Giuseppe Spinelli

Retrospective Study of Standard-Diameter Implants Inserted Into Allografts

PURPOSE In the last decade, several investigators reported that standard-diameter implants (SDIs) achieved excellent results. However, no report is available regarding SDIs inserted into fresh-frozen bone (FFB). We conducted a retrospective study on a series of SDIs (diameter, 3.75 mm) inserted into homologous FFB to evaluate their clinical outcome. MATERIALS AND METHODS The SDIs inserted with FFB were analyzed. Several variables were investigated regarding patients, anatomic sites, implants, and prosthetic restoration. Implant failure and peri-implant bone resorption were considered predictors of clinical outcome. A Kaplan-Meier algorithm and Cox regression were performed to detect those variables statistically associated with clinical outcomes. RESULTS One hundred thirty-three SDIs were inserted in 41 patients. Implant length ranged from 10 to 15 mm. Implants were inserted to replace 6 incisors, 13 cuspids, 60 premolars, and 54 molars. The mean follow-up was 23 months. Only 1 of 133 implants was lost (ie, survival rate=99.2%), and no differences were detected among study variables. On the contrary, crestal bone resorption correlates with type of prosthetic restoration, with a better outcome for removable dentures. CONCLUSION The SDIs had high survival and success rates, similar to those reported in previous studies of 2-stage procedures in nongrafted bone. The SDIs inserted into FFB are reliable, although a greater marginal bone loss is to be expected if fixed prosthetic restorations are used.

PerioGlas regulates osteoblast RNA interfering.

PURPOSE PerioGlas (PG) is an alloplastic material that has been used for grafting periodontal osseous defects since the 1990s. In animal models, it has been proven that PG achieves histologically good repairs of surgically created defects. In clinical trials, PG is effective as an adjunct to conventional surgery in the treatment of intrabony defects; however, how PG alters osteoblast activity to promote bone formation is poorly understood. We therefore attempted to address this question by using microRNA (miRNA) microarray techniques to investigate the translation process in osteoblasts exposed to PG. MATERIALS AND METHODS By using miRNA microarrays containing 329 probes designed from human miRNA sequences, we identified several miRNA whose expression was significantly modified in osteoblast-like cell lines (MG-63) cultured with PG. RESULTS There were ten up-regulated miRNA (mir-337, mir-377, mir-9, mir-516, mir-515-3p, mir-496, mir-200b, mir-489, mir-25, mir-423) and two down-regulated miRNA (mir-26a, mir-30d). CONCLUSION PG acts on miRNAs, which in turn regulate several messengers. Among them there are mRNAs related to bone formation and skeletal and cartilage development. The vast majority of detected genes are down-regulated, and some are homeobox genes like NOG, EN1, and CHRD. Other down-regulated genes are receptors (like GHRHR) and extracellular matrix proteins (like COMP). Although the exact mechanism of PG action on osteoblasts is still incompletely understood, these data demonstrate that PG has not only an osteoconductive effect, but also regulates bone formation.

Absence of Simian virus 40, BK, and JC polyomavirus DNA in squamous cell carcinoma limited to the oral cavity

Head and neck squamous cell carcinomas (SCCs) are among the most aggressive types of cancer. The Simian virus 40 (SV40), which is a polyomavirus known for its oncogenic potential, was found as a contaminant of oral vaccines and has been related to human pleomorphic adenoma in the parotid gland. The aim of this study was to evaluate the presence of SV40 and 2 human polyomaviruses—BK virus (BKV) and JC virus (JCV)—in a large sample of SCCs of the oral cavity.

Lack of association between common polymorphisms of epidermal growth factor receptors and nonsyndromic cleft lip with or without cleft palate.

OBJECTIVES Nonsyndromic cleft lip with or without cleft palate (CL/P) is a frequent craniofacial malformation with a complex aetiology. Since the first report of an association between DNA sequence variants at the transforming growth factor alpha gene (TGFA) and nonsyndromic oral clefts, several studies have been carried out, which have produced conflicting results. Overall, TGFA is considered as a genetic clefting modifier in humans. Murine models indicate that the Tgfa product (tgfalpha), as well as its receptor (Egfr), actively participates in palate development. Notably, Egfr null mice showed an increased incidence in orofacial clefts. In the present study, genes which code for subunits of epidermal growth factor receptors (EGFRs) have been considered as candidate genes for CL/P. METHODS A family based investigation was performed using a sample of 239 case/parent triads. The aim was to test for an allelic association between common non-synonymous polymorphisms in EGFR genes and CL/P. RESULTS AND CONCLUSION The results did not suggest any evidence of a link between the investigated polymorphisms and CL/P, however the involvement of different polymorphisms or mutations in such genes cannot be excluded.

Incidence of low risk human papillomavirus in oral cancer: a real time PCR study on 278 patients.

Squamous cell carcinoma is the most frequent malignant tumour of the oral cavity. It is widely known that tobacco and alcohol consumption are the major causes of the development of oral squamous cell carcinoma (OSCC). The human papilloma virus infection has also been postulated as a risk factor for squamous cell carcinoma, although conflicting results have been reported. The aim of this study is to evaluate the presence of high-risk and low-risk type human papillomavirus in a large sample of squamous cell carcinoma limited to the oral cavity by means of quantitative real-time polymerase chain reaction. Data were obtained from 278 squamous cell carcinoma limited to oral cavity proper. Sequencing revealed that 5 samples were positive for HPV type 16, 5 for HPV type 11, and 1 for HPV type 6. Human papillomavirus 11 was detected in 5 tumours out of the 278 examined. The prevalence rate for Human papillomavirus 11 was 1.8% (C.I. 0.7–3.9). The matched case-controls analysis indicated that the prevalence among controls did not significantly differ with respect to cases and that Human papillomavirus 11 alone did not correlate with squamous cell carcinoma.

Analysis and structural examination of screw loosening in oral implants.

Biological and technical failures of implants have already been reported. Mechanical factors are certainly of importance in implant failures, even if their exact nature has not yet been established. The abutment screw fracture or loosening represents a rare, but quite unpleasant failure. The aim of the present research is an analysis and structural examination of screw thread or abutment. In this study broken screws were excluded. A total of 58 screw thread loosening were observed, 5 Branemark, (Nobel Biocare, Gothenburg, Sweden) 4 Implant Innovation (Riverside Drive Palm Beach Gardens, FL, USA) and 7 Restore (Lifecore Biomedical, Chaska, Minnesota, USA) and 42 T.B.R. implant (Benax, Ancona, Italy). The loosened abutment screws were retrieved and analyzed under SEM. Many alterations and deformations were present in concavities and convexities of screw threads.

LOH at PDCD4, CTNNB1, and CASP4 loci contributes to stage progression of oral cancer.

Squamous cell carcinoma is the most frequent malignant tumor of the oral cavity. Markers of tumor progression that could help to define diagnosis, plan treatment and implement prognosis have still to be identified. Seven candidate markers for tumor progression were investigated using a loss of heterozygosity (LOH) assay. The sample was made up of 51 squamous cell carcinoma and adjacent normal tissues from the same patients. LOH at one, or more, markers was a relatively frequent event that was observed in 53% of tumors. The number of losses detected in each tumor was significantly associated with tumor severity. Significant association between UICC stage grouping and LOH was found for 3 gene loci: programmed cell death 4 (PDCD4), catenin beta 1 (CTNNB1), and caspase 4 (CASP4). No association between allelic loss and the occurrence of lymph node metastasis was found for any of the seven investigated loci. Overall, LOH contributes to tumor progression of oral SCC. A specific role for PDCD4, CTNNB1, and CASP4 was found.

Osteoplant acts on stem cells derived from peripheral blood

Objectives: The osteoplant is an equine, flexible, heterologous, deantigenic, cortical, and spongy bone tissue, totally reabsorbable, used for implantation of bone tissue, to restore skeletal, even weight-bearing structures. However, how the osteoplant alters osteoblast activity to promote bone formation is poorly understood. Materials and Methods: To study how the osteoplant induces osteoblast differentiation in mesenchymal stem cells, the expression levels of bone-related genes, and mesenchymal stem cell markers are analyzed, using real time Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Results: The osteoplant causes induction of osteoblast transcriptional factors such as osterix (RUNX2), and of bone-related genes such as osteopontin (SPP1) and osteocalcin (BGLAP). In contrast the expression of ENG (CD105) is significantly decreased in stem cells treated with osteoplant, with respect to untreated cells, indicating the differentiation effect of this biomaterial on stem cells. Conclusion: The obtained results can be relevant to better understand the molecular mechanism of bone regeneration and as a model for comparing other materials with similar clinical effects.

Expression of β-catenin and γ-catenin in maxillary bone regeneration

β- and γ-catenin are components of catenin family involved in cadherin adhesion function. Recently it has been shown that this family is involved in other functions such as signaling and activation of transcription factors. The final goal of this study was to evaluate the role of β- and γ-catenin in bone cell physiology and bone regeneration. Formalin-fixed-paraffin embedded specimens of 15 human bone specimens after sinus lift were collected and examined by immunohistochemstry using primary antibodies against β- and γ-catenin. Staining intensity and cellular localization were evaluated. β and γ-catenin showed a very high level of expression in human bone tissues. In particular catenins were expressed in cells with morphological findings of osteoblasts in the areas of new bone formation at the junction between mineralized and unmineralized tissue, between osteoid matrix and bone. Osteoclasts showed also positivity for catenins. Osteocytes, cells located in lacunae of mature mineralized bone with function of bone vitality maintenance, showed no expression for catenins. Specimens characterized by high amount of catenins in osteoblasts at 1° month showed high grade of bone maturation at 3° month. Data demonstrated an overall involvement of catenins in human bone tissues and in particular during bone regeneration process. The presence of staining for β- and γ-catenin particularly in osteoblasts demonstrates a significant role of catenins in functions, other than in cadherin interaction, such as signaling and activation of transcription factors during differentiation of bone tissues.

Study of the 12q13 region in nonsyndromic cleft lip with or without cleft palate.

The 12q13 region has been suggested as a candidate locus for orofacial cleft by different investigators. In the present study we tested the region for linkage with non syndromic cleft lip with or without cleft palate in a collection of 39 Italian multigenerational families, using microsatellite markers. No evidence of linkage was detected between the marker map and NSCLP under different mode of inheritance nor with a nonparametric method. Formal level of linkage exclusion, were obtained for each point of the map. Genetic heterogeneity and the different impact of the candidate locus among populations could explain conflicting results obtained in different studies.