Reconstruction of the severely resorbed maxilla with autogenous bone, platelet-rich plasma, and implants: 1-year results of a controlled prospective 5-year study

Assessment of the efficacy of autologous blood preparations in maxillary sinus floor elevation surgery: a systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the efficacy of autologous blood preparations, namely Platelet-Rich Plasma (PRP), Platelet-Rich Fibrin (PRF), and Concentrated Growth Factor (CGF), in maxillary sinus floor elevation surgery. The focus was on their impact on new bone formation, maxillary sinus floor height, and soft tissue healing.

METHODS

A systematic search was conducted across PubMed/MEDLINE, Web of Science, Embase, and Scopus databases up to April 2024. This systematic review included both randomized clinical trials (RCTs) and controlled clinical trials (CCTs) that evaluated the efficacy of autologous blood preparations in maxillary sinus floor elevation surgery. The primary outcomes measured were the percentage of new bone formation, maxillary sinus floor height, and he percentage of soft tissue area. Data from the selected studies were extracted and analyzed to determine the impact of autologous blood preparations on these outcomes. The risk of bias was assessed using Cochrane's risk of bias tool and ROBINS-I, and meta-analyses were performed using Review Manager 5.4 software to calculate effect sizes and integrate results from multiple studies.

RESULTS

Among the 507 screened articles, 30 studies met the inclusion criteria. The results indicated that the application of PRP significantly increased new bone formation during maxillary sinus floor elevation surgery (primary outcome, MD = 4.40, CI = 0.37 to 8.44, P = 0.03), as well as improving maxillary sinus floor height elevation (secondary outcome, MD = 1.00, CI = 0.78 to 1.23, P < 0.00001). The absence of PRP during surgery had a statistically significant effect on the percentage of soft tissue area (secondary outcome, MD= -5.25, CI= -7.29 to 3.20, P < 0.00001). However, based on the research findings, PRF did not show significant effects on enhancing new bone formation, maxillary sinus floor height elevation, and promoting soft tissue regeneration.

CONCLUSIONS

PRP demonstrates efficacy in maxillary sinus floor elevation surgery by enhancing new bone formation and increasing sinus height. Further studies are needed to validate the outcomes of PRF and CGF.

Comparison of the Photofunctionalization and Platelet-Rich Plasma in the Immediate Implants

Introduction

Many adjuvant methods have been researched to enhance the immediate implant success in the recent times. The study's goal was to compare the aesthetic and biological results of immediate dental implants in the aesthetic zone to standard tapered root form implants that had not undergone pre-treatment with platelet-rich plasma or photofunctionalization.

Materials and Methods

The study used a randomized controlled trial as its design. Ninety subjects were chosen at random and placed into three groups: a control group, a case group, and a group that needed replacement of their maxillary anterior teeth right away following extraction. The interventional groups received the "Platelet-Rich Plasma (PRP)" or "Photofunctionalization (PF)" group before the implant placement. After the delayed loading approach, the prosthesis was given after 6 months. At the second and fourth weeks, as well as 2, 4, 6, and 12 months (P 0.05), follow-up was conducted. The success and survival rate, aesthetic, and biological outcomes were assessed. One-way ANOVA was used to compare outcomes, and repeated-measures ANOVA was used to assess intragroup variations over baseline and follow-up.

Results

The distal, mesial, and mean marginal bone loss as well as the aesthetic scores for pink and white did not differ significantly between groups. The implant stability however was significantly higher in the PF and PRP groups as compared to the controls. A single implant failed in all the three groups. The success percentage was similar for all the groups.

Conclusion

The stability of immediate dental implants pre-treated with PRP or PF differed statistically significantly than the subjects in the control group, while other parameters remained the similar between the groups.

Bone-Regenerative Ability of Platelet-Rich Plasma Following Sinus Augmentation with Anorganic Bovine Bone: A Systematic Review with Meta-Analysis

BACKGROUND

The objective of this systematic review is to assess the effect of the adjuvant use of platelet-rich plasma (PRP) and its type on new bone formation by anorganic bovine bone during maxillary sinus floor augmentation procedure.

METHODS

PubMed, Cochrane Central Register of Controlled Trials, and Ovid databases were searched for relevant studies published up to 16 September 2021. Randomized clinical trials (RCTs) and non-randomized controlled clinical trials (CCTs) that reported data on the new bone formation (measured by histomorphometric analysis) were considered. Risk of bias and quality assessment of included studies were evaluated following the Cochrane Handbook for Systematic Reviews of Interventions and the Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I) tool. Strength of evidence was assessed following the approach of the Agency for Healthcare Research and Quality (AHRQ) through its evidence-based practice center (AHRQ EPC). The meta-analysis was based on the primary outcome of newly formed bone, for which the standard mean difference was calculated.

RESULTS

After the application of eligibility criteria, six clinical trials (three RCTs and three CCTs) covering 85 maxillary sinus floor elevation procedures were included. The pooled new bone formation value for PRP was 1.67 (95% CI: -0.15 to 3.49; I2: 86%), indicating the absence of significant effect. Plasma rich in growth factors (PRGF) was the pure PRP tested in five of the included studies. When sub-group (type of PRP) meta-analysis was performed, significantly higher new bone formation was observed in the PRGF group [2.85 (95% CI: 0.07 to 5.64; I2: 88%)] in comparison to the control group.

CONCLUSIONS

A beneficial effect on new bone formation after maxillary sinus floor elevation can be obtained when anorganic bovine bone is mixed with PRGF.

EFFECT OF AUTOGENOUS BONE GRAFT SITE ON DENTAL IMPLANT SURVIVAL AND DONOR SITE COMPLICATIONS: A SYSTEMATIC REVIEW AND META-ANALYSIS

OBJECTIVES

This systematic review and meta-analysis was undertaken to answer the following focus questions: Is the implant survival in augmented bone utilizing iliac crest bone grafts the same as while using intraoral autologous bone grafts? Is the incidence of postoperative donor site complications the same when using iliac crest bone grafts as opposed to intraoral grafts?

METHODS

Systematic searches of electronic databases (PubMed, Embase, CENTRAL) were performed to identify studies which reported on implant survival and postoperative complications for dental implants placed in grafted partially/completely edentulous human jaws. Studies were included if: they reported on 2-piece micro-rough surface root form dental implants placed in bone-augmented completely or partially edentulous human jaws, and the jaws must have been augmented with autologous bone graft materials. Time and nature of postoperative complications must have been reported. Two investigators performed data extraction and a Cohen's unweighted kappa was calculated for inter-investigator reliability. A meta-analysis was performed for the extracted data on implant survival rate in both iliac crest grafts and intra-oral grafts. A qualitative analysis was performed on the information extracted on graft donor site complications. Quality assessment of the included studies were done using the Cochrane collaboration tool and the Newcastle-Ottawa scales.

RESULTS

A total of 23 studies were included in the final analysis. The calculated kappa ranged between 0.77-0.89 for the literature search and identification process. Fourteen studies were included with data on implant survival including five randomized controlled clinical trials. The meta-analysis of included studies revealed that the implant survival rate of dental implants placed in jaws augmented with iliac crest grafts was lower than those placed in jaws augmented with intra-oral bone grafts at 6-months [ICG = 95.8% IOG = 98.4%; P < .001], 12-months [ICG = 97.0%, IOG = 98.4%; P < .001], 24-months [ICG = 85.9%, IOG = 98.2%; P < .001], 60-months [ICG = 90.0%, IOG = 91.5%; P < .001], and at 120-months [ICG = 88.8%, IOG = 95.2%; P < .001] follow-up periods. Iliac crest grafts were also frequently associated with donor site complications including pain / discomfort, gait disturbance, and sensory disturbance.

CONCLUSIONS

This systematic review and meta-analysis demonstrates that implant survival is consistently higher in bone harvested from intraoral sites compared to iliac crest grafts. Donor site complications seemed to be a frequent finding with iliac crest grafts and mental grafts.

FUNDING

None.

REGISTRATION

The review protocol was registered with PROSPERO: International prospective register of systematic reviews (CRD42021283738).

Dual-Function Semaphorin 4D Released by Platelets: Suppression of Osteoblastogenesis and Promotion of Osteoclastogenesis

Effects of the antiosteoblastogenesis factor Semaphorin 4D (Sema4D), expressed by thrombin-activated platelets (TPs), on osteoblastogenesis, as well as osteoclastogenesis, were investigated in vitro. Intact platelets released both Sema4D and IGF-1. However, in response to stimulation with thrombin, platelets upregulated the release of Sema4D, but not IGF-1. Anti-Sema4D-neutralizing monoclonal antibody (mAb) upregulated TP-mediated osteoblastogenesis in MC3T3-E1 osteoblast precursors. MC3T3-E1 cells exposed to TPs induced phosphorylation of Akt and ERK further upregulated by the addition of anti-sema4D-mAb, suggesting the suppressive effects of TP-expressing Sema4D on osteoblastogenesis. On the other hand, TPs promoted RANKL-mediated osteoclastogenesis in the primary culture of bone-marrow-derived mononuclear cells (BMMCs). Among the known three receptors of Sema4D, including Plexin B1, Plexin B2 and CD72, little Plexin B2 was detected, and no Plexin B1 was detected, but a high level of CD72 mRNA was detected in RANKL-stimulated BMMCs by qPCR. Both anti-Sema4D-mAb and anti-CD72-mAb suppressed RANKL-induced osteoclast formation and bone resorptive activity, suggesting that Sema4D released by TPs promotes osteoclastogenesis via ligation to a CD72 receptor. This study demonstrated that Sema4D released by TPs suppresses osteogenic activity and promotes osteoclastogenesis, suggesting the novel property of platelets in bone-remodeling processes.

Survival Rates of Dental Implants in Autogenous and Allogeneic Bone Blocks: A Systematic Review

Background and Objectives: Preliminary studies emphasize the similar performance of autogenous bone blocks (AUBBs) and allogeneic bone blocks (ALBBs) in pre-implant surgery; however, most of these studies include limited subjects or hold a low level of evidence. The purpose of this review is to test the hypothesis of indifferent implant survival rates (ISRs) in AUBB and ALBB and determine the impact of various material-, surgery- and patient-related confounders and predictors. Materials and Methods: The national library of medicine (MEDLINE), Excerpta Medica database (EMBASE) and Cochrane Central Register of Controlled Trials (CENTRAL) were screened for studies reporting the ISRs of implants placed in AUBB and ALBB with ≥10 participants followed for ≥12 months from January 1995 to November 2021. The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias was assessed via several scoring tools, dependent on the study design. Means of sub-entities were presented as violin plots. Results: An electronic data search resulted in the identification of 9233 articles, of which 100 were included in the quantitative analysis. No significant difference (p = 0.54) was found between the ISR of AUBB (96.23 ± 5.27%; range: 75% to 100%; 2195 subjects, 6861 implants) and that of ALBB (97.66 ± 2.68%; range: 90.1% to 100%; 1202 subjects, 3434 implants). The ISR in AUBB was increased in blocks from intraoral as compared to extraoral donor sites (p = 0.0003), partially edentulous as compared to totally edentulous (p = 0.0002), as well as in patients younger than 45 as compared to those older (p = 0.044), cortical as compared to cortico-cancellous blocks (p = 0.005) and in delayed implantations within three months as compared to immediate implantations (p = 0.018). The ISR of ALBB was significantly increased in processed as compared to fresh-frozen ALBB (p = 0.004), but also in horizontal as compared to vertical augmentations (p = 0.009). Conclusions: The present findings widely emphasize the feasibility of achieving similar ISRs with AUBB and ALBB applied for pre-implant bone grafting. ISRs were negatively affected in sub-entities linked to more extensive augmentation procedures such as bone donor site and dentition status. The inclusion and pooling of literature with a low level of evidence, the absence of randomized controlled clinical trials (RCTs) comparing AUBB and ALBB and the limited count of comparative studies with short follow-ups increases the risk of bias and complicates data interpretation. Consequently, further long-term comparative studies are needed.

Cell and Cell Free Therapies in Osteoarthritis

Osteoarthritis (OA) is the most common articular disease in adults and has a current prevalence of 12% in the population over 65 years old. This chronic disease causes damage to articular cartilage and synovial joints, causing pain and leading to a negative impact on patients' function, decreasing quality of life. There are many limitations regarding OA conventional therapies-pharmacological therapy can cause gastrointestinal, renal, and cardiac adverse effects, and some of them could even be a threat to life. On the other hand, surgical options, such as microfracture, have been used for the last 20 years, but hyaline cartilage has a limited regeneration capacity. In recent years, the interest in new therapies, such as cell-based and cell-free therapies, has been considerably increasing. The purpose of this review is to describe and compare bioregenerative therapies' efficacy for OA, with particular emphasis on the use of mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP). In OA, these therapies might be an alternative and less invasive treatment than surgery, and a more effective option than conventional therapies.

Lateral Alveolar Ridge Augmentation with an Autogenous Bone Block Graft Alone with or without Barrier Membrane Coverage: a Systematic Review and Meta-Analysis

Objectives

To test the hypothesis of no difference in implant treatment outcome following lateral alveolar ridge augmentation with autogenous bone block graft with or without barrier membrane coverage.

Material and Methods

PubMed (MEDLINE), Embase and Cochrane library search in combination with a hand-search of relevant journals was conducted. Human studies published in English until the 8^th of February 2021 were included. Randomised controlled trials with an observation period longer than three months were included. Survival of implants and suprastructures were considered as primary outcomes measures, whereas peri-implant marginal bone loss, dimensional changes of the alveolar ridge, bone regeneration, patient-reported outcome measures, biological and mechanical complications were secondary outcome measures, as evaluated by descriptive statistics and meta-analysis including 95% confidence interval (CI).

Results

Electronic search and hand-searching resulted in 411 entries. Five randomised controlled trials characterised by low or high risk of bias fulfilled inclusion criteria. No statistically significant difference between the two treatment modalities was observed in any of the outcome measures. However, barrier membrane coverage was associated with a non-significant gain in alveolar ridge width of 0.5 mm (95% CI = -0.1 to 1.1) and diminished resorption of -0.9 mm (95% CI = -2.4 to 0.7) compared with no barrier membrane coverage.

Conclusions

Comparable implant treatment outcomes were revealed following lateral alveolar ridge augmentation with autogenous bone block graft alone with or without barrier membrane coverage. However, postoperative dimensional changes of the augmented seems to be diminished with the use of barrier membrane coverage as evaluated by two-dimensional linear measurements.

Biological and esthetic outcome of immediate dental implant with the adjunct pretreatment of immediate implants with platelet-rich plasma or photofunctionalization: A randomized controlled trial

Aim

The purpose of the study was to assess biological and esthetic outcomes of immediate dental implant in esthetic zone with the adjunct pretreatment of immediate implants with photofunctionalization or platelet-rich plasma in comparison to standard tapered root form implant without pretreatment.

Settings and Design

Patients visiting department of Prosthodontics of a tertiary care health Institution. Design of the study was randomized controlled trial.

Materials and Methods

Ninety subjects who required replacement of maxillary anterior teeth immediately after extraction were selected and randomly divided into three groups: control group and two case groups. Two case groups were treated with immediate implants with pretreatment with Photofunctionalization (PF group) or platelet-rich plasma (PRP group). Delayed loading protocol was followed with prosthesis given after 6 months. Follow-up was performed at 2nd and 4th weeks and 2, 4, 6, and 12 months (P < 0.05). Biological outcomes (mean marginal bone loss, implant stability), esthetic outcome (pink esthetic score and white esthetic score), and success and survival rate were evaluated.

Statistical Analysis Used

Outcomes were compared using one-way ANOVA, while intragroup changes with baseline and follow up were assesed using repeated-measures ANOVA. Statistical analyses were performed using Statistical Package for Social Sciences version 25.0 (SPSS Inc., Chicago, IL, USA). The level of significance was set at <.05.

Results

Mean marginal bone loss was not significantly different in PF group and PRP group than the control group. PF group and PRP group showed significantly greater implant stability as compared to the control group. Pink and white esthetic scores were not significantly different among groups.

Conclusion

Pretreatment of commercial dental implants with PF or PRP exhibited a statistically significant difference in implant stability but not with other outcomes.

Review of bone graft and implant survival rate : A comparison between autogenous bone block versus guided bone regeneration

In oral surgery, there is a multitude of bone augmentation techniques and biomaterials choices. Autogenous bone is considered the gold standard in bone graft due to its biocompatibility, osteoinduction, osteoconduction and osteogenic properties. An alternative to autogenous bone grafting is the guided bone regeneration technique. The objective of this review is to compare the results of implant survival in an autogenous bone block compared to those in a graft by guided bone regeneration. An electronic search in PubMed Central's database was performed. The search strategy was limited to human studies, full-text English or French articles published from 1996 until may 2020. All types of autogenous bone block and guided bone regeneration techniques were evaluated. In total 16 articles were included. The overall survival rate of implants was 97,9% in autogenous block (range: 95.6-100%) and 98,5% (range: 94.4-100%) in GBR. The implant survival rate does not differ between the two types of bone graft in a guided bone regeneration or in an autogenous bone block. They are comparable to the current literature data. The choice of an appropriate treatment is based on several factors related to the patient and the anatomy of the defects.

Non-grafted versus grafted sinus lift procedures for implantation in the atrophic maxilla: a systematic review and meta-analysis of randomized controlled trials

The aim of this systematic review and meta-analysis was to critically evaluate the currently existing clinical evidence on the efficacy of graftless maxillary sinus membrane elevation for implantation in the atrophic posterior maxilla. A search protocol without limitations to November 2020 was followed by two independent researchers. Randomized controlled trials using the lateral window approach for graftless sinus membrane elevation were included. Uncontrolled, retrospective, non-comparative studies, case reports, and experimental studies in animals or cadavers were excluded. The search identified 2777 studies. Critical selection by two independent researchers then led to the inclusion of a total of nine studies. A risk of bias assessment was applied using the revised Cochrane risk-of-bias tool for randomized trials. A meta-analysis was conducted for seven studies. Results showed a high overall implant survival rate in both the graftless and bone-grafted sinus lift groups (97.92% and 98.73%, respectively). The graftless sinus lift group showed a significantly lower vertical bone height gain, with a mean difference of -1.73mm (P=0.01), and a significantly lower bone density, with a mean difference of -94.7 HU (P<0.001). The implant stability quotient values did not differ significantly between the test and control groups (P=0.07).

Bone demineralization improves onlay graft consolidation: A histological study in rat calvaria

BACKGROUND

Previous data suggest that bone demineralization may promote bone graft consolidation as well as proliferation and differentiation of pre-osteoblasts, but the biological mechanisms involved in this process need to be clarified. This study investigated the effects of bone demineralization with citric acid (CA) and tetracycline (TCN) on the repair of onlay bone grafts.

METHODS

Onlay bone grafts were performed on the calvaria of 126 Wistar rats. The contacting surfaces between bone graft and receptor bone bed were demineralized for 15, 30, and 60 seconds with TCN (50 mg/mL), or 10% CA, (pH 1), constituting the following test groups (n = 18): TCN15, TCN30, TCN60, CA15, CA30, and CA60. Control grafts (C) were performed without demineralization (n = 18). After 7, 30, and 60 days, biopsies were obtained for quantitative and qualitative histological analysis (a = 6).

RESULTS

Demineralization accelerated the bone repair early from 7 days of healing. Higher percentage area of newly formed bone was observed in CA15 and TCN60 groups when compared to C in all evaluation periods (P = 0.02). At 30 days, C specimens had lower percentage of consolidated surfaces than TCN60, TCN30 and CA15 (P = 0.0015). At 60 days, CA15, CA60, and TCN60 presented bone surfaces almost completely filled by newly formed bone, against about 75% in C specimens (P = 0.0015).

CONCLUSIONS

Both CA and TCN were effective in accelerating osteogenesis at the interface between bone grafts and receptor bone beds, especially when applied for 15 seconds and 60 seconds, respectively.

UV-Mediated Photofunctionalization of Dental Implant: A Seven-Year Results of a Prospective Study

Our objective was to evaluate the seven-year results of photofunctionalized implants placed in regular, complex, and cancer-related cases. This study was a prospective, single-center study. Photofunctionalization was performed immediately prior to implantation with Ultraviolet (UV) light for 15 minutes. The success rate of each patient group and the influential factors on implant failure were analyzed. Seventy implants in 16 patients were included. Four implants were left submerged (sleep). The seven-year success rate of 30 implants in regular cases and 21 implants in complex cases was 100%. The success rate of 15 implants in cancer-related cases was 22.2%, in which implants were placed in resection or reconstructed sites with or without pre- or postoperative radiation history. Implant stability quotient (ISQ) values increased at second-stage surgery by 3.2 in regular cases and by 21.9 in complex cases, while it decreased by −3.5 in cancer cases. Multivariate analysis indicated that bone quality, location, and cancer resection significantly influenced implant failure. A very reliable seven-year success rate was obtained by UV-photofunctionalized implants in regular and complex cases, even with significant site-development procedures. However, the success rate in cancer cases was significantly and remarkably lower, suggesting remaining challenges of pathophysiologically compromised conditions, such as bone resection, segmental defect, and radiation.

Role of Platelet-Rich Fibrin (PRF) and Platelet-Rich Plasma (PRP) in Oro-Facial Tissue Regeneration: A Narrative Review

Background and Aim:

Regeneration potential of platelet-rich fibrin (PRF) and platelet-rich plasma (PRP) in oral tissues regeneration has revolutionized the clinical dentistry in recent years. The in vivo and in vitro research on PRP and PRF has opened a new avenue in the dentistry and medicinal care. It is a minimally invasive and cost-effective technique that will raise the bar of clinical dentistry. The results presently documented are overwhelming; the potential to use PRF and PRP in the clinical dentistry have improved dental quality, satisfaction, and clinical outcome. The aim of the review was to recapitulate the regenerative and healing potential of platelet extracts in different disciplines of clinical dentistry.

Materials and Methods:

The attempt was to answer the following question: what are the various clinical oral health applications for PRF and PRP available in the published literature? The dual functions (tissue sealants and drug delivery systems to carry biomolecules and chemotactic growth factors) have helped the practitioners to treat the complicated oral conditions and tissues regeneration. The PRF and plasma has emerged as a powerful therapeutic tool for management of soft and hard tissue healing and regenerative procedures, including implant osseointegration. More research is mandatory to use these platelets concentrate to their full potential in various clinical applications.

Conclusion:

PRF is an emerging therapeutic tool in the management of oral soft and hard tissue healing and regenerative procedures.

Long-Term Influence of Platelet-Rich Plasma (PRP) on Dental Implants after Maxillary Augmentation: Retrospective Clinical and Radiological Outcomes of a Randomized Controlled Clinical Trial

: The long-term clinical and radiological outcomes of dental implants inserted in augmented bone treated with platelet-rich plasma (PRP) has not been well addressed in the literature yet. This study is based on a collection of patients from a randomized controlled trial (RCT) that did not report any short-term positive effects of PRP on bone healing after sinus lift surgery using autologous iliac crest bone graft. This study aimed to evaluate the long-term impact of PRP regarding clinical and radiological outcomes on the inserted implants in the previous RCT. For this evaluation, we considered the following variables: plaque index, probing depth, bleeding index, mobility grade, Periotest® values, and radiological bone loss. Out of 53 patients (n = 306 implants) included in the previous study we were able to reinvestigate 37 patients (n = 210 implants) in two centers (31 in Giessen, Germany and 6 in Erlangen, Germany). Clinical and radiographic parameters suggested overall healthy conditions of the peri-implant tissue. The PRP-group and the control group did not differ significantly in the majority of the parameters. The overall evaluation showed that result data of the PRP-group was inferior to the control group in 64 percent of the evaluated parameters. The present study cannot provide evidence of a positive effect of PRP on the long-term implant clinical and radiological outcomes. In fact, a tendency towards inferior long-term results in the PRP-group was detected without reaching a significant threshold. Further controlled trials need to be conducted to investigate this correlation.

Eight to eleven-year follow-up of immediately loaded implants placed in edentulous maxillae with compromised bone volume and poor bone quality: A prospective cohort study

BACKGROUND

There is a lack of long-term evaluations of immediately loaded implants in patients with compromised maxillary bone.

PURPOSE

To evaluate long-term survival and success of immediately loaded implants in subjects with poor maxillary bone quality and volume.

MATERIAL AND METHODS

Follow-up was performed on subjects who received six implants loaded within 24 hours with screw-retained fixed prostheses. Twenty-five subjects with limited bone (Lekholm and Zarb, quantity 3 and 4, and quality C and D) were included in the study. Nineteen participated in the radiographic examination and of these 17 participated in the clinical examination at the last visit. Evaluations of marginal bone loss were performed at 1, 3, 5, and 8-11 years. The last clinical examination included removal of the prosthesis followed by registration of: plaque, pus, pocket depth, bleeding upon probing, mobility, and percussion testing.

RESULTS

The mean follow-up was 9 years and 2 months (101-131 months) after surgery and showed a cumulative implant survival rate of 81.9% and success rate of 74.7%. Mean marginal bone loss was 1.29 mm (SD 2.47 mm range 0-11 mm) with a mean pocket depth of 3.1 mm (SD 2.4 mm, range 1.5-13.5 mm). 42.5% of the implants showed plaque retention and 72.2% showed bleeding on probing.

CONCLUSION

This nonaugmenting immediate loaded implant protocol for maxillary edentulous patients is a satisfactory solution for selected patients.

Reduction in post extraction waiting period for dental implant patients using plasma rich in growth factors: an in vivo study using cone-beam computed tomography

Objectives

This study examined the effects of plasma-rich growth factors (PRGF) on accelerating bone regeneration/repair in fresh extraction sockets, and determined the quality and quantity of bone by assessing the bone density using cone-beam computed tomography (CBCT).

Materials and Methods

Twenty patients, who had undergone bilateral extractions, were included in this study. In one extraction socket, PRGF was used and covered with an autologous fibrin plug. Nothing was used in the opposite side extraction socket. Thirteen weeks post extraction, the level of bone regeneration was evaluated on both sides with CBCT.

Results

At the end of the study, the mean bone density according to the Hounsfield units (HU) in the control group and PRGF group was 500.05 HU (type III bone type) and 647.95 HU (type II bone type), respectively.

Conclusion

This study recommends the use of PRGF in post extraction sites to accelerate the rate of bone regeneration and improve the quality of regenerated bone. The technique to process PRGF was simple compared to previously mentioned techniques used for platelet-rich plasma (PRP) preparation. PRP preparation requires a two-cycle centrifugation procedure, leading to a longer processing time.

Design of a Randomized Controlled Clinical Study of tissue-engineered osteogenic materials using bone marrow-derived mesenchymal cells for Maxillomandibular bone defects in Japan: the TEOM study protocol

Background

Maxillomandibular bone defects arise from maxillofacial injury or tumor/cyst removal. While the standard therapy for bone regeneration is transplantation with autologous bone or artificial bone, these therapies are still unsatisfactory. Autologous bone harvesting is invasive and occasionally absorbed at the implanted site. The artificial bone takes a long time to ossify and it often gets infected. Therefore, we have focused on regenerative therapy consisting of autologous bone marrow-derived mesenchymal cells (BM-MSCs), which decreases the burden on patients. Based on our previous research in patients with maxillomandibular bone defects or alveolar bone atrophy using a mixture of BM-MSCs, platelet-rich plasma (PRP), thrombin, and calcium, we confirmed the efficacy and acceptable safety profile of this treatment. In this investigator-initiated clinical study (the TEOM study), we intended to add β-tricalcium phosphate (β-TCP) owing to large defect with patients. The TEOM study aimed to evaluate the efficacy and safety of bone regeneration using mixtures of BM-MSCs in patients with bone defects resulting from maxillofacial injury, and tumor/cyst removal in the maxillomandibular region.

Methods

The TEOM study is an open-label, single-center, randomized controlled study involving a total of 83 segments by the Fédération Dentaire Internationale numbering system in maxillomandibular bone defects that comprise over 1/3 of the maxillomandibular area with a remaining bone height of ≤10 mm. The primary endpoint is rate of procedure sites with successful bone regeneration defined as a computed tomography (CT) value of more than 400 and a bone height of more than 10 mm. Our specific hypothesis is that the number of required regions was calculated assuming that the rate of procedure sites with successful bone regeneration is similar and the non-inferiority margin is 15.0%.

Discussion

The TEOM study is the first randomized controlled study of regenerative treatment using BM-MSCs for large maxillomandibular bone defects. We will evaluate the efficacy and safety in this study to provide an exploratory basis for the necessity of BM-MSCs for these patients.

Trial registration

This trial was registered at the University Hospital Medical information Network Clinical Trials Registry (UMIN-CTR Unique ID: UMIN000020398; Registration Date: Jan 15, 2016; URL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000016543).

The use of platelet-rich plasma to enhance the outcomes of implant therapy: A systematic review

Objective

To assess the effect of platelet‐rich plasma (PRP) on implant dentistry. The primary focused question was as follows: What are the clinical, histological, and radiographic outcomes of PRP administration for bone regeneration and implant therapy?

Methods

A literature search was conducted involving three databases: MEDLINE, EMBASE and Cochrane database followed by a hand search of relevant scientific journals. Human studies using PRP for bone regeneration and implant therapy were considered and articles published up to December 31, 2017 were included. Eligible studies were selected based on the inclusion criteria, and quality assessments were conducted.

Results

In total, out from the 9,497 titles meeting the original search criteria, 22 fulfilled the inclusion criteria and were chosen for data extraction. Among them were 15 randomized controlled trials (RCT) and seven controlled clinical trials (CCT). Overall, the risk of bias was moderate to high. A total of seven studies showed superior outcomes when PRP was added during sinus floor elevation and five showed no superior outcome. Three studies found a significant advantage of PRP for alveolar bone regeneration and another three studies for soft tissue healing. Three studies reported on beneficial effects of PRP directly during implant placement while another study failed to find significant differences. Due to the heterogeneity of study designs, no meta‐analysis could be performed.

Summary and Conclusions

Despite the lack of consistent evidence supporting the clinical benefit of PRP in healthy patients, PRP might have a positive effect on wound healing and bone regeneration in compromised patients.

Biofunctionalization of porcine-derived collagen matrix using enamel matrix derivative and platelet-rich fibrin: influence on mature endothelial cell characteristics in vitro

OBJECTIVES

The present study evaluated the effect of an enamel matrix derivative (EMD) and platelet-rich fibrin (PRF)-modified porcine-derived collagen matrix (PDCM) on human umbilical vein endothelial cells (HUVEC) in vitro.

MATERIALS AND METHODS

PDCM (mucoderm®) was prepared to 6 mm (±0.1 mm) diameter discs. PDCM samples were incubated with either EMD, PRF, or control solutions for 100 min at 4 °C before the experiments. Cell-inducing properties of test materials on HUVEC cells were tested with cell proliferation assays (MTT, PrestoBlue®), a cytotoxicity assay (ToxiLight®), a Boyden chamber migration assay, and a cell attachment assay. Scanning electron microscopy (SEM) imaging was performed to determine the surface and the architecture of the modified matrices.

RESULTS

Cell proliferation was elevated in the EMD and PRF groups compared with control (p each ≤0.046). PRF modification increased HUVEC migration ability by 8-fold compared with both control and EMD groups (p each <0.001). Both treatments significantly promoted the cell attachment of HUVEC to PDCM, as assessed by direct cell counts on the matrices (p each <0.001).

CONCLUSIONS

HUVEC cell characteristics were overall improved by EMD- and PRF- modified PDCM. Adsorbed bioactive molecules to the PDCM surface may have contributed to a more preferable environment to surrounding cells.

CLINICAL RELEVANCE

The results may give evidence that PDCM modification with EMD or PRF, respectively, might be a useful approach to improve clinical outcomes, to prevent inflammatory reactions and wound-healing disturbances, and to expand the clinical application area of PDCM.

Autologous blood preparations rich in platelets, fibrin and growth factors

OBJECTIVES

Bone regeneration is often needed prior to dental implant treatment due to the lack of adequate quantity and quality after infectious diseases. The greatest regenerative power was obtained with autologous tissue, primarily the bone alive, taken from the same site or adjacent sites, up to the use centrifugation of blood with the selection of the parts with the greatest potential regenerative. In fact, various techniques and technologies were chronologically successive to cope with an ever better preparation of these concentrates of blood. Our aim is to review these advances and discuss the ways in which platelet concentrates may provide such unexpected beneficial therapeutic effects.

METHODS

The research has been carried out in the MEDLINE and Cochrane Central Register of Controlled Trials database by choosing keywords as "platelet rich plasma", "platelet rich fibrin", "platelet growth factors", and "bone regeneration" and "dentistry".

RESULTS

Autologous platelet rich plasma is a safe and low cost procedure to deliver growth factors for bone and soft tissue healing.

CONCLUSION

The great heterogeneity of clinical outcomes can be explained by the different PRP products with qualitative and quantitative difference among substance.

Effectiveness of platelet-rich plasma as an adjunctive material to bone graft: a systematic review and meta-analysis of randomized controlled clinical trials

The use of platelet-rich plasma (PRP) has become a strategic therapy in tissue regeneration medicine. PRP represents a good source of growth factors. Due to this property, it has been considered a reliable adjunctive material in bone augmentation procedures, such as the sinus lift technique. The aim of this review was to assess the scientific evidence on the effectiveness of PRP as an adjunctive material in the sinus floor elevation technique. The following databases were searched for relevant published studies: Medline, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, CINAHL, Science Direct, ISI Web of Knowledge, and SCOPUS. Only randomized controlled clinical trials comparing a group receiving PRP as an adjunctive material to a control group without PRP, involving adult human subjects (age >18 years) with no systemic disease, were included. Of the studies identified, only one reported a significant difference in bone augmentation in favour of the adjunctive use of PRP, while four studies did not find any significant difference. None of the studies included reported a significant difference in the implant survival rate. Further randomized clinical trials are needed to clarify the effectiveness of adjunctive PRP.

Effects of platelet-rich plasma in association with bone grafts in maxillary sinus augmentation: a systematic review and meta-analysis

This systematic review evaluated the effect on bone formation and implant survival of combining platelet-rich plasma (PRP) with bone grafts in maxillary augmentation. A comprehensive review of articles listed in the PubMed/MEDLINE, Embase, and Cochrane Library databases covering the period January 2000 to January 2015 was performed. The meta-analysis was based on bone formation for which the mean difference (MD, in millimetres) was calculated. Implant survival was assessed as a dichotomous outcome and evaluated using the risk ratio (RR) with 95% confidence interval (CI). The search identified 3303 references. After inclusion and exclusion criteria were applied, 17 studies were selected for qualitative analysis and 13 for quantitative analysis. A total of 369 patients (mean age 51.67 years) and 621 maxillary sinus augmentations were evaluated. After the data analysis, additional analyses were performed of the implant stability quotient, marginal bone loss, and alveolar bone height measured by MD. The results showed no significant difference in implant stability (P=0.32, MD 1.00, 95% CI -0.98 to 2.98), marginal bone loss (P=0.31, MD 0.06, 95% CI -0.05 to 0.16), alveolar bone height (P=0.10, MD -0.72, 95% CI -1.59 to 0.14), implant survival (P=0.22, RR 1.95, 95% CI 0.67-5.69), or bone formation (P=0.81, MD -0.63, 95% CI -5.91 to 4.65). In conclusion, the meta-analysis indicates no influence of PRP with bone graft on bone formation and implant survival in maxillary sinus augmentation.

Bone marrow aspirate concentrate and platelet-rich plasma enhanced bone healing in distraction osteogenesis of the tibia

BACKGROUND

During lower limb lengthening, poor bone regeneration is a devastating complication. Several local or systemic applications have been used to promote osteogenesis, and biologic stimulations are gaining attention, but their utility has not been proven in this setting.

QUESTIONS/PURPOSES

In patients undergoing bilateral tibial lengthening, we compared those receiving an osteotomy site injection of autologous bone marrow aspirate concentrate (BMAC) plus platelet-rich plasma (PRP) with those not receiving such an injection in terms of external fixator index (time in external fixation divided by amount of lengthening), full weightbearing index (time until a patient was permitted to do full weightbearing divided by amount of lengthening), four cortical healing indexes (time until each cortical union divided by amount of lengthening), and callus shape and type.

METHODS

Twenty-two patients (44 tibias) undergoing bilateral tibial lengthening enrolled in this randomized trial. Two patients were excluded, one due to insufficient radiographic evaluation and one who was lost to followup, leaving 20 patients (40 segments) for inclusion. Ten patients (20 segments) received BMAC combined with PRP injection (treatment group) and 10 patients (20 segments) received no injection (control group). All patients underwent stature lengthening for familial short stature with the lengthening over nail technique. Autologous BMAC combined with PRP was injected at the tibial osteotomy site at the end of the index surgery. Mean distraction rates were similar between groups (0.75 mm/day in the treatment group versus 0.72 mm/day in the control group; p = 0.24). Full weightbearing was permitted when we observed radiographic evidence of healing at two cortices; this assessment was made by the surgeon who was blinded to the treatment each patient received. Minimum followup was 24 months (mean, 28 months; range, 24-34 months).

RESULTS

There was no difference in mean external fixator index between groups. However, mean cortical healing indexes (anterior/posterior/medial/lateral) were 1.14/0.81/0.96/0.88 months/cm in the treatment group and 1.47/1.26/1.42/1.22 months/cm in the control group (all p < 0.001), showing faster healing in the treatment group at each cortex. Full weightbearing was permitted earlier in the treatment group than in the control group (index: 0.99 months/cm and 1.38 months/cm, respectively, p < 0.001). Callus shape and type were not different between groups.

CONCLUSIONS

Autologous BMAC combined with PRP injection at the osteotomy site helped improve bone healing in distraction osteogenesis of the tibia, although the effect size was small.

LEVEL OF EVIDENCE

Level I, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Recent Trends in Sinus Lift Surgery and Their Clinical Implications

BACKGROUND

Sinus lift procedures are used to allow residual bone to accommodate functional implants in atrophic posterior maxilla. Numerous anatomical and surgical advancements in sinus lift surgery are still inspiring clinicians.

PURPOSE

The purpose of this study was to describe the recent trends in sinus lift surgery focusing on implant survival, bone grafting, anatomical and surgical considerations, and their clinical implications on the practice of implant dentistry in atrophic posterior maxilla.

MATERIALS AND METHODS

We performed an extensive search in MEDLINE, Embase, Scopus, Web of Science, Trip, Cochrane Oral Health Group's Trials Register, Cochrane Central Register of Controlled Trials, and ProQuest Dissertations & Theses. Articles were critically reviewed to determine the level of evidence as per the Canadian Task Force on Preventive Health Care.

RESULTS

Comprehensive assessment of sinus septa, sinus pathology, and bone quality and quantity using three-dimensional cone beam computed tomography radiographs is important before placing implants in posterior maxilla. With a residual bone height of less than 5 mm, the survival rate of implant decreases substantially. Lateral window approach can increase the vertical bone height to greater than 9 mm, while osteotome approach can increase this height from 3 to 9 mm. The perforation of Schneiderian membrane doubles the risk for the incidence of sinusitis or infection. The use of piezoelectric surgery allows adequate sinus lift while protecting soft tissues and minimizing patient discomfort.

CONCLUSIONS

Although both osteotome and lateral window procedures can help clinicians in overcoming the challenges of placing implants in atrophic posterior maxilla, pre-implant residual bone height is crucial in determining the survival of these implants. Future research directions should consider study designs grounded on longitudinal randomized controlled trials of large sample size.

Relationship between the CT Value and Cortical Bone Thickness at Implant Recipient Sites and Primary Implant Stability with Comparison of Different Implant Types

BACKGROUND

Studies have shown that bone quality at the implant recipient site can influence primary stability.

PURPOSE

The aims of this study were to explore the quantitative estimation of the primary stability of implants preoperatively using CT values and to examine the effect of different implant designs with recommended socket preparation on primary stability.

MATERIALS AND METHODS

Forty-four fresh porcine femoral heads were prepared. The bone surrounding implant sockets was preoperatively evaluated by helical CT. Forty-four implants (φ 4.3 × 10 mm), 22 straight and 22 tapered, were placed according to the manufacturer's instructions. The insertion torque value (ITV), implant stability quotient (ISQ), and removal torque value (RTV) were recorded as indicators of primary implant stability.

RESULTS

Significant correlations and linear relationships were found between the CT value and ITV, ISQ, and RTV for both straight and tapered implants (Spearman's correlation coefficient, p < .001; linear regression analysis, p < .01). Tapered implants had a significantly higher ITV than straight implants (analysis of covariance, p < .01).

CONCLUSIONS

Obtained results suggest that the primary stability of implants could be quantitatively estimated using the CT value preoperatively, indicating the CT value of bone surrounding an implant can contribute considerably to implant planning and design choice in clinical situations.

Comparative study of alveolar bone height and implant survival rate between autogenous bone mixed with platelet rich plasma versus venous blood for maxillary sinus lift augmentation procedure

AIM AND OBJECTIVES

The aim of this study was to evaluate changes in alveolar bone height by means of radiographic examination and Straumann implant survival rate following maxillary sinus lift augmentation using autogenous bone in combination with platelet rich plasma (PRP) versus venous blood (VB).

METHODS

Fifty patients requiring sinus lift augmentation procedure included in the study were divided into two groups (n = 25). During the procedure the sub antral sinus cavity was augmented using autogenous bone taken from mandibular ramus area and mixed with PRP in one group and autogenous bone mixed with VB in the other group. Orthopantomograms were taken preoperatively, immediate, at 6 months and 1 year postoperatively. Height of alveolar bone at the site of sinus augmentation was measured on the radiographs. One hundred and twenty-one Straumann dental implants were placed after healing period.

RESULTS

Age of the patients in the study groups ranged from 36 to 69 years. Differences in mean values of bone height measurements recorded in the PRP series revealed significant differences among the three subgroups (P = 0.001). Significant differences were noted between immediate postop and 6 month (P < 0.01), immediate postop and year (P < 0.01). In the VB series also significant differences were revealed among the three subgroups (P = 0.0280). Significant differences were noted between immediate postop and 6 month (P < 0.05). Comparison of results of subgroups of the two series at the three intervals revealed significant differences at 'immediate postop' values (P = 0.0002) and 'sixmon' values (P = 0.0435). Differences between 'year' values were not significant. Two implants were lost in PRP group.

CONCLUSION

The results of this limited study reveals that both groups recorded a good increase in the alveolar bone height after sinus augmentation and showed no significant differences between these groups when compared to each other at 1 year postoperatively. When both sub groups compared with immediate postop to year, PRP group showed significant difference and blood group showed no significant difference.

Vector-controlled alveolar distraction osteogenesis using an implant-fixed provisional prosthesis: a case report

This is a case report of anterosuperior alveolar distraction using an implant-fixed provisional prosthesis. Osteotomy and placement of a distraction device were performed in a healthy 69-year-old woman. To avoid lingual inclination during the distraction period, the device's rod was buried in the labial side of a provisional prosthesis supported by posterior implants. The mandibular bone was obliquely distracted by 0.3 mm every 2 days. Implant insertion was performed, and a good prognosis was anticipated. Inclination is thought to be caused by soft tissue on the lingual side. Many reports propose methods to avoid inclination, but these methods require established support from the teeth and cannot be adapted for an edentulous case. The method reported here is useful for distraction osteogenesis because it can be adapted for edentulous cases.

In vivo comparison of the bone regeneration capability of human bone marrow concentrates vs. platelet-rich plasma

BACKGROUND

Bone marrow aspirate concentrate (BMAC) including high densities of stem cells and progenitor cells may possess a stronger bone regenerative capability compared with Platelet-rich plasma (PRP), which contains enriched growth factors. The objective of this study was to evaluate the effects of human BMAC and PRP in combination with β-tricalcium phosphate (β-TCP) on promoting initial bone augmentation in an immunodeficient mouse model.

METHODOLOGY/PRINCIPAL FINDINGS

BMAC and PRP were concentrated with an automated blood separator from the bone marrow and peripheral blood aspirates. β-TCP particles were employed as a scaffold to carry cells. After cell counting and FACS characterization, three groups of nude mice (BMAC+TCP, PRP+TCP, and a TCP control) were implanted with graft materials for onlay placement on the cranium. Samples were harvested after 4 weeks, and serial sections were prepared. We observed the new bone on light microscopy and performed histomorphometric analysis. After centrifugation, the concentrations of nucleated cells and platelets in BMAC were increased by factors of 2.8 ± 0.8 and 5.3 ± 2.4, respectively, whereas leucocytes and platelets in PRP were increased by factors of 4.1 ± 1.8 and 4.4 ± 1.9, respectively. The concentrations of CD34-, CD271-, CD90-, CD105-, and CD146-positive cells were markedly increased in both BMAC and PRP. The percentage of new bone in the BMAC group (7.6 ± 3.9%) and the PRP group (7.2 ± 3.8%) were significantly higher than that of TCP group (2.7 ± 1.4%). Significantly more bone cells in the new bone occurred in sites transplanted with BMAC (552 ± 257) and PRP (491 ± 211) compared to TCP alone (187 ± 94). But the difference between the treatment groups was not significant.

CONCLUSIONS/SIGNIFICANCE

Both human BMACs and PRP may provide therapeutic benefits in bone tissue engineering applications. These fractions possess a similar ability to enhance early-phase bone regeneration.

Correlation of platelet growth factor release in jawbone defect repair--a study in the dog mandible

BACKGROUND

Platelet concentrate/platelet-rich plasma (PRP) has been studied extensively in various experimental models and there is some agreement among workers to its early effect in bone regeneration and healing. We have earlier showed in vitro that titanium in whole blood activates the thrombogenic response to a higher degree than PRP and that a fluoridated test surface augmented the effect compared with control.

PURPOSE

We designed this study to evaluate the effect of PRP and whole blood on bone regeneration in a dog implant defect model and, in addition, the effect of a test surface modified in hydrofluoric acid. A correlation attempt between platelet count, release of growth factors, and bone regeneration was made.

MATERIALS AND METHODS

Six dogs were used and simultaneously with the experimental surgery and implant installation, autologous PRP was prepared. Defects were prepared (6 mm in diameter and 5 mm deep), and implants were installed (TiO2 gritblasted and hydrofluoric acid treated [test] or TiO2 gritblasted [control], 5 mm in diameter and 9 mm long) in defects filled with either PRP or whole blood. Randomization of sides between PRP and whole blood, and sites for test and control implants were made. Blood samples were collected from PRP and whole blood. The dogs were killed after 5 weeks of healing, and samples with implants and surrounding bone were collected and processed for analysis. Enzyme linked immunosorbent assays were used for detection of growth factors in PRP.

RESULTS

The mean increase of platelet count was 424% in PRP. A correlation for platelet counts and transforming growth factor β was found in each dog (r(2) = 0.857). Approximately 50% of the region of interest (ROI) in the defects was filled with new bone after 5 weeks. No difference could be observed in ROI by using PRP or whole blood in the defects regarding new bone formation, bone in contact with implant, or distance to first bone contact. However, the fluoridated implants exhibited more new bone formation (p = .03) compared with control, regardless of comparing PRP or whole blood, and also displayed a shorter distance from first bone contact to the margin of the bone envelope (p = .05).

CONCLUSIONS

Platelet concentrate/PRP failed to show more new bone regeneration in a peri-implant defect model compared with whole blood. Implants treated with hydrofluoric acid displayed higher percentages of bone fill in the defect.

Particulate vs. block bone grafts: three-dimensional changes in graft volume after reconstruction of the atrophic maxilla, a 2-year radiographic follow-up

BACKGROUND

Extensive alveolar bone resorption in the maxilla limits the possibility of successful placement and osseointegration of endosseous implants for future prosthetic rehabilitation. Autogenous bone from the iliac crest may be used as lateral onlays in the atrophic maxilla, both as block and particulate bone. To our knowledge, there is no three-dimensional 2-year follow-up study measuring the volumetric reduction of the augmented areas comparing particulate and block bone grafts.

PURPOSE

The aim of this study was to conduct a radiographic 2-year follow-up study, using computed tomographic (CT) images in order to evaluate and compare the extent of bone graft resorption in the frontal maxillae augmented by particulate (test) and block bone (control).

MATERIAL AND METHODS

Eleven patients treated with iliac bone grafts and oral implants in the maxilla were followed with CT examinations directly post grafting and after 2 years.

RESULT

The volumetric changes after 6 months were extensive. Additionally, the changes in particulate bone tended to be larger after 2 years compared to block bone, using this protocol. However, the difference was not statistically significant.

CONCLUSION

The present follow-up study showed that there is radiographically complete integration and embedding of implants installed in grafted bone despite extensive initial graft resorption. There was no significant difference in the amount of volumetric reduction between particulate bone and block bone grafts.

Maxillary autogenous bone grafting

Reconstruction of the atrophic maxilla for dental implant placement has many unique considerations. There are several methods available to augment the atrophic maxilla. Of these, autogenous bone grafting offers a well-proven predictable method for ridge augmentation and defect repair for dental implant placement. There are several advantages of using autogenous bone grafts. This article primarily focuses on the use of autogenous onlay bone grafts to reconstruct the atrophic maxilla.

Marginal bone-level alterations at implants installed in block versus particulate onlay bone grafts mixed with platelet-rich plasma in atrophic maxilla. a prospective 5-year follow-up study of 15 patients

BACKGROUND

Extensive atrophy of the alveolar process may require a bone-grafting procedure prior to implant treatment. Autogenous bone grafts from the iliac crest, used as onlay block and particulate bone, have been used together with sinus-lift procedure in order to rehabilitate patients with extremely resorbed maxillae. However, there are to our knowledge no 5-year follow-up studies evaluating the extent of bone-level change in patients treated with respectively block and particulate autogenous bone grafts.

PURPOSE

The purpose of this prospective clinical study was to conduct a 5-year follow-up analysis with focus on bone-level alteration in block versus particulate onlay bone grafts.

MATERIAL AND METHODS

Fifteen out of originally 19 patients who were treated with iliac bone grafts and oral implants in the maxilla have been followed through the first 5 postoperative years. In a first study conducted on 19 patients, the role of platelet-rich plasma in conjunction with autogenous bone was evaluated. In this 5-year follow-up study, the marginal bone alterations have been documented at base line, 1 year and 5 years of loading to the nearest 0,1 mm at mesial and distal surfaces of the implants. Two implants were installed on each side of the midline in either block or particulate bone grafts giving test and control sides in each patient. Additionally, two implants on each side were installed in residual bone/grafted sinus floor.

RESULT

Marginal bone alteration in the anterior maxilla appeared larger at the side augmented by block bone at baseline, and after 1 and 5 years of loading, but the change was not statistically significant. Moreover, there was a significantly higher degree of marginal alteration during the first year of loading, compared with the examinations after 5 years.

CONCLUSION

The present follow-up study showed that there is no significant difference in the extension of resorption between block- and particulate autogenous bone grafts over a 5-year period. Most of the resorption occurred during the first year in function.

Onlay and inlay bone grafts with platelet-rich plasma: histologic evaluations from human biopsies

PURPOSE

The aim of the present study was to histomorphometrically evaluate biopsies from 1) sinus inlay bone grafts prepared with or without platelet-rich plasma (PRP) and 2) onlay bone grafts in the anterior maxilla with particulate bone and PRP or block bone without PRP after 3 months.

MATERIALS AND METHODS

Biopsies were retrieved with a trephine drill, and samples were processed in laboratories to result in nondecalcified cut and ground sections. Light microscopic measurements of total bone area, new bone, number of vessels, and vessel area were performed at 3 regions in each sample. Calculations of ratios of new bone to total bone and vessel area to total area were performed.

RESULTS

There was a tendency toward higher mean values for total bone area percentage and area of newly formed bone in the PRP-treated inlay biopsies. However, there was no measurable effect on vessel formation in the PRP-treated inlay samples compared with untreated inlay samples. Particulate and PRP-treated onlay bone biopsies showed higher mean values in all measured parameters compared with block bone samples; however, no differences were statistically significant.

CONCLUSION

PRP treatment may favor bone formation in grafted bone, and further research is needed to describe the outcome of PRP treatment and grafting techniques in the maxilla.

Effect of autologous growth factors in maxillary sinus augmentation: a systematic review

PURPOSE

The aim of the present study was to systematically evaluate the effect of autogenous platelet concentrates on the clinical and histomorphometric outcomes of maxillary sinus augmentation.

MATERIALS AND METHODS

MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched using a combination of specific search terms. Furthermore, a hand searching of the relevant journals and of the bibliographies of reviews was performed. Prospective comparative clinical studies were included. Implant survival and histomorphometric outcomes were evaluated.

RESULTS

Twelve studies were included. Four hundred forty-five sinus floor augmentation procedures were considered. No difference in implant survival was reported between test and control groups. Six studies reported a beneficial effect of platelet concentrates based on histomorphometric outcomes, while another six studies found no significant effect. A large heterogeneity was found regarding study design, surgical techniques, graft materials, clinical and histomorphometric outcome variables, and methods for preparing platelet concentrates. Favorable effects on soft tissue healing and postoperative discomfort reduction were often reported but not quantified.

CONCLUSIONS

A clear advantage of platelet concentrates could not be evidenced. Standardization in the experimental design is needed in order to detect the true effect of platelet concentrates in maxillary sinus augmentation procedure, especially regarding postoperative quality of life.

The effect of platelet-rich plasma (PRP) combined with a bone allograft on human periodontal ligament (PDL) cells

The prominent purpose of the study was the evaluation of the in vitro mitogenic effect of three different homologous platelet-rich plasma (PRP) preparations (PRPa, PRPb, PRPc) on three different lines of periodontal ligament (PDL) cells (PDL(1,2,3)), cultured alone or in combination with a demineralized freeze-dried allograft (DFBA). PDL cell cultures were derived from the mid root of three maxillary caries-free premolars extracted for orthodontic reasons. Cells were grown and reached confluence. To evaluate the mitogenic effect of all exogenous factors (PRPa, PRPb, PRPc and DFBA) on PDL cells, specific number of cells (10.000/well) was cultured in the presence or absence of the above factors. Each PRP preparation (5% v/v) was added in all cell lines, in the absence or presence of 10 mg/ml of DFBA. The cells were also treated with 25 ng/ml bFGF (positive control). The mitogenic effect was evaluated 24 h after incubation, using the Trypan blue exclusion assay. The results revealed that all PRP preparations act as potent mitogens as they significantly induced cell proliferation on PDL(1,2,3) lines. All PRP preparations when added alone in the PDL cell cultures, exhibited a significant advantage over the positive control (bFGF). The addition of DFBA to PRP did not influence significantly cell proliferation in all cell lines, comparatively to PRP alone, at the time -period studied. The findings of this study demonstrate the beneficial role of PRP alone or combined with the bone graft on periodontal ligament cells in vitro, suggesting that it may be considered as a potential biological approach in periodontal regeneration.

Effects of platelet-rich plasma on sinus bone graft: meta-analysis

BACKGROUND

This meta-analysis investigates the effects of platelet-rich plasma (PRP) on the sinus bone graft.

METHODS

PubMed, the Cochrane Library, and EMBASE were searched in January 2010.

RESULTS

Of 61 articles searched, eight controlled clinical trials, which included a total of 352 sinus bone graft cases in 191 patients, were included in the final analysis. In the fixed-effects meta-analysis, the implant survival was not significantly different between two groups in the patient-based data of four studies (relative risk [RR]: 1.02; 95% confidence interval [CI]: 0.97 to 1.08) and in the implant-based data of three studies (RR: 1.02; 95% CI: 0.99 to 1.04). The bone formation was significantly greater in the intervention group in the random-effects model (standardized mean difference [SMD]: 1.30; 95% CI: 0.21 to 2.39) in five studies with significant heterogeneity (I(2) = 76.2%). The bone-to-implant contact was not significantly different between two groups in the random-effects model (SMD: 1.02; 95% CI: -1.65 to 3.70) in two studies with significant heterogeneity (I(2) = 82.4%).

CONCLUSION

The present study indicates that there was sufficient evidence to support the use of PRP for bone formation on a sinus bone graft, whereas there was no significant effect on the implant survival and bone-to-implant contact.