Implant-Supported PMMA Monolithic Full-Arch Rehabilitation with Surgical Computer-Planned Guide and Immediate Provisional: A Case Report with One Year Follow-Up.

The aim of this case report is to describe the surgical and prosthetic procedures to achieve maxillary and mandibular implant-supported PMMA monolithic full-arch rehabilitation (PMFR) with surgical computer-planned guide and immediate provisional. In such cases, the correct planning of dental implants' position, length, and diameter and the prosthetic phases via computer-aided design are very important to achieve good aesthetic and functional long-lasting results.

Biologic and clinical aspects of integration of different bone substitutes in oral surgery: a literature review.

Many bone substitutes have been proposed for bone regeneration, and researchers have focused on the interactions occurring between grafts and host tissue, as the biologic response of host tissue is related to the origin of the biomaterial. Bone substitutes used in oral and maxillofacial surgery could be categorized according to their biologic origin and source as autologous bone graft when obtained from the same individual receiving the graft; homologous bone graft, or allograft, when harvested from an individual other than the one receiving the graft; animal-derived heterologous bone graft, or xenograft, when derived from a species other than human; and alloplastic graft, made of bone substitute of synthetic origin. The aim of this review is to describe the most commonly used bone substitutes, according to their origin, and to focus on the biologic events that ultimately lead to the integration of a biomaterial with the host tissue.

Invasive Cervical Resorption: A Case Series with 3-Year Follow-Up.

Invasive cervical resorption (ICR) lesion is an aggressive form of tooth destruction that usually begins immediately below the epithelial attachment. It has been described as a purely inflammatory reaction that can be started by microorganism infection, or an aseptic resorptive process that can be secondarily infected. The potential etiologic and predisposing factors for ICR are orthodontic treatment, traumatic injuries, bleaching, periodontal therapy, and idiopathic factors. This case series with a 3-year follow-up shows that Class 2 ICR lesions have a good prognosis in 100% of cases. Class 3 ICR lesions should be considered at risk. However, in the authors' experience, the treatment of Class 3 ICR lesions is compatible with tooth maintenance.

Aesthetic Surgical Crown Lengthening Procedure.

The aim of this case report was to describe the surgical sequence of crown lengthening to apically reposition the dentogingival complex, in addition to an esthetic restorative procedure. Many different causes can be responsible for short clinical crown. In these cases, the correct execution of a restorative or prosthetic rehabilitation requires an increasing of the crown length. According to the 2003 American Academy of Periodontology (Practice Profile Survey), crown lengthening is the most habitual surgical periodontal treatment.

Morphological Aspect and iNOS and Bax Expression Modification in Bone Tissue Around Dental Implants Positioned Using Piezoelectric Bone Surgery Versus Conventional Drill Technique.

BACKGROUND: The aim of this work is to evaluate differences occurring in bone tissue around dental implants positioned using piezoelectric or conventional drill technique. METHODS: Twenty-four implants were inserted bilaterally in the iliac crest of 6 sheep after site preparation through a piezoelectric instrument (Test) or after site preparation through conventional drill technique with rotary instruments (Control). Animals were randomly divided to be euthanized at 15 and 30 days post-intervention (p.i.); peri-implant bone samples were withdrawn and processed for histological analysis and immunohistochemical evaluation of iNOS and Bax expression. RESULTS: Active remodeling phenomena in both Test and Control samples are showed at 15 days p.i., while at 30 days p.i., the overall organization of the peri-implant bone resembles native bone tissue. Immunohistochemical evaluation reveals a statistically significant increase of both iNOS and Bax expression at 15 days p.i. compared to samples obtained 30 days p.i. and to native bone. At both healing times, a higher but not statistically significant iNOS and Bax expression is recorded in samples from Control compared to Test Group. CONCLUSION: Even if the insertion protocol does not seem to significantly interfere with the long-term healing process, implant site preparation through the piezoelectric bone surgery technique may allow a reduction of peri-implant bone tissue inflammation and support a more rapid bone tissue healing phase.

In Vitro Behavior of Primary Human Osteoblasts Onto Microrough Titanium Surface.

OBJECTIVE: The aim of this study was to evaluate in vitro the behavior and the biocompatibility of primary human osteoblasts (HOs) grown onto different implant surface. METHODS AND MATERIALS: HOs were cultured onto sandblasted/acid-etched (control group) and sandblasted/acid-etched followed by coating with inorganic ions (test group) experimental titanium discs. At established times, SEM analysis, LDH assay, MTT assay, and enzyme-linked immunosorbent assay for type 1 collagen, interleukin (IL)-6, and PGE2 secretion were performed. RESULTS: Both surfaces promote HOs adhesion and proliferation. After 21 days, cells on test surfaces are well spread, flattened, and attached by cellular extensions, whereas cells on control discs appear mainly elongated. Lower LDH levels and higher values of MTT assay are recorded for cells on test respect to control surfaces at each experimental time. Type 1 collagen release increases until 14 days, significantly decreasing at day 21 in cells grown on both surfaces. IL-6 and PGE2 secretion shows a peak in control group samples at day 7, whereas their levels do not significantly modify in both groups at days 14 and 21. CONCLUSION: Results indicate that the test group surface is more biocompatible, well tolerated, and suitable for supporting osteoblasts growth and proliferation.

Zoledronic acid at subtoxic dose extends osteoblastic stage span of primary human osteoblasts.

OBJECTIVE: This study aimed to check the effect of zoledronic acid (ZA) at subtoxic dose on human osteoblasts (HOs) in terms of cell viability, apoptosis occurrence, and differentiation induction. ZA belongs to the family of bisphosphonates (BPs), largely used in the clinical practice for the treatment of bone diseases, often associated with jaw osteonecrosis onset. Their pharmacological action consists in the direct block of the osteoclast-mediated bone resorption along with indirect action on osteoblasts. MATERIALS AND METHODS: HOs were treated choosing the highest limit concentration (10(-5) M) which does not induce toxic effects. Live/dead staining, flow cytometry, mitochondrial membrane potential assay, osteocalcin western blotting, gp38 RT-PCR, collagen type I, PGE2, and IL-6 ELISA assays were performed. RESULTS: Similar viability level between control and ZA-treated samples is found along with no significant increase of apoptotic and necrotic cells in ZA-treated sample. To establish if an early apoptotic pathway was triggered, Bax expression and mitochondrial membrane potential were evaluated finding a higher protein expression in control sample and a good integrity of mitochondrial membrane in both experimental points. Type I collagen secretion and alkaline phosphatase (ALP) activity appear increased in ZA-treated sample, osteocalcin expression level is reduced in ZA-treated cells, whereas no modifications of gp38 mRNA level are evidenced. No statistical differences are identified in PGE2 secretion level whereas IL-6 secretion is lower in ZA-treated HOs with respect to control ones. CONCLUSIONS: These results highlight that ZA, delaying the osteoblastic differentiation process versus the osteocytic lineage, strengthens its pharmacological activity enhancing bone density. CLINICAL RELEVANCE: The knowledge of ZA effects on osteoblasts at subtoxic dose allows to improve therapeutic protocols in order to strengthen drug pharmacological activity through a combined action on both osteoclastic and osteoblastic cells.

Nitric oxide-mediated cytotoxic effect induced by zoledronic acid treatment on human gingival fibroblasts.

OBJECTIVES: The aim of our work was to evaluate the role of nitric oxide (NO) in the in vitro response of human gingival fibroblasts (HGFs) to 1, 5, 10, and 100 µM doses of zoledronic acid (ZA), a bisphosphonate largely used in the clinical practice and for which several adverse effects are reported. MATERIALS AND METHODS: Phase contrast microscopy and live/dead staining were used to evaluate HGFs morphology; cell viability, collagen type I and interleukin 6 (IL-6) secretion were evaluated by 3-[4,5-dimethyl-thiazol-2-yl-]-2,5-diphenyl tetrazolium bromide (MTT) and enzyme-linked immunosorbent assay (ELISA) assays. Reactive oxygen species (ROS) production and mitochondrial membrane potential were evaluated by flow cytometry; NO production and NOS activity by spectrophotometric analysis; endothelial NOS (eNOS) and neuronal NOS (nNOS) expression by immunofluorescence. RESULTS: Viable fibroblasts are evidenced in control sample while floating dead cells and cells close to detachment phase in ZA-treated sample, in agreement with decreased level of collagen type I. Control sample shows higher number of viable cells respect to ZA-treated one and ROS production increases when ZA is added. Released NO in ZA-treated sample appears higher and NO overproduction is related to increased nNOS activity. IL-6 secretion level is higher in ZA-treated sample than in control one. CONCLUSIONS: Our results suggest ROS involvement in NO overproduction, due to nNOS recruitment, both at low and high doses. In turn, NO release seems to be able to trigger the inflammatory response only when high doses are administered, thus confirming the ZA cytotoxic effect on HGFs. CLINICAL RELEVANCE: The knowledge of ZA-mediated cytotoxicity mechanisms on HGFs allows to better understand drug pharmacological activity.

Equine and porcine bone substitutes in maxillary sinus augmentation: a histological and immunohistochemical analysis of VEGF expression.

The aim of this work was to investigate the morphological structure and the expression of vascular endothelial growth factor (VEGF) after maxillary sinus augmentation through equine and porcine bone substitutes in humans. Ten patients showing edentulous posterior maxilla underwent maxillary sinus augmentation through particulate equine bone substitute and 10 patients through particulate porcine bone substitute. At the moment of implants insertion, 6 months after grafting, bone specimens were withdrawn and processed for morphological and immunohistochemical analyses. Notwithstanding the almost comparable clinical performances of both bone substitutes, histological results showed a better integration when an equine bone substitute was used compared to a porcine one. In particular, evident signs of particles resorption were observed in equine bone substitute group specimens compared to porcine ones. Immunohistochemical analysis showed a statistically significant increase of VEGF expression in equine compared to porcine bone substitute group specimens. These results showed both bone substitutes to achieve comparable clinical performance, indicating their successful use for bone regenerative procedures. However, in the same experimental time, equine group specimens showed evident resorption phenomena, whereas no or little signs of resorption were evident in the porcine group specimens. However, a more rapid and intense vascularization was achieved in equine bone substitute group, as demonstrated by immunohistochemical analysis for VEGF expression. Even if differences in vascularization significantly affect the clinical performance of a heterologous bone substitute, its ability to be resorbed is also very important in influencing long-term integration and long-term predictability of implant-prosthetic rehabilitation in regenerated sites.

Relationship between the surface energy and the histologic results of different titanium surfaces.

The aim of this study was to evaluate, through in vitro and in vivo studies, the existence of a relationship between surface energy, for wettability, and the clinical behavior of dental implants with different surfaces, one with a surface treated by sandblasting with titanium oxide microparticles followed by acid-etching treatment (experimental group) and another with a machined surface (control group). For the in vitro tests, a total of 30 titanium disks (15 disks for each group) were evaluated by scanning electron microscopy and dispersive energy spectroscopy and for surface roughness and wettability. For the in vivo tests, a total of 24 implants (12 implants for each group) were inserted in the tibiae of 6 rabbits and were removed after 30 and 60 days for histologic analysis. The results showed that the implants with the experimental surface presented a low wettability, and it also resulted in highly stimulated new bone formation in vivo, when compared with the control group dental implant. As for the bone formation, differences between the different surfaces seemed evident, both in quantity and in quality, as implants from the experimental group showed a higher new bone deposition than that from the control group. Thus, in vitro and in vivo tests demonstrated an excellent biologic response of the surfaces treated by sandblasting with microparticles of titanium oxide followed by acid etching.

Characterizing scientific production of Italian Oral Surgery professionals through evaluation of bibliometric indices.

The aim of this study was to characterize the scientific production of Italian Oral Surgery professionals by evaluating different bibliometric indices. The bibliometric evaluation was conducted on the Scopus Database upon all the Active Members joining three important Italian scientific societies in Oral Surgery (SIdCO, SIO, and SICOI). The scientific production was analysed by considering the number of total publications, number of total citations, h-index, and hc-index. Moreover, the overall sample was divided into two groups (Academics and Not Academics), according to the fact the professionals had or not a university position, and then into sub-groups according to the different career lengths. Statistical analyses were performed to compare the scientific productivity amongst groups. For all the considered parameters a lack of homogeneity between groups was reported, and significantly greater mean values were recorded for the Academics compared to the Not Academics Group. Moreover, the h-index values increased more regularly as the career length progressed than the hc-index values, even if the last seemed to be less variable. h- and hc-indices are both stable bibliometric parameters, but as the hc-index values are related not only to the number of citation but also to their age, it seems to be less influenced by the authors' career length. Bibliometric analysis of the scientific production in dentistry may facilitate the recognition of factors that may further enhance research activity and clinical performance and be useful for a comparative assessment of authors or research groups in terms of quality and quantity of the scientific production.

Proliferation and adhesion capability of human gingival fibroblasts onto zirconia, lithium disilicate and feldspathic veneering ceramic in vitro.

Human gingival fibroblasts (HGFs) were cultured onto CAD/CAM zirconia (Group A), CAD/CAM zirconia after polishing (Group B), CAD/CAM lithium disilicate after polishing (Group C), and feldspathic ceramic (Group D) to evaluate their proliferation and adhesion potential. After 3 h, HGF adhesion was similar in all groups. Later, HGFs closely adhered to surfaces, particularly onto groups B, C and D, acquiring an elongated shape. Proliferation assay showed no differences in cell viability among the groups after 24 h, while significant increase was shown after 72 h in Groups B and C. After 24 h, similar Collagen I levels were found in all groups, while after 72 h Groups B and C revealed a deep reduction in respect to the 24 h level. In vitro, HGF behavior may reflect variability in soft tissue response to different surface materials for prosthetic restorations, and support that polished zirconia is able to achieve a better integration in vivo in respect to the other materials.

Synthetic bone substitute engineered with amniotic epithelial cells enhances bone regeneration after maxillary sinus augmentation.

BACKGROUND: Evidence has been provided that a cell-based therapy combined with the use of bioactive materials may significantly improve bone regeneration prior to dental implant, although the identification of an ideal source of progenitor/stem cells remains to be determined. AIM: In the present research, the bone regenerative property of an emerging source of progenitor cells, the amniotic epithelial cells (AEC), loaded on a calcium-phosphate synthetic bone substitute, made by direct rapid prototyping (rPT) technique, was evaluated in an animal study. MATERIAL AND METHODS: Two blocks of synthetic bone substitute (∼0.14 cm(3)), alone or engineered with 1×10(6) ovine AEC (oAEC), were grafted bilaterally into maxillary sinuses of six adult sheep, an animal model chosen for its high translational value in dentistry. The sheep were then randomly divided into two groups and sacrificed at 45 and 90 days post implantation (p.i.). Tissue regeneration was evaluated in the sinus explants by micro-computer tomography (micro-CT), morphological, morphometric and biochemical analyses. RESULTS AND CONCLUSIONS: The obtained data suggest that scaffold integration and bone deposition are positively influenced by allotransplantated oAEC. Sinus explants derived from sheep grafted with oAEC engineered scaffolds displayed a reduced fibrotic reaction, a limited inflammatory response and an accelerated process of angiogenesis. In addition, the presence of oAEC significantly stimulated osteogenesis either by enhancing bone deposition or making more extent the foci of bone nucleation. Besides the modulatory role played by oAEC in the crucial events successfully guiding tissue regeneration (angiogenesis, vascular endothelial growth factor expression and inflammation), data provided herein show that oAEC were also able to directly participate in the process of bone deposition, as suggested by the presence of oAEC entrapped within the newly deposited osteoid matrix and by their ability to switch-on the expression of a specific bone-related protein (osteocalcin, OCN) when transplanted into host tissues.

Histological evaluation of fresh frozen bone integration at different experimental times.

The aim of this work was to investigate, through histological evaluation, the in vivo behavior of fresh frozen bone (FFB) used as particulate bone substitute in intraoral regenerative procedures. A total of 10 patients (group 1) received particulate FFB graft for bone regeneration in postextractive sockets, and 10 (group 2) underwent maxillary sinus augmentation by using the same bone substitute as filling. Fresh frozen bone was supplied from the Tissue Bank of the Veneto Region, Treviso Section.Healing was uneventful for all the patients and was monitored by periodical radiographs. Patients were scheduled for implant insertion according to the radiographic aspect. However, the mean healing time for group 1 was 45 days, whereas for group 2 patients, it was 100 days. At the moment of implant insertion, bone specimens were collected at the site of implant placement, from both groups and processed for histological analysis.Histological analysis after hematoxylin-eosin staining obtained from group 1 patients showed the presence of newly formed bone tissue, still well distinguishable from the grafted bone substitute. In samples from group 2 patients, a better integration could be recognized associated with active bone remodeling phenomena.These results showed a good integration of the considered FFB graft within the host tissue both at 45 and 100 days after grafting, displaying this biomaterial as suitable for preimplant regenerative procedures.

Immunohistochemical analysis of matrix metalloproteinase-9, vascular endothelial growth factor, bone sialoprotein and i-nitric oxide synthase in calvaria vs. iliac crest bone grafts.

OBJECTIVES: The aim of this study was to investigate, in parallel to clinical and histological modifications, the expression of specific proteins involved in different extraoral autologous bone grafts integration in humans. MATERIAL AND METHODS: Patients needing oral rehabilitation of posterior maxilla, with inadequate bone volume for implant placement, received bone grafts from calvaria (Group 1) and iliac crest (Group 2), respectively. From five patients from each group, with a total of 10 subjects, bone biopsy specimens were collected at two different experimental time points: at bone blocks withdrawal for grafting (T0), from donor sites, and after 4 months, from reconstructed sites. Samples were processed for light microscope and immunohistochemical analyses to evaluate MMP9, VEGF, BSP, iNOS expression. RESULTS: Morphological analysis of T0 calvaria evidenced areas of extracellular matrix, uniformly stained and organized in concentric mineralized lamellae edging few vascular canals, while T0 iliac crest showed greater cellularity compared to calvaria, with rare mineralized areas, surrounding wide bone marrow lacunae. In T1, Group 1 samples showed large areas of extracellular matrix, uniformly stained, at the same time as Group 2 samples disclosed few areas of mineralized tissue. Although no significant differences were found in proteins expression among calvaria and iliac crest T0 samples, MMP9, VEGF and BSP expression at T1 were discovered higher in Group 1 samples than in Group 2 ones, while iNOS expression increased in Group 2 samples compared to the others. In any group, molecules expression increased passing from T0 to T1. CONCLUSION: These findings suggested that, even though clinically both extraoral sources of autologous bone could be considered suitable for grafting in case of large oral rehabilitation, some differences might be detected microscopically and biologically. Calvaria bone graft seemed to enhance not only the quantity of bone tissue at the defect site, but also its quality, better than iliac crest bone do. Then, while both grafts appeared to promote a suitable neoangiogenesis, as showed by morphological analysis and by MMP9 and VEGF expression, in terms of new bone formation and lack of occurrence of inflammatory events, calvaria could be considered a more suitable donor site for bone grafts.