Assessment of the Effect of Different Alveolar Ridge Augmentation Techniques on the Stability and Fit of Implant-supported Prostheses

Background Guided bone regeneration (GBR)is used to influence on stabilization of dental implants in patients with insufficient bone quantity and anatomical problems.But many studies using GBR resulted in divergent results according to the efficiency of new bone quantity formation and implant survival. This research aimed to study the effects of GBR on the increase of bone quantity and short-term stabilization of dental implants in patients with insufficient bone support. Methodology The study included 26 patientsthat underwent the procedure for 40 dental implants from September 2020 to September 2021. In each case, the vertical bone support was intraoperatively measured, through the MEDIDENT Italia paradontal millimetric probe (Medident Italia, Carpi, Italy). The vertical bone defect was considered when the mean vertical depth between the abutment junction and the marginal bone wasgreater than 1mm up to 8mm. In the group with the presence of the vertical bone defect, GBR technique was used duringthe procedure of dental implantsrealized with synthetic bone graft, resorbable membrane, and platelet-rich fibrin (PRF), and the group was considered the study (GBR) group. The group of patients with no vertical bone defects(less than 1mm) and no need for any GBR technique usewas considered the control (no-GBR) group. The bone support was evaluated again intraoperatively after six months in both groups when the healing abutmentswere positioned. The vertical bone defect for each group in baseline and after six months is presented as mean±SD and compared using a t-test. A t-test for Equality of Means was used to calculate the mean depth difference (MDD) between baseline and six months values in each group (GBR and no-GBR) and also between both groups. P-value ≤ 0.05 is considered statistically significant. Results Overall 40 dental implants were placed, 20 of them were included in the GBR group and 20 in the no-GBR group. In the GBR group, a statistically significant greater mean vertical bone defect in baseline (day 1), compared to the no-GBR group was found (-4.46±2.76 vs -0.27±0.22; MDD = -4.19 [-5.44 to -2.94] p<0.001). At six months of follow-up in the GBR group, a new bone around the implant was formed, presenting a significantly lower bone defect compared to the baseline measure (-0.39±0.43 vs -4.46±2.76; MDD = -4.07 mm [-5.37 to -2.78]p<0.001). In six months, no statistically significant difference between GBR and no-GBR group in bone support was found (-0.39±0.43 vs -0.27±0.22; MDD = -0.19 [-0.40 to -0.03] p=0.10). In each group, only one implant failure was observed. Conclusions The use of GBR showed an important reduction of vertical depth defect between healing abutment and marginal bone predisposing similarshort-term stability and survival of dental implants. The use of GBR techniques could be essential in the stabilization of dental implants in patients with insufficient bone support.

Clinical and 3-Dimensional Radiographic Evaluation of Autogenous Iliac Block Bone Grafting and Guided Bone Regeneration in Patients With Atrophic Maxilla

The placement of an implant into a fresh extraction socket has been identified as a reliable technique, allowing a reduction in the time needed for prosthetic rehabilitation. This treatment modality is widely reported in the scientific literature; however, the long-term outcomes and the need for guided bone regeneration (GBR) are still topics of debate. The aim of this prospective study is to evaluate the clinical and radiologic findings from the 10-year follow-up of immediately placed implants, with and without the GBR procedure. A total of 159 implants in 91 patients are included in this study; 101 implants required a GBR procedure simultaneously with placement. All implants were used to support a single crown restoration. The clinical/radiographic measurements were repeated each year up to the 10-year follow-up. At the 10-year follow-up visit, the papilla index and the apico-coronal location of mid-buccal soft tissue positions were recorded. The 10-year cumulative success rate was 91.8% (87.9% in the non-GBR group and 94.1% in the GBR group). The clinical attachment level (CAL) measurements were stable throughout the study, and 82% of the implants showed marginal bone loss (MBL) of 0.6 to 1.5 mm at the 10-year visit; moreover, these two parameters did not show significant differences between the GBR and non-GBR groups. Seventy percent of the implant sites showed acceptable outcomes in terms of interproximal papilla. The facial gingival level was more apical in the non-GBR group than in the GBR group (P <0.05). The present prospective clinical study shows that implants placed in fresh extraction sockets had a high cumulative success rate, namely 91.8% after 10 years. No differences were detected in survival and success rate of implants whether GBR procedures were performed or not. The CAL, MBL, and marginal level of soft tissue measurements were stable throughout the 10-year evaluation.

The aim of this study was to assess the success and survival rate of dental implants placed with simultaneous hard tissue grafting. All patients treated in Royal Dental Hospital of Melbourne who had implant placement with and without guided bone regeneration (GBR) procedures were identified. Seventy-three attended a follow-up appointment. These patients were examined recording probing depth, bleeding on probing, plaque accumulation and radiographic bone loss by one examiner. Clinical and radiographic findings were compared in grafted and non-grafted groups and also analysed for years in function. Approximately 50% of implants were placed simultaneous guided bone regeneration technique. In the majority of cases, defects were filled by deproteinized bovine bone mineral and covered with collagen membrane. The range of time in function was 20-88months with a mean 34.8 (±1.7). Seventy-nine per cent of the implants placed in anterior maxilla were placed with GBR, while only 18% in posterior mandible needed grafting procedure. The cumulative implant survival rates at the time of examination was 97.95% for both GBR and non-GBR group. The mean PPD, BOP, and Plaque index were not statistically significantly different in GBR vs. non-GBR groups two to seven years in function. However, bone loss is significantly less in GBR group 2-7years after function. The overall success rate was around 90% after 2-7years in function with the GBR group slightly less than the non-GBR group, but not statistically significant. For the subjects included in this retrospective study, the data demonstrate that GBR is a predictable procedure. The survival and success rates of the implants inserted with simultaneous GBR were similar, if slightly lower, to the non-grafted implants.

ObjectivesTo compare radiographic bone changes, following alveolar ridge preservation (ARP) using Guided Bone Regeneration (GBR), a Socket Seal (SS) technique or unassisted socket healing (Control).Material and methodsPatients requiring a single rooted tooth extraction in the anterior maxilla, were randomly allocated into: GBR, SS and Control groups (n= 14/). Cone Beam Computed Tomography (CBCT) images were recorded post‐extraction and at 4 months, the mid‐buccal and mid‐palatal alveolar ridge heights (BARH/PARH) were measured. The alveolar ridge width, cross‐sectional socket and alveolar‐process area changes, implant placement feasibility, requirement for bone augmentation and post‐surgical complications were also recorded.ResultsBARH and PARH was found to increase with the SS (0.65 mm ± 1.1/0.65 mm ± 1.42) techniques, stabilise with GBR (0.07 mm ± 0.83/0.86 mm ±1.37) and decrease in the Control (−0.52 mm ± 0.8/−0.43 mm ± 0.83). Statistically significance was found when comparing the GBR and SS BARH (p = .04/.005) and GBR PARH (p = .02) against the Control. GBR recorded the smallest reduction in alveolar ridge width (−2.17 mm ± 0.84), when compared to the Control (−2.3 mm ± 1.11) (p = .89). A mid‐socket cross‐sectional area reduction of 4% (−2.27 mm2 ± 11.89), 1% (−0.88 mm2 ± 15.48) and 13% (−6.93 mm2 ± 8.22) was found with GBR, SS and Control groups (GBR vs. Control p = .01). The equivalent alveolar process area reduction was 8% (−7.36 mm2 ± 10.45), 6% (−7 mm2 ± 18.97) and 11% (−11.32 mm2 ± 10.92). All groups supported implant placement, with bone dehiscence noted in 57% (n = 4), 64%(n = 7) and 85%(n = 12) of GBR, SS and Control cases (GBR vs. Control p = .03). GBR had a higher risk of swelling and mucosal colour change, with SS associated with graft sequestration and matrix breakdown.ConclusionGBR ARP was found to be more effective at reducing radiographic bone dimensional changes following tooth extraction.

To compare bone regeneration and dimensional alteration of alveolar ridge at intact and damaged extraction sockets after alveolar ridge preservation (ARP) and implant placement versus unassisted socket healing followed by guided bone regeneration (GBR) with simultaneous implant placement. In 6 beagle dogs, 3 types of extraction sockets in the mandible were created: (1) intact sockets, (2) 1-wall defect sockets and (3) 2-wall defect sockets. The sockets were allocated to undergo either (1) ARP and implant placement 8weeks later (ARP group) or (2) GBR with simultaneous implant placement after 8weeks of unassisted socket healing (GBR group). After an additional healing period of 8weeks, bone regeneration and dimensional changes were evaluated radiographically and histologically. GBR showed superior bone formation and greater bone gains compared to ARP, regardless of the initial extraction-socket configuration. Although ARP maintained the preexisting alveolar ridge dimensions, peri-implant bone defects were still detected at 8weeks of follow-up. Histomorphometric analyses confirmed that GBR increased dimensions of the alveolar ridge compared to baseline, and the augmentation and bone regeneration were greater with GBR than with ARP. Early implant placement with ARP can mitigate alveolar ridge changes in the narrow alveolar ridge. However, early implant placement with simultaneous GBR creates the conditions for enhanced bone regeneration around the implant and greater ridge augmentation compared to ARP, irrespective of the extraction-socket configuration.

To evaluate ridge preservation after ridge splitting with simultaneous implant placement and guided bone regeneration (GBR) in a miniature pig model. In miniature pigs, the mandibular premolars and first molars were extracted together with removal of the interdental and buccal bone. Three months later, ridge splitting and expansion of the buccal plate were performed with simultaneous placement of two titanium implants per quadrant. On the test side, access by a mucoperiosteal flap followed by GBR with a biphasic calcium phosphate and a collagen membrane was performed. On the contralateral control side, a mucosal flap (MF), leaving the periosteum attached to the buccal bone, was elevated. After healing periods of 6 and 12weeks, eight and four animals, respectively, were sacrificed for histological and histometric evaluation. In the MF group, all 16 implants were osseointegrated, while in the GBR group, one bone fracture occurred, and six of 16 implants were lost. After 6weeks, significantly higher bone crest levels were found for the GBR group than for the MF group both buccally and lingually (P<0.001), and buccal bone thickness was greater in the GBR group than in the MF group (P<0.001 at the implant shoulder [IS]). After 12weeks, bone was significantly higher in the GBR group compared to the MF group. Furthermore, buccal bone thickness in the GBR group was 0.93, 4.5, and 5.94mm at, and 2 and 4mm apical to the IS, respectively. The corresponding values in the MF group were greatly reduced (0, 0.21, and 2.56mm). Bone loss on the buccal side compared to the lingual side was significantly greater only in the MF group. In this ridge expansion model in miniature pigs, the buccal bone volume was significantly better preserved with GBR when compared to a mucosal access flap, provided that soft tissue healing occurred complication free.

When encountering a buccal bone defect during implant placement, guided bone regeneration (GBR) is a well-accepted method for bone reconstruction. However, it is still unclear if the esthetic and patient-reported outcomes are comparable to implants placed in native bone. The purpose of this prospective trial was to compare implants placed with a GBR procedure for a small (≤ 4 mm) buccal defect with implants placed completely in native bone (control). Patients were allocated to the GBR group or control group during implant placement in the esthetic zone. Implants were placed after at least 12 weeks of healing of the extraction sockets. A buccal bone defect of ≤ 4 mm resulted in allocation to the GBR group. Follow-up was performed until 12 months after loading. Outcome measurements were as follows: esthetic scores, patient-reported outcome measurements, implant survival and complications, clinical indices, and radiographic measurements. In total, 45 patients were included, of which 23 underwent a GBR procedure after implant placement, and in 22 patients no GBR was necessary. No significant differences in esthetic outcomes were seen between the two groups. At the final follow-up, a mean pink esthetic score (PES) of 7.8 (SD: 1.5) was seen for the GBR group and 8.4 (SD: 1.4) for the control group. Regarding the white esthetic score (WES), a mean of 9.1 (SD: 1.0) was found for both groups. Patients of both groups were equally satisfied with their mucosa and crown. A mean visual analog score (VAS) for the soft tissues of 8.6 (SD: 1.0) in the GBR group and 8.8 (SD: 0.9) for the control group was noted. A mean VAS of 9.2 (SD: 0.8) was noted for the crown in the GBR group and 8.6 (SD: 2.0) in the control group. Implant survival was 100%, and there were no significant differences in complications, plaque/bleeding/gingiva indices, width of attached mucosa, and marginal bone loss. Implants placed in the esthetic zone with GBR or complete native bone coverage showed successful esthetic outcomes and satisfied patients with predictable clinical and radiographic parameters after more than 1 year of loading. Within the limits of this study, GBR for a small buccal bone defect seems to be a reliable technique with good esthetics and patient-reported outcomes.

Purpose. Bone atrophy after tooth loss may leave insufficient bone for implant placement. We compared volumetric changes after autogenous ramus block bone grafting (RBG) or guided bone regeneration (GBR) in horizontally deficient maxilla before implant placement. Materials and Methods. In this retrospective study, volumetric changes at RBG or GBR graft sites were evaluated using cone-beam computed tomography. The primary outcome variable was the volumetric resorption rate. Secondary outcomes were bone gain, graft success, and implant insertion torque. Results. Twenty-four patients (28 grafted sites) were included (GBR, 15; RBG, 13). One patient (RBG) suffered mucosal dehiscence at the recipient site 6 weeks after surgery, which healed spontaneously. Mean volume reduction in the GBR and RBG groups was 12.48 ± 2.67% and 7.20 ± 1.40%, respectively. GBR resulted in significantly more bone resorption than RBG (P < 0.001). Mean horizontal bone gain and width after healing were significantly greater in the GBR than in the RBG group (P = 0.002 and 0.005, resp.). Implant torque was similar between groups (P > 0.05). Conclusions. Both RBG and GBR hard-tissue augmentation techniques provide adequate bone graft volume and stability for implant insertion. However, GBR causes greater resorption at maxillary augmented sites than RBG, which clinicians should consider during treatment planning.

Bone tissue engineering offers several advantages for repairing skeletal defects. In this study, we designed and fabricated a scaffold for bone tissue engineering in patients with horizontal alveolar defect. The items included in the fabrication of the scaffold were xenogenic bone graft, gelatin as a substrate to improve the physical integrity of scaffold, and simvastatin to stimulate osteogenesis (10 mg per 1 g of xenograft). Fourteen patients with a horizontal defect in the alveolar ridge were enrolled in the study. Seven patients underwent routinely guided bone regeneration (GBR) using xenogenic bone graft plus collagenous membrane, and seven patients were treated with the scaffolds. After four months of follow-up after surgery, both the scaffold and GBR groups were examined for changes in the width of alveolar ridge and histologically for the quantity of newly produced bone. The newly designed scaffold showed superior osteoconduction characteristics to routine GBR materials, which were used in this study. The difference in the quantity of the newly produced bone between the scaffold group and GBR group was significant and higher for the scaffold group. Regarding newly produced bone percentage, the scaffold group showed a mean of 20.93 and the GBR group presented a mean of 13.25% (P = 0.004). Also, the mean value for the duration of surgery for GBR was 45 minutes and for scaffold was 22 minutes, which was significantly lower in the scaffold group (P < 0.001). The newly designed scaffold is a suitable treatment modality for bone tissue engineering.

To evaluate the 1- to 5-year outcomes of dental implants placed with the tenting screw (TS) technique and to compare their clinical efficacy with conventional guided bone regeneration (GBR). This retrospective study involved implants placed with TS or conventional GBR technique. Horizontal and volumetric bone gains were evaluated by reconstructing cone-beam computed tomography (CBCT) data. Complications, biological parameters, esthetic scores, and patients' satisfaction were recorded. A total of 75 implants in 42 patients (20 defect sites in TS group and 22 in GBR group) were included in this study. With a 1- to 5-year follow-up, no implants failed, resulting in a 100% implant survival rate. After healing periods, the TS group demonstrated horizontal bone gains of 2.85 ± 1.42 mm, 3.37 ± 1.79 mm, and 3.27 ± 1.68 mm at 1, 3, and 5 mm below the implant shoulder, significantly exceeding the GBR group (p = 0.009, p = 0.002, p = 0.002, respectively). Consistently, three-dimensional volumetric bone resorption rates for the TS and GBR groups after healing periods were 16.5% and 29.3% (p < 0.001), increasing to 36.7% and 50.7% after follow-up periods (p < 0.001). The overall PPDs in the TS group were significantly smaller than those in the GBR group (2.50 (2.25, 2.50) mm vs. 2.50 (2.25, 2.75) mm, p = 0.038). No other significant differences were observed in terms of peri-implant soft tissue health, esthetics, and patients' satisfaction. Considering the superior bone augmentation outcomes and comparable peri-implant soft tissue health, esthetics, and patient satisfaction to the conventional GBR technique, the tenting screw technique emerges as a reliable treatment option for reconstructing atrophic alveolar ridges in the anterior maxilla.

Dimensional changes in the alveolar ridge after extraction often compromises on achieving optimal implant stability and placement of implants in the right prosthodontic positions. These situations demand augmentation of the residual ridge to achieve successful implant placement and long-term survival. A minimum amount of bone width and height is essential for the successful placement of implants. Unfavourable local conditions, due to atrophy, trauma and periodontal disease, may provide insufficient bone volume or an unfavourable interarch relationship, which does not allow correct and a prosthodontically guided positioning of dental implants. Guided bone regeneration, ridge splitting, block graft, or distraction osteogenesis have all been applied for this purpose and have shown some promising results. Nonetheless, autogenous block graft remains one of the main methods for reconstructing severely resorbed maxilla. These block grafts can be harvested from intraoral or extraoral sites. Significant amounts of autogenous bone can be procured from symphysis or ramus region of the mandible. The cortical grafts of this area provide predictable increase in bone volume with a short healing time and yield a highly dense osseous architecture for implant placement.This review discusses the use of autogenous block grafts and bovine bone allograft for predictable bone augmentation in atrophic ridges.

BackgroundImplant rehabilitation of posterior mandibular defects is frequently associated to a horizontal bone loss. There exist several regenerative techniques to supply this bone deficiency, one of which is the Periosteal Pocket Flap Technique (PPF) proposed by Steigmann et al. to treat small horizontal bone defects. The present study proposes a modification of this technique based on the concurrent use of PPF with the use of xenogeneic and autologous bone and Plasma Rich in Growth Factors (PRGF). The aim of this study is to evaluate clinical and radiographic outcomes of the PPF with the use of xenogeneic and autologous bone and PRGF in comparison with conventional Guided Bone Regeneration (GBR) procedures. MethodsNine patients were enroled in the study (7 women and 2 men, mean age: 53 ± 2.74 years) and allocated to PPF or GBR. In both groups implant placement was performed simultaneously to bone regeneration. Preoperative CBCT scans were performed for each patient. Surgical time and postoperative pain were recorded, as well as tissue healing. Moreover, horizontal bone gain (mm), graft surface area (mm2) and graft volume (mm3) were evaluated. ResultsNine surgeries were performed: 6 PPF and 3 GBR. Regarding clinical outcomes, operative time was significative greater in GBR group than in PPF group (51.67 ± 3.51 min vs. 37 ± 5.69 min; p = 0.008). Postoperative pain was higher in GBR compared to PPF (p = 0.011). Regarding radiographical results, there were not significant differences in horizontal bone gain (PPF: 9.43 ± 1.8 mm; GBR: 9.28 ± 0.42 mm), surface area (PPF: 693.33 ± 118.73 mm2; GBR: 655.61 ± 102.43 mm2), and volume (PPF: 394.97 ± 178.72 mm3; GBR: 261.66 ± 118 mm3) between groups. ConclusionsThis prospective study demonstrates that the combination of autograft/xenograft and PRGF in PPF technique is a simpler, cheaper, and faster technique than GBR technique for achieving moderate lateral bone augmentation in implant treatment. Future randomised clinical studies are needed to confirm the results.

Examine the histomorphometric bone composition, following alveolar ridge preservation techniques and unassisted socket healing. Forty-two patients (42) requiring a single rooted tooth extraction were randomly allocated into three groups (n = 14 per group): Group 1: Guided Bone Regeneration (GBR) using deproteinised bovine bone mineral (DBBM) and a porcine collagen membrane; Group 2: Socket Seal (SS) technique using DBBM and a porcine collagen matrix; Group 3: Unassisted socket healing (Control). Trephined bone biopsies were harvested following a 4-month healing period. Forty-two samples underwent Back-Scattered Electrons -Scanning Electron Microscopy (BSE-SEM) imaging, with 15 samples examined using Xray Micro-Tomography (XMT) (n = 6 for each GBR/SS and n = 3 Control). Images were analysed to determine the percentage (%) of connective tissue, new bone formation, residual DBBM particles and direct bone to DBBM particle contact (osseointegration). BSE-SEM analysis demonstrated that new bone formation was higher in the Control (45.89% ± 11.48) compared to both GBR (22.12% ± 12.7/p < .004) and SS (27.62% ± 17.76/p < .005) groups. The connective tissue percentage in GBR (49.72% ± 9), SS (47.81% ± 12.57) and Control (47.81% ± 12.57) groups was similar. GBR (28.17% ± 16.64) and SS (24.37% ± 18.61) groups had similar levels of residual DBBM particles. XMT volumetric analysis indicated a lower level of bone and DBBM particles in all test groups, when matched to the BSE-SEM area measurements. Osseointegration levels (DBBM graft and bone) were recorded at 35.66% (± 9.8) for GBR and 31.18% (± 19.38) for SS. GBR and SS ARP techniques presented with less bone formation when compared to unassisted healing. GBR had more direct contact/osseointegration between the DBBM particles and newly formed bone.

Onlay bone grafts have a bad reputation of resorption with loss of contour and volume. Rigid fixation reduces the incidence of resorption but does not prevent it. Literature shows reduction of resorption by applying guided bone regeneration (GBR) barriers and platelet-rich plasma (PRP). Investigating the effect of combining them together to reduce resorption was the aim of this study. This study included 4 groups: control group, GBR group, PRP group, and GBR + PRP group. Twenty rabbits were used (40 mandibular halves). Onlay bone grafts were fixed by titanium miniscrews in all groups. Computed tomography scans of harvested mandibles after euthanasia allowed calculations of bone graft volume and density. Onlay bone graft volumes in all experimental groups were significantly higher than in the control group. Volume maintenance in the GBR group was significantly higher than in the PRP group. There was no significant difference in the volume of onlay bone grafts between the group of combined GBR + PRP and GBR alone. It was concluded that, to maintain the volume of onlay bone grafts, either GBR or PRP can be added. Combining them did not add any advantage over the GBR alone.