Clinical Research Directory

Is Cross-linked Hyaluronic Acid a Biologic Alternative for Alveolar Ridge Preservation?

Even after atraumatic tooth removal and/or immediate implant placement, some reduction of the alveolar ridge dimension is expected. To counteract (or limit) this reduction, alveolar ridge preservation technique (ARP) was developed. However, standard ARP techniques, such as grafting with bone substitutes, have some concerns, such as a long healing time prior to implant installation, residual graft particles, and often the need of re-grafting at implant installation. To overcome some of these limitations biologics have been discussed as an alternative approach, such as cross-linked hyaluronic acid (xHyA). However, whether the use of biologics only can achieve comparable results to the standard techniques, has yet to be answered. The aim of the present single-blind, randomized controlled clinical trial is to test non-inferiority in terms of mid-buccal alveolar ridge height resorption 4 months after ARP between 1) control/standard treatment (i.e., grafting with bone substitutes and socket seal) and 2) test treatment (i.e., xHyA applied with a collagen sponge and socket seal) at maxillary non-molar teeth. Forty-eight patients will be included and randomly assigned to one of the following 2 groups: 1) control group: standard ARP with deproteinized bovine bone material and covering of the socket with a free gingival graft (FGG) (n=24), 2) test group: application of xHyA soaked in a collagen sponge and covered by a FGG (n=24). The primary outcome parameter is the extent of mid-buccal alveolar ridge height resorption after 4 months, i.e., prior to implant installation, and the sample size calculation is based on a non-inferiority limit of 0.6 mm. The secondary outcome parameters are frequency of additional grafting at implant installation due to 1) a bony dehiscence or fenestration, 2) a thin buccal bone (\< 1.5 mm), or 3) contour improvement, cervical alveolar ridge width, alveolar ridge volume, histomorphometric assessment of alveolar ridge healing, feasibility of implant installation, aesthetic outcome parameters, patient reported outcome measures, changes in keratinized mucosa width, soft tissue healing, and assessment of postoperative complications. Patients will be followed up to 1 year after prosthetic restoration.

Peri-Implant Hard and Soft Tissue Changes After Immediate Implant Placement With Socket Shield and Immediate Restoration Versus Early Implant Placement in the Esthetic Zone

This randomized controlled clinical trial aims to compare peri-implant hard and soft tissue dimensional changes following immediate implant placement with the socket shield technique and immediate restoration versus early type II implant placement with contour graft in the esthetic zone. The primary outcome is the Pink Esthetic Score (PES), while secondary outcomes include mid-facial mucosal recession, radiographic vertical and horizontal buccal bone remodeling, and patient satisfaction after 12 months.

Efficacy Of Eggshell-Derived Nanohydroxyapatite Based Mineralized Plasmatic Matrix Versus Xenogeneic Based Mineralized Plasmatic Matrix in Posterior Mandibular Socket Preservation

After tooth extraction, the alveolar bone, which supports the teeth, undergoes a natural resorption process. This bone loss can be significant, especially in the first few months post-extraction, leading to a reduction in both bone height and width (Araújo et al ,. 2005) Generally, the goal of alveolar ridge preservation is to maximize bone formation while maintaining good soft tissue architecture, As socket preservation has proved high clinical efficacy in maintaining alveolar ridge high and width, there are many materials that have been proposed such as: autogenous bone grafts, allografts, xenografts, alloplasts, dentin graft and PRF. Unfortunately, the previously mentioned grafting material has several limitations have more such as high cost, biocompatibility, osteoinductive limitations and the need for a second surgical site. These limitations encouraged the researchers to test alternative materials and techniques to provide comparable or superior outcomes with fewer drawbacks. One of the newly introduced materials is eggshell derived nanohydroxyapatite (EnHA). Eggshell-derived nanohydroxyapatite (EnHa) represents a novel and potentially superior alternative due to its biocompatible, osteoconductive, and osteoinductive bone substitute. Preliminary studies suggest that this material. The synergistic effect of PRF when combined with various graft materials has also been extensively studied. when PR combined with bone grafting materials, it results in enhanced osteoconductive properties of graft materials and promotes efficient bone regeneration. (Yilmaz et al., 2017). However, up till now, there are no sufficient studies on the clinical efficacy of EnHA as a cheaper and readily available alternative which has superior clinical properties especially when combined with PRF compared to standard xenografts.

Vertical Ridge Augmentation Using Computer-guided Sandwich Osteotomy Technique

Researcher will introduce the trial to patients and provide full explanation of its aim and benefits in Arabic language. Patients will then be able to have an informed discussion with the researcher. Researcher will obtain written consent from patients willing to participate in the trial

Guided Bone Regeneration in Alveolar Socket

Following tooth extraction, volumetric changes in the soft and hard tissues of the extraction site are expected to occur with considerable resorption of the alveolar bone in both the vertical and the horizontal dimensions. These changes may complicate surgical implant placement and may also compromise the outcome of the prosthetic reconstruction. Various treatment approaches have been introduced aiming to preserve the dimensions of the alveolar ridge at the extraction site and facilitate optimal implant placement. This prospective randomized controlled trial aims to determine the efficacy of alveolar ridge preservation utilizing two different socket seal approaches compared to spontaneous healing to stabilize the blood clot within the postextraction socket. Thirty-six subjects will be randomly allocated into one of the three treatment groups. Group-A: Extraction of the tooth and suturing of the extraction socket with resorbable suture PGA 5/0. Group-B: Extraction of the tooth and placement of a Free Gingival Graft stabilized with resorbable suture PGA 5/0. Group-C: Extraction of the tooth and placement of the Polylactic-Glycolic Acid membrane stabilized with resorbable suture PGA 5/0. After the initial examination for screening, subjects will be assessed at baseline-extraction day- and after 1, 2, and 6 weeks, and 3 months. The changes of the alveolar crest will be determined in height and width, in addition to volumetric changes in the soft tissues, and the width of keratinized tissues. The wound healing process will be visually assessed.

Histological and Volumetric Evaluation of Customized Allograft Bone Blocks

Customized bone blocks need CBCT and digital software to design the block needed to rehabilitate. Some advantages are reduced surgical time and better adaptation of the graft, leading to less complications. Objectives: The primary aim of this study is to determine the bone regeneration capacity through a histological study and the bone volumetric changes of allograft bone blocks in the posterior site of the mandible. The secondary outcome will be to assess the survival and success rate of dental implants placed in the allograft regenerated area. Materials and Methods: After studying the CBCT to regenerate the posterior sites of the mandible, the investigators will design CAD/CAM freeze- dried bone allograft to fit exactly on the defect morphology that the patients present. A full thickness flap will be released to have a correct access of the defects. The sterile blocks have to fit perfectly on the defect and fixed by screws. Covered with resorbable membranes fixed with pines and suture. 4 months later, 2nd CBCTwill be performed. During the implant surgery, a bone trephine will be removed and sent into a Laboratory to make a histological study of the bone block for histomorphometry. After 3 months, second-stage surgery and healing caps will be placed if needed. Impressions will be taken 2 weeks after to perform the final crowns.

Vertical Ridge Augmentation Strategies

Guided Bone Regeneration (GBR) is an invaluable and beneficial surgical technique adopted when there is the need to augment an alveolar atrophy. Strong clinical and histologic evidence exists on the effectiveness and predictability of GBR in bone augmentation of ridge deficiencies. On the other hand, it is well known that GBR remains a challenge as in the most extreme cases, it is considered a highly technique-sensitive surgical procedure. Whilst there are numerous reviews which report the average incidence of complications in GBR, there is still insufficient evidence and manuscripts reporting a direct correlation between a specific biomaterial (membrane or scaffold) and observed complications. Only one recent systematic review and meta-analysis focused on wound healing complications following GBR for ridge augmentation procedures. Authors explored the complication rate based on the membrane type and on the timing of the first sign of soft tissue complications following bone augmentation procedures. They reported a complication rate of 17% of the overall soft tissue complications, including membrane exposure, soft tissue dehiscence, and acute infection (abscess). This estimate is consistent with that reported (12%) in a more recent systematic appraisal of the evidence on all types of complications in GBR (3). However, when horizontal augmentation procedures were reviewed, a higher rate (21%) of complications was reported within the first 18 months of a GBR procedure. This estimate was inclusive of all possible biologic complications following GBR whilst the rate of membrane exposure was of 23%. Vertical bone augmentation represents one of the most challenging bone regenerative procedures in surgical dentistry. This is because of the inherent difficulties of the surgical procedure and the high risk of complications. The primary aim of this procedure is to recreate alveolar bone in a vertical direction (without the support of any pre-existing walls) and enable recreation of a more favourable anatomy for the restoration of the edentulous site. Evidence on a variety of treatment options has been produced over the last 15 years including distraction osteogenesis, onlay bone grafting, and vertical ridge augmentation (VRA). Systematic reviews evaluating the efficacy of different surgical procedures for VRA either in a staged or a simultaneous fashion, reported a range of vertical bone gain of 2-8 mm. This gain was gradually lost (1.27 to 2.0mm) between 1 to 7 years post-surgery and a wide range of complications (0- 45.5%) has been reported. The aim of this study is to assess and compare incidence of complications and percentage of vertical bone gain when using four different barrier membranes in combination with 50/50 autogenous and xenogenous bone material in VRA procedures. Secondary aims will be to evaluate and compare early and late soft tissue wound healing, gingival microvasculature and structure, patient reported outcomes and the prevalence of need for further bone augmentation and need for soft tissue grafting. Additionally, this study will also aim to assess and compare histomorphometry and histochemistry analyses of core biopsies obtained before implant placement between the four different barrier membranes.