which is essential for dental implant success.
Regarding the implant stability observedthere was no statistically significant difference between the study and control groups at T0& T1 (P=0.057 , 0.573). There is statistically significant decrease in mean osstel from T0 to T1 among control and study groups This finding is in contradictionwith other studies reported in the literature.Stability is the most determining factor of implant success. Implant stability occurs as a result of the process of osseointegration, which depends on the healing potential of the patient as well as on the implant design and surface characteristics. 18,19,20 Thesignificant difference in implant stability was observed within the 6 months' period in both groups, which can be attributed to two factors; an increased degree of osseointegration of implants or increased maturation of the surrounding grafted bone. Both of these factors occurnaturally with time.

MPM contains a considerable number of concentrated growth factors. Examples include EGF (Endothelial Growth
Factor), TGF-ß1 (Transforming Growth Factor Beta 1) and PDGF (platelet-derived growth factor). These factors, among others, enhance the differentiation of osteogenic cells and to significantly induce a greater amount of newly formed bone. 21,22 Choukroun et al. 23 reported that when the graft material is used along with PRF, there was 30% decrease in the healing time needed before dental implant placement in sinus floor augmentation. The writers recognized this healing accelerated to the platelets growth factors and fibrin network. This describes the graft volume stability after loading in the control group compared to the study group.
The added bone above implant protrusion to the ridge residual was measured by adding I P to R B H (B G = IP-RBH) at T0. In the control group, it measures from 3.5 mm to 6.2, with a mean of 3.12±0.94mm. In the study group, it ranged from 3.3 to 5.8mm with a mean of 4.26±0.97mm. It was observed a significant difference between the control and study groups (P=0.031).

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Both height and volume were used to assess the stability of the bone graft material. Itwasbecause the volume be a misleading parameter as the relationship between the implant apex and the level of the sinus floor is obscure. In our study, stability of the bone gained in terms of height and volume was significantly impacted by time since all cases have demonstrated a significant reduction in bone volume by the end of the follow-up period. It was in accordance with other studies reported in the literature. 24,25,26 In our study when comparing the two groups, A significant difference was found at either T1 or T2 (P=0.02 and 0.007) in bone resorption,in agreement with other research conducted by Chanavaz 27 reported that maxillary sinus pneumatization is encouraged by the positive pressure formation within the sinus of maxillary due to breathing.
The xenograft and MPM in the current study, regardingthe graft volume was calculated at T0. In the control group, it ranged from 2.01 to4.89 cm3 with a mean of 4.91 ± 0.85cm3. For the study group, it ranged from 2.34 to 5.21 cm3 with an average of 3.98±0.87cm3. It was observed a significant difference between the control and study groups (p=0.049), correspondingly. El Moheeb et al.reported that the possibility of raising that MPM inducesthe formation of new bone in procedures of sinus lifting when using as a grafted bone. 28 The xenograft granules display susceptible to growth factors, also tissue regeneration satisfactory effects on growth factor. Growth factors are unaffinitive to xenografts and xenogeneic bone graft materials resorb gradually. 29 The study by Umanjec-Korac et al. 30 reportthat maxillary sinus lifting with xenograft material showed 21% volume reduction when follow-up for 2-year in 29 patients. In another study by Sbordone et al. 31 reported 39.2% volume reduction at 6-year follow-up when used autogenous bone as a graft material in augmentation of maxillary sinus. All these studies exhibiting higher resorption rates compared to our study however, observation/reentry periods longer compared to our flow up 1 year. The graft materials show resorption slowly over time that positioned in the sinus.
The study reported by Smolka et al. 31 at 6 months follow up the percent average of autogenous bone volume reduction was 16% and at 1 year follow-up in the maxillary sinus lift show 19 %. In the study reported by Johansson et al. 32 Maxillary sinus augmentation shows 49.5% volume reduction with autogenous bone graft. Unpredictable resorption rate of xenograft bone in hard tissue augmentation as bone graft.
The study by Lee et al. 33 reported that the use of fibrin-enriched platelet glue, a comparable preparation to MPM, results in amount of bone gain statistically significant. An outcome that is in conflict with the results ofthis study. The reason is unclear but is the use of autogenous bone in Lee et al.'s study, which has osteogenic and osteoconductive potential.
For successful guided bone regeneration, The use of a barrier membrane to cover the bone window of the lateral approach of the sinus lift procedure has been traditionally used to aid in the prevention of graft displacement as well as to prevent soft tissue invasion into the graft material. 34 This situation is not the same when MPM is used. The fibrin content of the MPM appears to enclose the graft particles, prevents the invasion of soft tissues, and at the same time prevents the displacement of the graft particles.
MPM reduced dispersion of the bone graft particles, which may act as an aid in reducing the amount of the needed bone graft. The absence of collagen membrane reduce the cost of the grafting procedures.

Conclusion:-
MPM use as a grafting bone offer greater graft stability, handling, cost-effective source of growth factors and is easy to prepare and simultaneous implant placement in cases with a reduced residual bone height of 3mm can be successfully performed without significant impact on the implant survival rate.

Recommendation:-
A larger sample and a longer follow up period.