Maxillary sinus augmentation with adult mesenchymal stem cells: a review of the current literature. Oral Surg Oral Med Oral Pathol Oral Radiol. 2013;115:717-723. [PMID: 23313230 DOI: 10.1016/j.oooo.2012.09.087]

Safety and Efficacy Results of BonoFill First-in-Human, Phase I/IIa Clinical Trial for the Maxillofacial Indication of Sinus Augmentation and Mandibular Bone Void Filling

PURPOSE

The gold standard for bone regeneration of bone deficiencies is still an autologous bone graft, which has considerable disadvantages; namely, the need for a second major surgery and the limited volume of bone available for harvesting. BonoFill (BF) is a novel, tissue-engineered, bone graft with intrinsic osteoinductive, osteoconductive, and osteogenic properties, consisting of the patient's own adipose tissue-derived mesenchymal stem cells, attached to hydroxyapatite particles. Here, we present the safety and efficacy results of BF first-in-human clinical study for maxillofacial bone tissue regeneration.

MATERIALS AND METHODS

Eleven eligible male and female subjects, aged 49-65 years, were enrolled into the clinical study in 2 clinical indications: Bone augmentation and bone void grafting in the jaws. Clinical follow-up was performed throughout a period of 6 months after BF treatment and included clinical examination, blood tests, CT scans, and biopsies collected from the transplantation site to assess chronic bone infection, changes in complete blood count, and adequate bone augmentation for implant placement.

RESULTS

The study results demonstrated that BF promoted adequate bone tissue regeneration without complications. Per our evaluation, there were no incidents of chronic bone infection, or significant changes in complete blood count, and the patients reported overall good health for the duration of the study. At trial end, in the sinus augmentation indication, the BF treated sites residual bone was augmented at an average of 6.36 mm (Δ new bone, n = 10) and the total bone height at the treated area was on average 11.44 mm (n = 10). In the indication of filling of bone voids, the patient's average residual bone height of 2.91 mm was 15.76 mm (n = 1) at trial end.

CONCLUSIONS

BF treatment was shown to be safe and resulted in newly generated bone, which provided adequate bone height for placement of dental implants. Thus, BF is a promising novel autologous bone graft for bone tissue repair.

Improved guided bone regeneration by combined application of unmodified, fresh autologous adipose derived regenerative cells and plasma rich in growth factors: A first-in-human case report and literature review

BACKGROUND

Novel strategies are needed for improving guided bone regeneration (GBR) in oral surgery prior to implant placement, particularly in maxillary sinus augmentation (GBR-MSA) and in lateral alveolar ridge augmentation (LRA). This study tested the hypothesis that the combination of freshly isolated, unmodified autologous adipose-derived regenerative cells (UA-ADRCs), fraction 2 of plasma rich in growth factors (PRGF-2) and an osteoinductive scaffold (OIS) (UA-ADRC/PRGF-2/OIS) is superior to the combination of PRGF-2 and the same OIS alone (PRGF-2/OIS) in GBR-MSA/LRA.

CASE SUMMARY

A 79-year-old patient was treated with a bilateral external sinus lift procedure as well as a bilateral lateral alveolar ridge augmentation. GBR-MSA/LRA was performed with UA-ADRC/PRGF-2/OIS on the right side, and with PRGF-2/OIS on the left side. Biopsies were collected at 6 wk and 34 wk after GBR-MSA/LRA. At the latter time point implants were placed. Radiographs (32 mo follow-up time) demonstrated excellent bone healing. No radiological or histological signs of inflammation were observed. Detailed histologic, histomorphometric, and immunohistochemical analysis of the biopsies evidenced that UA-ADRC/PRGF-2/OIS resulted in better and faster bone regeneration than PRGF-2/OIS.

CONCLUSION

GBR-MSA with UA-ADRCs, PRGF-2, and an OIS shows effectiveness without adverse effects.

Applications of Mesenchymal Stem Cells in Oral and Craniofacial Regeneration

The field of tissue engineering and regenerative medicine has been rapidly expanded through multidisciplinary integration of research and clinical practice in response to unmet clinical needs for reconstruction of dental, oral, and craniofacial structures. The significance of the various types of stem cells, specifically mesenchymal stem cells derived from the orofacial tissues, ranging from dental pulp stem cells to periodontal ligament stem cells to mucosa/gingiva has been thoroughly investigated and their applications in tissue regeneration are outlined in this article.

Morse Taper Connection Implants Placed in Grafted Sinuses in 65 Patients: A Retrospective Clinical Study with 10 Years of Follow-Up

PURPOSE

To investigate the 10-year survival and complication rates of Morse taper connection implants (MTCIs) placed in grafted sinuses.

METHODS

This study reports on patients treated with maxillary sinus augmentation (with the lateral window technique (LWT) or the transalveolar osteotomy technique (TOT)) and installed with MTCIs supporting fixed restorations (single crowns (SCs) and fixed partial dentures (FPDs)), in two dental clinics. The outcomes of the study were the 10-year implant survival and complication rates.

RESULTS

Sixty-five patients (30 males and 35 females) with a mean age of 62.7 (±10.2) years were installed with 142 MTCIs: 79 fixtures were inserted with the LWT and 63 were placed with the TOT. After ten years, five implants failed, for an overall survival rate of 96.5%. Three implants failed in the LWT group, for a survival rate of 96.3%; two implants failed in the TOT group, for a survival rate of 96.9%. The 10-year incidence of biologic complications was 11.9%. Prosthetic complications were all technical in nature and amounted to 7.6%.

CONCLUSIONS

MTCIs seem to represent a successful procedure for the prosthetic restoration of the grafted posterior maxilla, in the long term. This study was registered in the ISRCTN registry with number ISRCTN30772506.

Efficacy of a new coating of implant-abutment connections in reducing bacterial loading: an in vitro study

BACKGROUND

Titanium is the gold standard for dental implants, since it has demonstrated excellent biocompatibility and osseointegration properties. The rate of osseointegration is however affected by the surface morphology and peri-implant infections may affect fixture and the long-term osseointegration outcome. Thus chemical composition of a coating at the implant-abutment junction (IAJ) surface is expected to play a key role in preventing bacterial infection.

PURPOSE

In the present study a new antimicrobial polysiloxane coating functionalized with chlorexidine digluconate (PXT) has been tested in an in vitro model.

MATERIALS AND METHODS

Twenty implants were coated in the internal chamber with PXT and twenty were used as controls.

RESULTS AND CONCLUSIONS

Ten of the coated implants, preliminarily tested against Gram positive and negative bacteria and fungi, showed a complete inactivation of the microbial species after a 15 min contact. On the remaining ten treated implants a series of microbiological tests and PCR analysis, after contamination of the implant external medium, in which the implant have been immersed, with genetic modified Tannerella forsythia (TF) and Porphyromonas Gingivalis (PG), leads to the conclusion that the coating is capable of inactivating the microbial species penetrating the internal of the implant through the implant abutment junction.

Genetic susceptibility and periodontal disease: a retrospective study on a large italian sample

BACKGROUND

Periodontal disease (PD) is a multifactorial illness in which environment and host interact. The genetic component plays a key role in the onset of PD. In fact the genetic compound can modulate the inflammation of the mucous membranes and the loss of alveolar bone. The genetics of PD is not well understood. Previous studies suggest a strong association between PD occurrence and individual genetic profile. The role of genetic susceptibility could impact on the clinical manifestations of PD, and consequently on prevention and therapy.

MATERIALS AND METHODS

Genetic polymorphisms of VRD, IL6 and IL10 were investigated in Italian adults affected by PD. 571 cases classified according the criteria of the American Academy of Periodontology were included. All patients were Italian coming from three areas according to italian institute of statistics (ISTAT) (www.istat.it/it/archivio/regioni). The sample comprised 379 patients from North (66%), 152 from Central (26%) and 40 of South (8%).

RESULTS

No significant differences were found among allele distribution.

CONCLUSION

Chronic PD is a complex disease caused by a combination of genetic susceptibility, patients habits (oral hygiene, smoking, alcohol consumption) and oral pathogens. In our report no differences were detected among three Italian regions in allele distribution.

Prevalence of periodontal pathogens among italian patients with chronic periodontitis: a retrospective study on 2992 patients

PURPOSE

The aim of the present study was to evaluate the prevalence of some periodontal pathogens in Italian adults with chronic periodontitis.

MATERIALS AND METHODS

The sample consisted of 2992 patients with a clinical diagnosis of chronic periodontitis, based on the criteria of the American Academy of Periodontology, sampled in the period 2013-2016: 2108 patients were from Northern, 690 from Central and 194 from Southern Italy. Porphyromonas gengivalis, Treponema denticola, and Tannerella forsythia were investigated in all patients of the present study, while Campylobacter rectus, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans only in 2514 (84%) patients. Subgingival plaque samples of the four sites of greatest probing depth in each patient were used to obtain subgingival microbiota and then processed by quantitative polymerase chain reaction.

RESULTS

Periodontal pathogens had the following presence respect to all amount of patients: Aggregatibacter actinomycetemcomitans 16.1%, Campylobacter rectus 73.4%, Fusobacterium nucleatum 93.8%, Porphyromonas gengivalis 65.5%, Treponema denticola 66.4%, and Tannerella forsythia 72.7%. There are no significant statistical differences among geographic areas both for the total bacterial and the single species except for T. Denticola and C. Rectus, which prevalence was significantly higher in Southern Italy (P value <.05). The other investigated species were equally distributed among different regions. A. actinomycetemcomitans was the rarer species detected in this study, while F. nucleatum was the commonest. No differences among areas where observed as regard of the mean bacterial load except for F. Nucleatum whose prevalence in Northern Italy was lower then both in Central and Southern Italy (P value <.05).

CONCLUSIONS

The results of our study didn't show different geographic distribution of periodontal pathogens among Italian population of the three areas investigated. The homogeneity of the results could be related to genetic and environmental factors.

Applications of biomaterials for bone augmentation of jaws: clinical outcomes and in vitro studies

Partially or totally edentulous jaws frequently undergoes from moderate to severe bone atrophy with problems of prosthetic rehabilitation. The inability to make a prosthetic rehabilitation on implants may led to the use of a partial or total removable denture with difficulties in eating and speech, ulcerations of the oral mucosa and loss of facial vertical dimension. These problems may be solved performing bone augmentation procedures. Bone grafts and distraction osteogenesis brought implant dentistry from an experimental practice to become a consolidate dental procedure. Bone grafts, in particular, are currently a valuable treatment modality for the prosthetic rehabilitation. Numerous biomaterials have been developed for the rehabilitation of partially or totally edentulous jaws with fixed or removable dentures. The aim of this paper is to describe biomaterials for bone augmentation. Biomaterials are gradually resorbed by the osteoclasts and replaced by new bone formed through osteoblastic activity. Many biomaterials have been studied, but the most common are as follows: Allogro®, Algipore®, Osteobiol®, Peptide-15, Engipore®, Medpore®, Osteoplant®, Calcium sulfate, Perioglass®, Bio-Oss®, Calcium phosphate.

Mesenchymal stem cells in maxillary sinus augmentation: A systematic review with meta-analysis

AIM: To investigate the effectiveness of mesenchymal stem cells (MSCs) in maxillary sinus augmentation (MSA), with various scaffold materials.

METHODS: MEDLINE, EMBASE and SCOPUS were searched using keywords such as sinus graft, MSA, maxillary sinus lift, sinus floor elevation, MSC and cell-based, in different combinations. The searches included full text articles written in English, published over a 10-year period (2004-2014). Inclusion criteria were clinical/radiographic and histologic/ histomorphometric studies in humans and animals, on the use of MSCs in MSA. Meta-analysis was performed only for experimental studies (randomized controlled trials and controlled trials) involving MSA, with an outcome measurement of histologic evaluation with histomorphometric analysis reported. Mean and standard deviation values of newly formed bone from each study were used, and weighted mean values were assessed to account for the difference in the number of subjects among the different studies. To compare the results between the test and the control groups, the differences of regenerated bone in mean and 95% confidence intervals were calculated.

RESULTS: Thirty-nine studies (18 animal studies and 21 human studies) published over a 10-year period (between 2004 and 2014) were considered to be eligible for inclusion in the present literature review. These studies demonstrated considerable variation with respect to study type, study design, follow-up, and results. Meta-analysis was performed on 9 studies (7 animal studies and 2 human studies). The weighted mean difference estimate from a random-effect model was 9.5% (95%CI: 3.6%-15.4%), suggesting a positive effect of stem cells on bone regeneration. Heterogeneity was measured by the I² index. The formal test confirmed the presence of substantial heterogeneity (I² = 83%, P < 0.0001). In attempt to explain the substantial heterogeneity observed, we considered a meta-regression model with publication year, support type (animal vs humans) and follow-up length (8 or 12 wk) as covariates. After adding publication year, support type and follow-up length to the meta-regression model, heterogeneity was no longer significant (I² = 33%, P = 0.25).

CONCLUSION: Several studies have demonstrated the potential for cell-based approaches in MSA; further clinical trials are needed to confirm these results.

Clinical applications of cell-based approaches in alveolar bone augmentation: a systematic review

BACKGROUND

Cell-based approaches, utilizing adult mesenchymal stem cells (MSCs), are reported to overcome the limitations of conventional bone augmentation procedures.

PURPOSE

The study aims to systematically review the available evidence on the characteristics and clinical effectiveness of cell-based ridge augmentation, socket preservation, and sinus-floor augmentation, compared to current evidence-based methods in human adult patients.

MATERIALS AND METHODS

MEDLINE, EMBASE, and CENTRAL databases were searched for related literature. Both observational and experimental studies reporting outcomes of "tissue engineered" or "cell-based" augmentation in ≥5 adult patients alone, or in comparison with non-cell-based (conventional) augmentation methods, were eligible for inclusion. Primary outcome was histomorphometric analysis of new bone formation. Effectiveness of cell-based augmentation was evaluated based on outcomes of controlled studies.

RESULTS

Twenty-seven eligible studies were identified. Of these, 15 included a control group (8 randomized controlled trials [RCTs]), and were judged to be at a moderate-to-high risk of bias. Most studies reported the combined use of cultured autologous MSCs with an osteoconductive bone substitute (BS) scaffold. Iliac bone marrow and mandibular periosteum were frequently reported sources of MSCs. In vitro culture of MSCs took between 12 days and 1.5 months. A range of autogenous, allogeneic, xenogeneic, and alloplastic scaffolds was identified. Bovine bone mineral scaffold was frequently reported with favorable outcomes, while polylactic-polyglycolic acid copolymer (PLGA) scaffold resulted in graft failure in three studies. The combination of MSCs and BS resulted in outcomes similar to autogenous bone (AB) and BS. Three RCTs and one controlled trial reported significantly greater bone formation in cell-based than conventionally grafted sites after 3 to 8 months.

CONCLUSIONS

Based on limited controlled evidence at a moderate-to-high risk of bias, cell-based approaches are comparable, if not superior, to current evidence-based bone grafting methods, with a significant advantage of avoiding AB harvesting. Future clinical trials should additionally evaluate patient-based outcomes and the time-/cost-effectiveness of these approaches.