Horizontal Ridge Dimension Research Articles

The impact of membrane perforation and L-PRF for vertical ridge augmentation with a xenogeneic block graft: an experimental study in a canine model

ObjectivesThis study evaluated clinically and histologically the efficacy of modified perforated collagen membrane (PCM) and/or leukocyte- and platelet-rich fibrin (L-PRF) in combination with xenogeneic block bone graft in the vertical alveolar ridge augmentation.Materials and methodsSix adult mongrel dogs were enrolled in this randomized blinded study. After defect preparation, xenogeneic screw-fixed block graft was covered by an occlusive collagen membrane in group 1 that represented the control group (Block + CM). In group 2, L-PRF membrane was added first before top coverage by occlusive collagen membrane (Block + L-PRF + CM). Groups 3 (Block + PCM) and 4 (Block + L-PRF + PCM) were identical to the first two groups except that the occlusive collagen membrane was replaced by a perforated one. Following a healing period of 2 months, the dogs were submitted to the surgical reentry phase for clinical and histological evaluation.ResultsClinically, no significant differences were found among all groups regarding vertical and horizontal ridge dimensions (p = 0.155, 0.492, respectively). Histomorphometric analysis revealed that the percentage of the total bone area and mature bone was significantly higher in group 4 (69.36 ± 2.72, 33.11 ± 5.18) compared to the control group (59.17 ± 4.27, 21.94 ± 2.86) (p = 0. 027, p = 0.029).ConclusionThe use of xenogenic block grafts in combination with a double-layered perforated collagen L-PRF membrane in vertical ridge augmentation appeared to improve the inductive power of this challenging defect type.Clinical relevanceSize and number of perforations may affect the mechanical and handling properties of the membrane.

The Role of Different Healing Abutment Sizes in Tissue Volume Preservation of Molar Sockets After Immediate Tooth Extraction and Implant Placement: A Multicenter Clinical Study.

To evaluate the role of different healing abutment designs in compensating for the buccolingual volumetric tissue change that occurs following flapless single-tooth immediate extraction placement in the molar area. Patients in need of extraction and replacement of a first or second molar in the mandible or maxilla were consecutively recruited. Immediately after extraction and implant placement, an abutment was connected. Five different types of abutments were randomly selected to be used for each case. The study population was divided into five categories according to abutment design: 5-mm diameter healing abutment (group 1); 6-mm diameter healing abutment (group 2); 7.5-mm diameter healing abutment (group 3); provisional restoration (group 4); and customized healing abutment (group 5). The buccopalatal dimension (BPD) was measured on the study casts at 1, 3, and 5 mm apical to the free gingival margin, and horizontal volumetric changes were compared between baseline and 2, 4, and 6 months. A total of 267 implants were inserted in 246 patients. The breakdown of placed implants for each group was as follows: 67 implants in group 1; 64 in group 2; 71 in group 3; 33 in group 4; and 32 in group 5. Changes in the mean horizontal ridge dimension were as follows. After 6 months in group 1, BPD diminished at 1-, 3-, and 5-mm distance from the free gingival margin, respectively, by 4.21 ± 0.158, 3.38 ± 0. 178 and 2.35 ± 0.178 mm. In group 2, BPD diminished at 1-, 3-, and 5-mm distance from the free gingival margin, respectively, by 3.16 ± 0.198, 2.56 ± 0.198, and 1.62 ± 0.198 mm. In group 3, BPD diminished at 1-, 3-, and 5-mm distance from the free gingival margin, respectively, by 2.53 ± 0.138, 2.16 ± 0.144, and 1.56 ± 0.144 mm. In group 4, BPD diminished at 1-, 3-, and 5-mm distance from the free gingival margin, respectively, by 1.11 ± 0.179, 1.23 ± 0.179, and 1.12 ± 0.179 mm. In group 5, BPD diminished at 1-, 3-, and 5-mm distance from the free gingival margin, respectively, by 0.25 ± 0.225, 0.30 ± 0.225, and 0.19 ± 0.225 mm. Mixed-effect regression and post hoc means comparisons were used to model the impact of the restoration technique, height of measurement, and time on BPD using a significance reference level of .05. Statistical analysis showed that the type of abutment, the height of measurement, and the time significantly influenced the BPD and that there were complex interaction effects between these variables. The observed volumetric soft tissue changes in the 6-month short-term follow-up appeared to vary based on the use of different healing abutment sizes that were connected to implants placed immediately after tooth extraction in the molar area. In particular, the use of a customized healing abutment resulted in preservation of the original horizontal dimension of the molar soft tissue.

Split-Block Graft Versus Cortico-cancellous Block Graft for Horizontal Ridge Augmentation: Cone Beam Computed Tomography and Histomorphometric Study

Objective: The aim of this study was to compare the horizontal dimensional changes of split-bone block and cortico-cancellous block graft in horizontal ridge augmentation using Cone Beam Computed Tomography (CBCT). The quality of the regenerated bone in both groups was compared histologically and histomorphometrically. Material and methods: Twenty patients were randomly divided in two equal groups (n= 10): Split-bone block group which was harvested from the external oblique ridge or cortico-cancellous block graft group which was harvested from the mandibular symphysis. Pre-augmentation crestal ridge width was measured using bone caliper. CBCT scans were taken on the 2nd week and 4th month post-operatively to measure crestal and total horizontal ridge dimensions. A biopsy was collected from the regenerated ridge immediately before implant insertion on the 4th month post-operatively. Results: Pre-augmentation crestal bone widths of both groups were comparable (P= 0.870). On the 2nd week and 4th month post-operatively, split-bone block showed a significantly wider crestal (P= 0.028 and P= 0.001 respectively) and total horizontal ridge dimension (P= 0.025 and P= 0.002 respectively), and on the 4th month post-operatively, it showed significantly lesser resorption at crest (P= 0.040) and in total horizontal ridge dimension (P= 0.017) than cortico-cancellous block. Histologically, the regenerated bone quality was similar in both groups. Histomorphometric analysis showed a non-significant difference in percentage of mature (P= 0.365) and immature collagen (P= 0.531) between both groups. Conclusion: Split-bone block maintained a significantly wider ridge and experienced less resorption after 4 months than the cortico-cancellous block graft, with no difference in regenerated bone quality between both groups. Keywords Dental implants; CBCT; Cortico-cancellous block graft; Histomorphometric analysis; Split-bone block technique.

Efficacy of the Tent-Pole Technique in Horizontal Ridge Augmentation

Objective: To evaluate the efficacy of the technique for ridge augmentation prior to implant placement. Material and Methods: Six patients with nine sites presenting an initial ridge width of smaller than 4 mm were included in this study. The tent-pole technique (combination of osteosynthesis screws measuring 1.5 mm in diameter, ABBM, and resorbable collagen membrane) was applied at defect sites. After eight months of healing time, implants were placed in the treated sites. The primary outcomes (radiographic initial ridge width, re-entry ridge width, ridge width gain) were measured by cone-beam computed tomography in reference buccopalatal cross-sections and the secondary outcomes (clinical parameters) were recorded by a digital caliper at the first and second stages. Results: After grafting, the radiographic ridge width increased by 3.02 ± 1.11 mm (1.57-4.75 mm) at 2 mm below the crest and 3.32 ± 1.70 mm (0.23-5.66 mm) at 6 mm below the crest significantly (p< 0.05). For clinical results, the mean horizontal dimension gain was 3.21 ± 1.04 mm (1.83-4.57 mm), while the mean reduction in dimension was 0.38 ± 0.33 mm. These results were statistically significant (p<0.05). Uneventful healing and no infections or membrane exposure were recorded at all sites during the study process. Three of nine (33.33%) defect sites required additional bone grafting. Conclusion: The tent-pole technique is an effective method for increasing the horizontal ridge dimension, minimizing postoperative complications, and facilitating subsequent implant placement.

A New Surgical Protocol For Horizontal Ridge Augmentation: Simplified Apposition Technique. Human Histologic and Radiographic Analysis After 2.5 Years of Follow-Up, A Case Report

Following tooth extraction, alveolar ridge undergoes a physiological and inevitable remodeling process that could influence the prosthodontic rehabilitation. Therefore, augmentation of an insufficient bone volume is often indicated, although it remains a significant challenge in clinical practice. The aim of this case report was to scientifically validate a new minimally invasive surgery technique called “Simplified Apposition Technique” (S.A.T), which consists in the use of deproteinized bovine bone, human fibrin glue and collagen membrane in association with a post-extraction socket, in order to obtain an increase of the horizontal ridge dimension in the nearby atrophic bone crest. A 69-years-old man patient was enrolled in this study. The hopeless tooth 4.7 was extracted and the ridge reconstruction and the socket preservation were carried out following S.A.T. After 11 months, the formation of newly bone was evaluated through radiographic analysis (Cone Beam Computed Tomography, CBCT) comparing the status before and after surgery and at 2.5 years of follow-up. Simultaneously, an implant was placed in the regenerated site and the bone chips remaining in the drills were used for the histological evaluation. The CBCT revealed an increase of the bone crest width from 3.7 to 6.5 mm and, after 2.5 years of follow-up, the bone width has remained stable. The histological evaluation showed various stages of bone formation and maturation with a good integration of the regenerated area. According to these results, S.A.T can be considered a good surgical technique for horizontal ridge augmentation in the atrophic bone, near the extraction site.

Effect of Nano-hydroxyapatite and platelet-rich fibrin covered by the amniotic membrane on osseointegration after mandibular piezoelectric ridge splitting

ObjectiveThis study aimed to assess the clinical and radiographic findings obtained by using amniotic membrane (AM) to cover nano-hydroxyapatite (nHA) bone grafts coated with platelet-rich fibrin (PRF) and thereby evaluate the osseointegration of posterior mandibular implants inserted simultaneously during alveolar piezoelectric ridge splitting technique (RST). MethodsA prospective cohort study was implemented with thirty patients who had a narrow posterior mandibular alveolar ridge and required implant restoration. Patients were distributed randomly into three groups (group I treated by piezoelectric RST and immediate implant insertion, augmented by the nHA bone graft only; group II treated by piezoelectric RST augmented by nHA bone graft and covered by AM; while group III was treated by piezoelectric RST augmented with PRF and nHA graft and covered by AM). Patients were evaluated clinically to assess the implant stability quotient (ISQ) and radiographically to assess horizontal ridge dimension, crestal bone level (CBL), and bone densitometric (BD) parameters. ResultsISQ results showed a non-significant clinical difference between groups while CBL values showed a high statistically significant difference over the 12-month interval when comparing groups III and II with group I. BD outcomes showed statistically significant differences at all intervals in comparisons of group III with groups I and II. ConclusionsThe results of this study suggest that concomitant use of PRF with nHA graft covered with AM for augmentation around the dental implant in a narrow posterior mandible after piezoelectric alveolar ridge splitting accelerate osseointegration and significantly increase bone density around the osseointegrated implant and decrease bone resorption in comparison to that achieved with the graft alone.

Preservation of Peri-implant Hard Tissues Following Immediate Postextraction Implant Placement. Part I: Radiologic Evaluation.

Immediate implant placement may represent a possible treatment plan for single tooth restoration. This study evaluated the insertion of osseointegrated implants in intact fresh extraction sockets in the anterior maxilla. The bone-to-implant gap was accurately grafted with a bovine bone mineral prior to implant engagement, and an immediate screw-retained restoration was delivered. After 3 months, the provisional crown was replaced with the definitive ceramic crown. Marginal bone levels remained stable after 1 year. The horizontal ridge dimension was also evaluated at three levels using CBCT scans after 1 year. The horizontal width of the postextraction crest was well preserved independently from the thickness of the buccal bone plate at baseline.

Quantitative Assessment of the Edentulous Posterior Maxilla for Implant Therapy: A Retrospective Cone Beam Computed Tomographic Study.

Dimensional changes of the alveolar bone are often noted in horizontal and vertical planes as a sequel to tooth extraction, particularly in the maxillary posterior region due to alveolar bone resorption combined with pneumatization of the sinus. The aim of this retrospective study was to quantitatively assess the maxillary residual alveolar ridge using cone beam computed tomography (CBCT) scans. A total of 349 edentulous sites from 250 CBCTs were evaluated. The apico-coronal bone height and bucco-palatal crest width were measured in sagittal and coronal slices, respectively. Additionally, the obliqueness of the sinus floor at the edentulous sites was also evaluated. One hundred and twelve (55.45%) of the molar and 74 (54.42%) of the premolar sites had a horizontal ridge dimension < 6mm, whereas 137 (67.83%) of the molar and 61 (44.86%) of the premolar sites showed an apico-coronal height < 8mm. Furthermore, 183 (54.14%) of the evaluated sites had an oblique sinus floor morphology. Additional augmentative procedures are thus required in a high percentage of the population at the edentulous maxillary posterior site for rehabilitation using a standard dimension implant. This study stresses on the need for a three-dimensional CBCT prior to implant surgery for proper treatment planning.

Is Bone Graft or Guided Bone Regeneration Needed When Placing Immediate Dental Implants? A Systematic Review.

To systematically review the effect and type of bone graft and guided bone regeneration around immediate implants on hard and soft tissue changes. Three electronic databases were searched up to June 2015. Outcomes consisted of hard and soft tissue dimensional changes. Eight studies were included according to inclusion criteria. Immediate implants with bone grafting had superior soft tissue stability and preserved horizontal ridge dimension and buccal plate thickness, when compared to no grafting. The use of a barrier alone significantly decreased buccal plate resorption and the remaining defects around the implants, and the use of both bone graft and membrane aided in soft tissue preservation. The optimal type of bone graft material was a combination of cortical autogenous and synthetic particulate when compared to each separately, whereas no difference was found between demineralized allograft and hydroxyapatite in decreasing bone loss. Quantitative data analysis was not possible due to heterogeneity of the included studies. Further randomized clinical trials with homogenous samples and proper controls are needed to support the results of this report.

Platelet‐Rich Plasma–Assisted Guided Bone Regeneration for Ridge Augmentation: A Randomized, Controlled Clinical Trial

Platelet-rich plasma (PRP) contains a number of biologically active growth factors, and previous studies have reported conflicting ridge augmentation results. The primary aim of this randomized, controlled, masked, clinical trial was to determine if PRP combined with a rapidly resorbing cancellous allograft would enhance the regenerative result compared with an allograft without PRP. Thirty-two patients with an edentulous ridge defect were sequentially entered into the study; four were excluded from data analysis. Fourteen patients received a cancellous allograft (CAN group) and the other 14 received a cancellous allograft mixed with PRP (PRP group). All 28 grafted sites were covered with a resorbable polylactide membrane. After elevation of a full-thickness flap, horizontal ridge dimensions were measured with a digital caliper at the crest and 5 mm apical to the crest. Vertical ridge dimensions were measured from a tooth-supported stent. All sites were reentered at 4 months, and a trephine core was obtained for histologic analysis before implant placement. The crestal ridge width for the CAN group had a mean gain of 2.0 ± 1.2 mm, whereas the PRP group gained 2.9 ± 1.0, and the difference was statistically significant between groups (P <0.05). The percent vital bone was 36% ± 14% for the CAN group compared with 51% ± 15% for the PRP group and was statistically significant between groups (P <0.05). Loss of augmented ridge width was 34% ± 17% for the CAN group and 28% ± 17% for the PRP group (P >0.05). These clinical and histologic findings suggest that PRP enhanced bone regeneration and resulted in increased horizontal bone gain and percentage vital bone.

Flapless postextraction socket implant placement in the esthetic zone: part 1. The effect of bone grafting and/or provisional restoration on facial-palatal ridge dimensional change-a retrospective cohort study.

The dental literature has reported vertical soft tissue changes that can occur with immediate implant placement, bone grafting, and provisional restoration ranging from a gain or loss of 1.0 mm. However, little is known of the effects of facial-palatal collapse of the ridge due to these clinical procedures. Based upon treatment modalities rendered, an ensuing contour change can occur with significant negative esthetic consequences. The results of a retrospective clinical cohort study evaluating the change in horizontal ridge dimension associated with implant placement in anterior postextraction sockets are presented for four treatment groups: (1) group no BGPR = no bone graft and no provisional restoration; (2) group PR = no bone graft, provisional restoration; (3) group BG = bone graft, no provisional restoration; and (4) group BGPR = bone graft, provisional restoration. Bone grafting at the time of implant placement into the gap in combination with a contoured healing abutment or a provisional restoration resulted in the smallest amount of ridge contour change. Therefore, it is recommended to place a bone graft and contoured healing abutment or provisional restoration at the time of flapless postextraction socket implant placement.

Ridge Preservation Comparing Socket Allograft Alone to Socket Allograft Plus Facial Overlay Xenograft: A Clinical and Histologic Study in Humans

Previous studies of ridge preservation showed a loss of ≈18% or 1.5 mm of crestal ridge width in spite of treatment. The primary aim of this randomized, controlled, masked clinical trial is to compare a socket graft to the same treatment plus a buccal overlay graft, both with a polylactide membrane, to determine if loss of ridge width can be prevented by use of an overlay graft. Twelve patients who served as positive controls received an intrasocket mineralized cancellous allograft (socket group), and 12 patients received the same socket graft procedure plus buccal overlay cancellous xenograft (overlay group). Horizontal ridge dimensions were measured with a digital caliper, and vertical ridge changes were measured from a stent. Before implant placement, at 4 months, a trephine core was obtained for histologic analysis. The mean horizontal ridge width at the crest for the socket group decreased from 8.7 ± 1.0 to 7.1 ± 1.5 mm for a mean loss of 1.6 ± 0.8 mm (P <0.05), whereas the same measurement for the overlay group decreased from 8.4 ± 1.4 to 8.1 ± 1.4 mm for a mean loss of 0.3 ± 0.9 mm (P >0.05). The overlay group was significantly different from the socket group (P <0.05). Histologic analysis revealed that the socket group had 35% ± 16% vital bone, and the overlay group had 40% ± 16% (P >0.05). The overlay treatment significantly prevented loss of ridge width and preserved or augmented the buccal contour. The socket and overlay groups healed with a high percentage of vital bone.