Reliability of Cone Beam Computed Tomography in Determining Mineralized Tissue in Augmented Sinuses

PURPOSE

The aim of this study was to analyze cone beam computed tomography (CBCT) densitometries of maxillary sinuses augmented with human bone allograft. In addition, previously obtained microradiographic specimens were used to verify the diagnostic potential of CBCT.

MATERIALS AND METHODS

A two-stage protocol was conducted in 21 consecutive patients, all with a crestal bone height < 2 mm. Mineralized human bone allograft particles were used to augment sinuses using a lateral window approach. A succession of CBCT scans of the maxilla were taken before surgery, immediately after sinus augmentation, and 6, 10, and 18 months after implant placement. Using virtual probes, CBCT images taken at 6, 8, and 10 mm from the crestal surface were processed with medical imaging software and expressed as gray level (GL).

RESULTS

A total of 24 sinus augmentation procedures were performed in 21 patients. The average values of CBCT-GL ranged from 571 to 654, presenting the maximum value at 8 mm immediately after implant placement and the minimum value at 6 mm after 10 months. Furthermore, it was found that the graft mineral content decreased over time, completely disappearing between 10 and 11 months.

CONCLUSION

CBCT and the medical imaging software employed for imaging visualization are reliable tools to study biomaterial behavior after sinus augmentation procedures. In addition, results from this study demonstrate that a complete resorption of human bone allograft is possible. Due to the limited sample size, further clinical and morphometric studies are needed.

The maintenance of inserted titanium implants: in-vitro evaluation of exposed surfaces cleaned with three different instruments

OBJECTIVE

Changes to titanium implants smooth-surfaces after instrumentation were comparatively analyzed using low-vacuum scanning electron microscopy (LV-SEM) and white-light confocal (WLC) profilometry, to accurately evaluate curved surfaces.

MATERIAL AND METHODS

Sixty titanium implants screwed to their abutments were randomly split into three groups for cleaning treatment with (S) stainless-steel Gracey-curettes, (T) titanium Langer-curettes, and (P) an ultrasonic-device with the probe covered with a plastic-tip. One sector of each implant was left unprocessed (U). The other sectors were cleaned for either 60 s, to simulate a single cleaning session, or 180 s to simulate a series of sessions. Surface morphology was analyzed by LV-SEM, without metal sputtering. Quantitative evaluations of the roughness of surfaces were performed using a WLC-profilometer. The Wilcoxon and the Mann-Whitney tests were used in statistical comparisons.

RESULTS

U-surfaces showed that thin transverse ridges and grooves, i.e. a polarized surface roughness was substantially compromised after S-instrumentation. Small surface alterations, increasing with time, were also recorded after T-·and·P-instrumentation, although to a lesser degree. The gap of the fixture-abutment connection appeared almost completely clean after T-, clotted with titanium debris after S-, and clotted with plastic debris after P-treatment. The mean roughness (Ra) was unchanged after P-, significantly increased after S- and decreased after T-treatment, when compared with U. The Rz roughness-parameter, calculated along the fixture Y-axis, of S, T, and P resulted similar and significantly lower than that of U. Rz (X-axis) resulted unchanged after P-, slightly increased (+40%) after T-, and greatly increased (+260%) after S-treatment, this latter being statistically significant when compared with U.

CONCLUSIONS

The careful use of titanium-curettes could produce only minimal smooth surface alteration particularly over prolonged treatments, and avoid debris production that could endanger implant preservation.

Analysis of protein expression in periodontal pocket tissue: a preliminary study

Background

The periodontal disease is caused by a set of inflammatory disorders characterized by periodontal pocket formation that lead to tooth loss if untreated. The proteomic profile and related molecular conditions of pocket tissue in periodontally-affected patients are not reported in literature. To characterize the proteomic profile of periodontally-affected patients, their interproximal periodontal pocket tissue was compared with that of periodontally-healthy patients. Pocket-associated and healthy tissue samples, harvested during surgical therapy, were treated to extract the protein content. Tissues were always collected at sites where no periodontal-pathogenic bacteria were detectable. Proteins were separated using two-dimensional gel electrophoresis and identified by liquid chromatography/mass spectrometry. After identification, four proteins were selected for subsequent Western Blot quantitation both in pathological and healty tissues.

Results

A significant unbalance in protein expression between healthy and pathological sites was recorded. Thirty-two protein spots were overall identified, and four proteins (S100A9, HSPB1, LEG7 and 14-3-3) were selected for Western blot analysis of both periodontally-affected and healthy patients. The four selected proteins resulted over-expressed in periodontal pocket tissue when compared with the corresponding tissue of periodontally-healthy patients. The results of Western blot analysis are congruent with the defensive and the regenerative reaction of injured periodontal tissues.

Conclusions

The proteomic analysis was performed for the first time directly on periodontal pocket tissue. The proteomic network highlighted in this study enhances the understanding of periodontal disease pathogenesis necessary for specific therapeutic strategies setting.

Effects of soft-drinks and remineralising treatment on teeth assessed by morphological and quantitative X-ray investigations

AIM

To morphologically and chemical-physically analyse both the surface and the subsurface of enamel undergoing soft- drink demineralisation and remineralisation treatment.

MATERIALS AND METHODS

Fifteen human premolars were split and immersed in saline or three popular soft drinks, as demineralising agent, 15 minutes per day, for seven days at room temperature. Half of drink-processed teeth was then treated with casein phosphopeptide-amorphous calcium phosphate, as remineralising agent, for an additional seven days. The surface morphology was evaluated by stereomicroscope and scanning electron microscope (SEM). Teeth were then re-embedded and sectioned, and analysed under SEM and X-ray microprobe.

RESULTS

Drink-processed teeth showed root pigmentation, opacification and deterioration of the superficial enamel. The enamel surface resulted greatly furrowed after drink processing, and apparently restored after remineralising treatment. However, in tooth sections, SEM showed always a subsurface demineralisation of dentine and enamel, in particular at the cementoenamel junction, also after reminalising treatment. The remineralising agent produced a partial remineralisation of the subsurface enamel, sometimes statistically significant, but not in hydroxyapatite stoichiometry.

CONCLUSION

Soft-drink erosion impaired not only the surface but also the subsurface enamel. The applied remineralising treatment, yielding some effects on surface and subsurface enamel reversing basically the decalcification process.

Piezosurgical treatment of crestal bone: quantitative comparison of post-extractive socket outcomes with those of traditional treatment

OBJECTIVE

The study aimed to quantitatively compare, for the first time, the clinical outcomes of crestal bone volume resorption in sockets undergoing traditional extraction technique (TET) or piezosurgical extraction technique (PET), also considering the influence of buccal plate thickness.

MATERIAL AND METHODS

In this prospective study, 19 sockets were randomly treated with TET, and 18 sockets were randomly treated with PET. Furthermore, patients were split into subgroup A, with buccal bone plate thickness (BPT) ≤1 mm, and subgroup B, with BPT>1 mm. Buccal (BCH) and palatal (PCH) cortex height, bucco-palatal ridge (BPR) width were monitored at tooth extraction and after the 4-month post-extractive period of natural healing.

RESULTS

After 4 months, BCH, PCH and BPR width decreased more in the TET than in the PET group, but only the BPR decrease was statistically significant (P = 0.034) after ANOVA test. In both TET and PET groups, all B subgroup patients showed a lower decrease than A subgroup patients for both BCH, PCH and BPR, statistically significant for PCH (P = 0.019) and BPR (P < 0.001) of TET group, and BPR (P = 0.002) of PET group, after ANOVA. Both A and B subgroups of PET showed a statistically significant lower decrease than the corresponding subgroups of TET, comparing A (P = 0.005) and B (P = 0.037) subgroups for BPR, after ANOVA.

CONCLUSIONS

With both thin and thick buccal plates, the piezosurgical extraction technique of teeth significantly decreases the horizontal resorption of the hard tissue ridge, but not the vertical resorption. Moreover, buccal plate thickness seems to be a key factor in post-extractive bone resorption: the thinner the buccal plate the greater the horizontal crestal bone loss.

Melanocortins protect against brain damage and counteract cognitive decline in a transgenic mouse model of moderate Alzheimer׳s disease

We previously reported that melanocortins induce neuroprotection in experimental acute and chronic neurodegenerative conditions, including Alzheimer׳s disease (AD) of mild severity. Here we investigated whether melanocortins afford neuroprotection and counteract cognitive decline in AD with a medium level of severity by using 24 week-old (at the start of the study) APPSwe transgenic mice (Tg2576). Saline-treated (days 1-50) control Tg2576 mice showed an impairment in spatial learning and memory, associated (at day 50, end of the study) with hippocampus at low levels of the synaptic activity-dependent gene Zif268, relevant brain changes such as cerebral cortex/hippocampus increased level of β-amyloid (Aβ) deposit, and neuronal loss, in comparison with wild-type animals. Treatment of Tg2576 mice (once daily at days 1-50) with a nanomolar dose of the melanocortin analog [Nle4,D-Phe7]α-melanocyte-stimulating hormone (NDP-α-MSH) reduced cerebral cortex/hippocampus level of Aβ deposit, decreased neuronal loss, increased hippocampus Zif268 expression and improved cognitive functions, relative to saline-treated Tg2576 mice. Pharmacological blockade of melanocortin MC4 receptors with the MC4 receptor antagonist HS024 prevented all favorable effects of NDP-α-MSH. Our data indicate that MC4 receptor-stimulating melanocortins are able to counteract cognitive decline in experimental AD of medium severity through induction of neuroprotection and improvement of synaptic transmission. After further studies, these agents could gain a role as disease modifying therapeutics for AD.

Melanocortins protect against progression of Alzheimer's disease in triple-transgenic mice by targeting multiple pathophysiological pathways

Besides specific triggering causes, Alzheimer's disease (AD) involves pathophysiological pathways that are common to acute and chronic neurodegenerative disorders. Melanocortins induce neuroprotection in experimental acute neurodegenerative conditions, and low melanocortin levels have been found in occasional studies performed in AD-type dementia patients. Here we investigated the possible neuroprotective role of melanocortins in a chronic neurodegenerative disorder, AD, by using 12-week-old (at the start of the study) triple-transgenic (3xTg-AD) mice harboring human transgenes APPSwe, PS1M146V, and tauP301L. Treatment of 3xTg-AD mice, once daily until the end of the study (30 weeks of age), with the melanocortin analog [Nle(4),D-Phe(7)]-α-melanocyte-stimulating hormone (NDP-α-MSH) reduced cerebral cortex/hippocampus phosphorylation/level of all AD-related biomarkers investigated (mediators of amyloid/tau cascade, oxidative/nitrosative stress, inflammation, apoptosis), decreased neuronal loss, induced over-expression of the synaptic activity-dependent gene Zif268, and improved cognitive functions, relative to saline-treated 3xTg-AD mice. Pharmacological blockade of melanocortin MC4 receptors prevented all neuroprotective effects of NDP-α-MSH. Our study identifies, for the first time, a class of drugs, MC4 receptor-stimulating melanocortins, that are able to counteract the progression of experimental AD by targeting pathophysiological mechanisms up- and down-stream of β-amyloid and tau. These data could have important clinical implications.

Risk factors and socioeconomic condition effects on periodontal and dental health: A pilot study among adults over fifty years of age

OBJECTIVE

Observational studies on the association among systemic/general and oral cavity indices, tooth loss, periodontal conditions, and socioeconomic inequalities are to be still performed in the population of Southern Europe. This study aims to determine the extent of this relationship among Italian healthy adults 50 years of age and above.

MATERIALS AND METHODS

Socioeconomic and lifestyle characteristics, cardiovascular indicators, and systemic indices were examined by contrasting the dental indices among adult people of Northern Italy. Data were processed through correlation analysis, and multivariate analysis was carried out using seemingly unrelated regressions.

RESULTS

A total of 118 adults 50 years of age and above, after anamnesis, underwent systemic and dental examination. Their socioeconomic status was found to be inversely associated only with smoking and dental parameters. Unexpected outcomes between lifestyle and risk factors were detected. The statistical analysis showed an uneven correlation among dental indices and between those indices and the socioeconomic status, such as, a periodontal condition, apparently free from influences, unusually became worse as the socioeconomic status enhanced.

CONCLUSIONS

The study outcomes indicate a relationship between tooth loss and conservative endodontic therapy, but they result in alternative choices. Nevertheless, the socioeconomic status has an inverse relationship with tooth loss and conservative endodontic therapy, but a direct relation with worsening of the periodontal condition. This pilot study highlights a need for the public health administration to adopt a socioeconomic assessment not only based on the household income, but also to accordingly improve its therapeutic course.

Microradiography and microcomputed tomography comparative analysis in human bone cores harvested after maxillary sinus augmentation: a pilot study

OBJECTIVES

The aim of this study was to compare microradiography (MR) and microcomputed tomography (μCT) analysis of bone samples following maxillary sinus augmentation at different time periods and determine the relationships between measured area and volume fractions.

MATERIALS AND METHODS

Lateral window sinus grafts were performed on 10 patients using a mineralized human bone allograft (MHBA). At implant placement, 5-13 months after surgery, 10 bone core biopsies were harvested. Prior to histologic sectioning, bone samples were evaluated with μCT. The morphometric parameters computed by MR and μCT were compared using Pearson's correlation and Bland and Altman analysis and included hard tissue fraction (HV/TV:%), soft tissue fraction (SV/TV:%), vital bone fraction (BV/TV:%) and residual graft fraction (GV/TV:%).

RESULTS

Strong positive correlation between MR and μCT was found for HV/TV and SV/TV and BV/TV [r = 0.84, 0.84 and 0.69, respectively] but weak for GV/TV [r = 0.10].

CONCLUSION

μCT technology shows promising potential as an indicator of bone morphology changes; however, caution should be used in interpreting morphometric parameters, as the different methods reveal important biases.

Up-regulation of the canonical Wnt-3A and Sonic hedgehog signaling underlies melanocortin-induced neurogenesis after cerebral ischemia

In experimental cerebral ischemia, melanocortin MC4 receptor agonists induce neuroprotection and neurogenesis with subsequent long-lasting functional recovery. Here we investigated the molecular mechanisms underlying melanocortin-induced neurogenesis. Gerbils were subjected to transient global cerebral ischemia, then they were treated every 12 h, and until sacrifice, with 5-bromo-2'-deoxyuridine (BrdU; to label proliferating cells), and the melanocortin analog [Nle(4),d-Phe(7)]α-melanocyte-stimulating hormone (NDP-α-MSH) or saline. NDP-α-MSH increased hippocampus dentate gyrus (DG) expression of Wnt-3A, β-catenin, Sonic hedgehog (Shh), Zif268, interleukin-10 (IL-10) and doublecortin (DCX), as detected at days 3, 6 and 10 after the ischemic insult. Further, an elevated number of BrdU immunoreactive cells was found at days 3 and 10, and an improved histological picture with reduced neuronal loss at day 10, associated with learning and memory recovery. Pharmacological blockade of the Wnt-3A/β-catenin and Shh pathways, as well as of melanocortin MC4 receptors, prevented all effects of NDP-α-MSH. These data indicate that, in experimental brain ischemia, treatment with melanocortins acting at MC4 receptors induces neural stem/progenitor cell proliferation in the DG by promptly and effectively triggering the canonical Wnt-3A/β-catenin and Shh signaling pathways. Activation of these pathways is associated with up-regulation of the repair factor Zif268 and the neurogenesis facilitating factor IL-10, and it seems to address mainly toward a neuronal fate, as indicated by the increase in DCX positive cells.

Non-bacterial protein expression in periodontal pockets by proteome analysis

OBJECTIVES

To compare the proteomic profile of inter-proximal pocket tissues with inter-proximal healthy tissues in the same subject to reveal proteins associated with periodontal disease in sites where periodontopathogenic bacteria were not detectable.

METHODS

Twenty-five healthy patients, with moderate-to-advanced chronic periodontitis and presenting with at least one intra-bony defect next to a healthy inter-proximal site were enrolled. The periodontal defects were treated with osseous resective surgery, and the flap design included both the periodontal pockets and the neighbouring inter-proximal healthy sites. Pocket-associated and healthy tissues were harvested for proteomic analyses.

RESULTS

Fifteen proteins were differently expressed between pathological and healthy tissues. In particular, annexin A2, actin cytoplasmic 1, carbonic anhydrase 1 & 2; Ig kappa chain C region (two spots) and flavinreductase were overexpressed, whereas 14-3-3 protein sigma and zeta/delta, heat-shock protein beta -1 (two spots), triosephosphateisomerase, peroxiredoxin-1, fatty acid-binding protein-epidermal, and galectin-7 were underexpressed in pathological tissue.

CONCLUSIONS

The unbalanced functional network of proteins involved could hinder adequate tissue response to pathogenic noxa. The study of periodontal pocket tissue proteomic profile would be crucial to better understand the pathogenesis of and the therapeutic strategies for periodontitis.

Is socket healing conditioned by buccal plate thickness? A clinical and histologic study 4 months after mineralized human bone allografting

OBJECTIVE

The aim of this study was to clinically and histologically analyze the healing of grafted sockets by mineralized human bone allograft (MHBA) and nongrafted sockets, correlating the results with buccal plate thickness.

MATERIAL AND METHODS

Thirty-one sockets were randomly split into control (CG) and treatment (MHBA grafted) (TG) groups and, subsequently, into four subgroups according to buccal plate thickness: a ≤ 1 mm and b > 1 mm. Ridge thickness, depth, and height were monitored. Four months after, at implant placement, a bone core biopsy for histologic and morphometric analyses was taken.

RESULTS

The differences of buccal height (TG-a -0.27 and CG-a -1.17 mm) and width (TG-a 0.55 and CG-a 2.67 mm, TG-b 0.12 and CG-b 1.17 mm) were statistically significant. The increase in bone amount CG-b (28.17%) compared with CG-a (16.98%) was statistically significant. Soft tissue amount of TG-b (54.21%) and TG-a (56.91%) was lower than that of CG-b (71.83%) and CG-a (83.01%), both being statistically significant (P = 0.002).

CONCLUSIONS

The results proved that thin buccal plates had a worse outcome on socket healing and that network formation by MBHA not only predisposes a successful implant insertion but also acts as size keeper.

Quantitative comparison of cone beam computed tomography and microradiography in the evaluation of bone density after maxillary sinus augmentation: a preliminary study

PURPOSE

Cone beam computed tomography (CBCT) and microradiographic analyses were comparatively performed in maxillary sinus augmentation to preliminarily verify the diagnostic potential of CBCT on the evaluation of bone regeneration.

MATERIALS AND METHODS

A two-stage protocol was conducted in 19 consenting patients, all having the crestal bone ≤2 mm, in private dental office. Mineralized human bone allograft particles were used to augment sinus using lateral window approach. A succession of CBCT scans of the maxilla was taken before surgery, after sinus augmentation, and immediately after implant insertion. Using virtual probes, CBCT data were processed by medical imaging software and expressed as gray level (GL). A bone core biopsy was taken at implant placement, 6 months after surgery. Microradiography of transverse sections, taken 6, 8, and 10 mm from the crestal surface, of methacrylate-embedded biopsies was performed to analyze and to evaluate the mineralized material amount (MM%).

RESULTS

A total of 21 sinus augmentations were performed. CBCT (mean GL: 646-693) data were not statistically different when comparing 6-, 8-, and 10-mm sites to after grafting/implant-insertion values. Furthermore, microradiographic (mean MM%: 45.3-48.3) data were not statistically different comparing 6-, 8-, and 10-mm sites, due to variation of values among patients. A GL and MM% parallelism was identified considering each patient, instead. A significant correlation (p < .001) between GL and MM% was found after both Wilcoxon test for paired data and simple linear regression analysis.

CONCLUSIONS

The preliminary result clearly demonstrated the predictability of the CBCT analysis. Due to the limited sample and great variations of the MM% recorded in patients, further clinical and morphometric studies are needed to fulfill diagnostic expectations.

In vivo comparison of two bone substitutes in the distal femur of the rabbit

PURPOSE

This study aimed to microradiographically evaluate the healing of grafted defects using a surgically standardized model that was suitable for comparing the regenerative potential of different grafts.

MATERIALS AND METHODS

Two different biomaterials, bovine porous bone mineral (BPBM) and nanohydroxyapatite (NHA), were used to fill defects produced in the distal epiphyses of 10 adult male rabbits for 2 and 4 months. Three rabbits were left untreated, without defects, as controls. Evaluations were performed on microradiographs of sections of polymethyl methacrylate-embedded rabbit epiphyses. The amounts of graft material and bone were evaluated by splitting the filled hole into three portions.

RESULTS

A greater amount of BPBM granules were in contact with bone at both 2 and 4 months versus the NHA (statistically significant difference in the central portion of the defect), and a persistence of the BPBM over time was apparent. The amount of NHA decreased from the inner to the outer portion of the defect, particularly after 4 months. The bone amount increased from the inner to the outer portion, particularly for the NHA graft, which produced an early cortex. The amount of mineralized material reached about 80% in the BPBM and 40% to 60% in the NHA after 4 months.

CONCLUSION

Both the analyzed biomaterials performed adequately for bone regeneration. The two biomaterials are probably suitable for grafting defects related to early cortical formation or spacemaintaining clinical requirements.

Treatment of cerebral ischemia with melanocortins acting at MC4 receptors induces marked neurogenesis and long-lasting functional recovery

Melanocortins produce neuroprotection against ischemic stroke with subsequent long-lasting functional recovery, through melanocortin MC(4) receptor activation. Here we investigated whether the long-lasting beneficial effect of melanocortins in stroke conditions is associated with a stimulation of neurogenesis. Gerbils were subjected to transient global cerebral ischemia by occluding both common carotid arteries for 10 min; then, they were prepared for 5-bromo-2'-deoxyuridine (BrdU) labeling of proliferating cells. Delayed treatment (up to 9 h after the ischemic injury) for 11 days with the melanocortin analog [Nle(4),D-Phe(7)]α-melanocyte-stimulating hormone (NDP-α-MSH) improved learning and memory throughout the 50-day observation period. Immunohistochemical examination of the hippocampus on day 50 showed, in the dentate gyrus, an elevated number of BrdU immunoreactive cells colocalized with NeuN (used as indicator of mature neurons) and Zif268 (used as indicator of functionally integrated neurons). Retrospective analysis during the early stage of neural stem/progenitor cell development (days 3 and 4 after stroke) showed, in NDP-α-MSH-treated gerbils, a high degree of daily cell proliferation and revealed that NDP-α-MSH favorably affects Wnt-3A signaling pathways and doublecortin expression. Pharmacologic blockade of MC(4) receptors prevented all effects of NDP-α-MSH. These data indicate that treatment of cerebral ischemia with MC(4) receptor agonists induces, with a broad window of therapeutic opportunity, long-lasting functional recovery associated with a large number of mature and likely functional newborn neurons in brain injured areas. Our findings reveal previously undescribed effects of melanocortins which might have major clinical implications.

Melanocortin MC₄ receptor agonists counteract late inflammatory and apoptotic responses and improve neuronal functionality after cerebral ischemia

Indirect evidence indicates that, in cerebral ischemia, melanocortins have neuroprotective effects likely mediated by MC₄ receptors. To gain direct insight into the role of melanocortin MC₄ receptors in ischemic stroke, we investigated the effects of a highly selective MC₄ receptor agonist. Gerbils were subjected to transient global cerebral ischemia by occluding both common carotid arteries for 10 min. In saline-treated stroke animals, an impairment in learning and memory occurred that, at day 11 after stroke, was associated with hippocampus up-regulation of tumor necrosis factor-α (TNF-α), BAX, activated extracellular signal-regulated kinases (ERK1/2), c-jun N-terminal kinases (JNK1/2) and caspase-3, down-regulation of Bcl-2, and neuronal loss. Treatment for 11days with the selective melanocortin MC₄ receptor agonist RO27-3225, as well as with the well known non-selective [Nle⁴,D-Phe⁷]α-melanocyte-stimulating hormone (NDP-α-MSH) as a reference non-selective melanocortin, counteracted the inflammatory and apoptotic responses, as indicated by the changes in TNF-α, BAX, ERK1/2, JNK1/2, caspase-3 and Bcl-2 protein expression. Furthermore, melanocortin treatment reduced neuronal loss and dose-dependently improved learning and memory. These positive effects were associated with overexpression of Zif268, an immediate early gene involved in injury repair, synaptic plasticity and memory formation. Pharmacological blockade of MC₄ receptors with the selective MC₄ receptor antagonist HS024 prevented all effects of RO27-3225 and NDP-α-MSH. These data give direct evidence that stimulation of MC₄ receptors affords neuroprotection and promotes functional recovery from stroke, by counteracting prolonged and/or recurrent inflammatory and apoptotic responses, and likely by triggering brain repair pathways.

Bone-defects healing by high-molecular hyaluronic acid: preliminary results

AIM.: The aim of this study is to evaluate the capability of Hyaloss™ matrix (Fab - Fidia Advanced Biopolymers - Pd - Italy), a biomaterial based on hyaluronic acid, used as organic scaffold in bone repair in post-extractive defects.

MATERIALS AND METHODS

20 post-extractive sockets were selected, with similar size defects in the same patient and in the same hemiarch. Hyaluronic acid with high molecular weight (Hyaloss™ matrix, Fab - Pd - Italy) was mixed with autologous bone obtained using Safescraper(®) curve (Meta - Re - Italy) to repair post-extractive sites. Safescraper(®) is a cutting edge system that allows to the collection of autologous bone without using traditional, incision-based collection techniques, which could cause discomfort to the patient.

RESULTS

Clinical and hystological evaluations were performed, four months after grafting, in the maxilla and in the mandible. From a clinical point of view Hyaloss™ matrix mixed with autologous bone and patient's blood becomes a substance similar to gel, which is easy to insert in to the defect. From a hystological point of view, in the treated site there is the presence of an erosive activity, with accelerated angiogenetic and bone remodelling activities.

CONCLUSIONS

The preliminary results show an acceleration of the bone deposit process and of its remodelling due to the presence of Hyaloss™ matrix, which, from a clinical point of view, improves the handling and application of the bone matrix inside the defects and, from a hystologic point of view makes it possible to obtain bone regeneration in less time when it is used with autologous bone.