Biomolecular, Histological, Clinical, and Radiological Analyses of Dental Implant Bone Sites Prepared Using Magnetic Mallet Technology: A Pilot Study in Animals.

BACKGROUND: A new instrumentation exploiting magneto-dynamic technology (mallet) proposed for implant site preparation was investigated. METHODS: In the tibias of three minipigs, two sites were prepared by mallet and two by drill technique. Primary stability (ISQ) was detected after implant positioning (T0) and at 14 days (T14). X-rays and computed tomography were performed. At T14, bone samples were utilized for histological and biomolecular analyses. RESULTS: In mallet sites, histological evaluations evidenced a significant increase in the newly formed bone, osteoblast number, and a smaller quantity of fibrous tissue. These results agree with the significant BMP-4 augmentation and the positive trend in other osteogenic factors (biological and radiological investigations). Major, albeit IL-10-controlled, inflammation was present. For both techniques, at T14 a significant ISQ increase was evidenced, but no significant difference was observed at T0 and T14 between the mallet and drill techniques. In mallet sites, lateral bone condensation was observed on computed tomography. CONCLUSIONS: Using biological, histological, clinical, and radiological analyses, this study first shows that the mallet technique is effective for implant site preparation. Based on its ability to cause osseocondensation and improve newly formed bone, mallet technology should be chosen in all clinical cases of poor bone quality.

Role of rhBMP-7, Fibronectin, And Type I Collagen in Dental Implant Osseointegration Process: An Initial Pilot Study on Minipig Animals.

BACKGROUND: The biological factors involved in dental implant osseointegration need to be investigated to improve implant success. METHODS: Twenty-four implants were inserted into the tibias of six minipigs. Bone samples were obtained at 7, 14, and 56 days. Biomolecular analyses evaluated mRNA of BMP-4, -7, Transforming Growth Factor-ß2, Interleukin-1ß, and Osteocalcin in sites treated with rhBMP-7, Type 1 Collagen, or Fibronectin (FN). Inflammation and osteogenesis were evaluated by histological analyses. RESULTS: At 7 and 14 days, BMP-4 and BMP-7 increased in the sites prepared with rhBMP-7 and FN. BMP-7 remained greater at 56 days in rhBMP-7 and FN sites. BPM-4 at 7 and 14 days increased in Type 1 Collagen sites; BMP-7 increased from day 14. FN increased the TGF-ß2 at all experimental times, whilst the rhBMP-7 only did so up to 7 days. IL-1ß increased only in collagen-treated sites from 14 days. Osteocalcin was high in FN-treated sites. Neutrophilic granulocytes characterized the inflammatory infiltrate at 7 days, and mononuclear cells at 14 and 56 days. CONCLUSIONS: This initial pilot study, in a novel way, evidenced that Type 1 Collagen induced inflammation and did not stimulate bone production; conversely FN or rhBMP-7 showed neo-osteogenetic and anti-inflammatory properties when directly added into implant bone site.

Microbiopsy a novel sampling technique to early detect dysplastic/malignant alterations in oral mucosal lesions: practicability by general dentists.

BACKGROUND: When used in oral medicine clinics, microbiopsy is able to obtain tissue fragments suitable for a highly sensitive first-level diagnosis of dysplastic/malignant alterations in oral mucosal lesions. If feasible by general dentists, this sampling technique could reduce the diagnostic delay for oral malignant and premalignant lesions. This study assesses the adequacy of microbiopsy samples when taken by general dentists. METHODS: Fifty dentists, without specific training on oral medicine, volunteered for enrolment. They were given brief training and asked to prospectively sample any mucosal lesion observed during their routine practice. The sample adequacy features were assessed. RESULTS: The dentists sampled 152 lesions; there were 92.1% of adequate samples (140/152), and the BMZ was visible in 78.6% of these (110/140). Neither the clinical aspect nor lesion site affected either the adequacy or the presence of BMZ. CONCLUSIONS: The high adequacy rate observed and the advantages histological specimens have over cytological ones go to support the feasibility of microbiopsy taken by general dentists for the characterization of oral mucosal lesions and in selecting those requiring further assessment in specialized oral medicine centres.

Evidence for a possible anatomical subsite-mediated effect of tobacco in oral potentially malignant disorders and carcinoma.

PURPOSE: To test the hypothesis that cigarette smokers develop oral potentially malignant disorders or carcinomas in preferential anatomical subsites. METHODS: The association of smoking habit with the presence of oral lesions in specific anatomical subsites was assessed in 123 patients using the odds ratio analysis. RESULTS: When compared to all the other subsites, the relative frequency of smokers with lesions was higher in the buccal mucosa and in the floor of the mouth (FOM) (P=0.002 and P=0.005), while it was lower in the tongue (P<0.0005). Smokers were about 7 years younger than non-smokers (P=0.008). CONCLUSIONS: The association of smoking and age suggests that smoking may contribute to generate a field of injury that leads to lesions in shorter periods than other causes. The stronger relationship of smoking with lesions in the buccal mucosa and FOM than in the tongue suggests that tissue characteristics mediate the effects of tobacco.

Liquid-based cytology in oral cavity squamous cell cancer.

PURPOSE OF REVIEW: Oral exfoliative cytology is a practical tool for early diagnosis of squamous cell carcinoma (OSCC) and potentially malignant lesion (OPML), but is not yet extensively used. A literature review evaluated conventional and liquid-based oral diagnostic cytology efficacy and efficiency. 'Special' techniques like liquid-based cytology, computer-assisted cytology, Oral CDx, DNA ploidy, immunocytochemistry, molecular analyses and microhistology were reviewed. RECENT FINDINGS: Cytology was useful when diagnosing OSCC and OPML. Oral CDx may assess dysplastic changes in clinically suspicious (class I) lesions, with doubtful efficacy in apparently innocuous (class II) lesions. Flow and/or image cytometry and immunocytochemistry can identify markers for the prediction of evolution of the OPML to OSCC. Molecular biology can detect the minimal residual clonal population of cancer cells in field cancerization and oral mucosa surgical margins. Microhistology is a reliable first level test in class II lesions for selected cases requiring surgical biopsy. SUMMARY: Conventional cytology helps in OSCC and OPML screening; liquid-based cytology gives better results, enhancing both sensitivity and specificity, and provides material for further investigation. Sampling with the 'curette technique' permits collection of 'accidental' tissue fragments used as microbiopsies and proved a useful first-level test for the management of class II OPML.

Oral cancer genesis and progression: DNA near-diploid aneuploidization and endoreduplication by high resolution flow cytometry.

Oral potentially malignant lesions (OPMLs) with dysplasia and aneuploidy are thought to have a high risk of progression into oral squamous cell carcinomas (OSCCs). Non-dysplastic "oral distant fields" (ODFs), characterized by clinically normal appearing mucosa sited at a distance from co-existing OPMLs, and non-dysplastic OPMLs may also represent an early pre-cancerous state. ODFs, OPMLs without and with dysplasia and OSCCs were investigated by high resolution DNA content flow cytometry (FCM). ODFs and OPMLs without dysplasia were DNA aneuploid respectively in 7/82 (8.5%) and 25/109 (23%) cases. "True normal oral mucosa" and human lymphocytes from healthy donors were DNA diploid in all cases and were used as sex specific DNA diploid controls. Dysplastic OPMLs and OSCCs were DNA aneuploid in 12/26 (46%) and 12/13 (92%) cases. The DNA aneuploid sublines were characterized by the DNA Index (DI not =1). Aneuploid sublines in ODFs and in non-dysplastic and dysplastic OPMLs were near-diploid (DI<1.4) respectively in all, 2/3 and 1/3 of the cases. DNA aneuploid OSCCs, instead, were characterized prevalently by multiple aneuploid sublines (67%), which were commonly (57%) high-aneuploid (DI> or =1.4). DNA near-diploid aneuploid sublines in ODFs and OPMLs appear as early events of the oral carcinogenesis in agreement with the concept of field effect. Near-diploid aneuploidization is likely to reflect mechanisms of loss of symmetry in the chromosome mitotic division. High DNA aneuploid and multiple sublines in OPMLs with dysplasia and OSCCs suggest, instead, mechanisms of "endoreduplication" of diploid and near-diploid aneuploid cells and chromosomal loss. High resolution DNA FCM seems to enable the separation of subsequent progression steps of the oral carcinogenesis.

Neuropathology of olfactory ensheathing cell transplantation into the brain of two amyotrophic lateral sclerosis (ALS) patients.

Although a large number of amyotrophic lateral sclerosis (ALS) patients have undergone transplantation procedures with olfactory ensheathing cells (OECs) in the Bejing Hospital, to our knowledge, no post-mortem neuropathologic analyses have been performed. We examined the post-mortem brain of two Italian patients affected by ALS who underwent cellular transplantation in Beijing with their consent. Our aim was to assess the events following the graft procedure to possibly support the rationale of the treatment strategy. The neuropathologic findings were analyzed on the basis of the limited awareness of the experimental conditions and discussed in relation to the safety, efficacy and long-term outcome of the transplanted cells. Islands of quiescent, undifferentiated cells within the delivery track persisting for up to 12 months-24 months were found. Prominent glial and inflammatory reaction around the delivery track strongly supports the encasement of the graft. Evidence of axonal regeneration, neuronal differentiation and myelination was not seen. The surgical procedure of implantation was not compatible with a neurotrophic effect. The OEC transplantation did not modify the neuropathology of ALS in the two patients. In conclusion, the present neuropathologic analysis does not support a beneficial effect of fetal OEC implantation into the frontal lobes of ALS patients.

DNA aneuploidy and dysplasia in oral potentially malignant disorders: association with cigarette smoking and site.

To date there are still no reliable biomarkers for oral potentially malignant disorders (PMDs) to predict the risk of progression to squamous cell carcinoma (SCC). Within a prospective clinical trial of patients with PMDs, DNA content flow cytometry (DNA FCM) was evaluated for 60 PMDs using fresh samples obtained by a dermatological curette. There were 6/42 PMDs without dysplasia, but with DNA aneuploidy, versus 8/18 with both dysplasia and aneuploidy (p=0.02). When the tongue and the buccal mucosa, the two most common sites in the present series of cases were compared, dysplastic PMDs were mainly located on the tongue (p=0.01). Tobacco smokers, who preferentially developed PMDs in the buccal mucosa at a younger age than non-smokers (p=0.002), had fewer dysplastic PMDs than did non-smokers (p=0.01). Dysplasia was significantly linked to DNA aneuploidy (p=0.03) in smokers. The present data suggest that aneuploidy is an early event in oral carcinogenesis and that the influence of tobacco varies according to subsite and patient age. When DNA FCM of PMD samples are obtained by curette scraping, extensive areas can be covered with a minimally invasive, rapid, inexpensive procedure. Moreover DNA FCM of these samples appears easy amenable to routine analysis. Further research on larger numbers of PMDs should be carried out to determine whether DNA FCM plays a role in the prediction of risk of PMD transformation.

Oral potentially malignant lesions: first-level micro-histological diagnosis from tissue fragments sampled in liquid-based diagnostic cytology.

BACKGROUND: Scalpel biopsy may under-diagnose oral dysplasia/carcinoma in potentially malignant lesions (PMLs) because samples represent only one or a few sites. It is possible that small tissue specimens obtained from over the whole area of PMLs, by scraping with a dermatological curette, could be treated histologically and used as 'micro' biopsies. This study values the accuracy of micro-biopsies in the detection of dysplasia/carcinoma in oral PMLs. METHODS: A prospective study was carried out on 164 patients with PMLs, with both scalpel and micro-biopsies, for the presence of dysplasia/carcinoma. The most severe diagnosis (obtained by either method) was used as the reference standard. The presence/absence of the basement membrane zone (BMZ) in the micro-biopsy specimens correlated with the site, the clinical features of the PMLs and the operator. RESULTS: Micro-biopsy gave six of 164 (3.66%) inadequate specimens. Of 158 of 164 adequate samples, dysplasia/carcinoma was diagnosed in 85 of 158 cases; micro-biopsy diagnosis was in agreement with scalpel biopsy in 144 of 158 (91.14%) cases and showed a better sensitivity than did scalpel biopsy (97.65% vs. 85.88%), corresponding to two of 158 false-negative cases by micro-biopsy vs. 12 of 158 by scalpel biopsy. The BMZ was observed in 110 of 158 (69.62%) of all micro-biopsies and had no relationship with the sampling site, the clinical features of the PMLs or the operator. CONCLUSIONS: The negative predictive value (97.33%) suggests that micro-biopsy may well be an effective first-level diagnostic procedure for PMLs (especially in follow-ups and multiple lesions); moreover, in carcinoma (17% of cases) a definitive diagnosis could be made without further investigation.

Cytokines and growth factors involved in the osseointegration of oral titanium implants positioned using piezoelectric bone surgery versus a drill technique: a pilot study in minipigs.

BACKGROUND: Most dental implants are positioned using a drilling surgery technique. However, dentistry recently experienced the implementation of piezoelectric surgery. This technique was introduced to overcome some of the limitations involving rotating instruments in bone surgery. This study used biomolecular and histologic analyses to compare the osseointegration of porous implants positioned using traditional drills versus the piezoelectric bone surgery technique. METHODS: Porous titanium implants were inserted into minipig tibias. Histomorphology and levels of bone morphogenetic protein (BMP)-4, transforming growth factor (TGF)-beta2, tumor necrosis factor-alpha, and interleukin-1beta and -10 were evaluated in the peri-implant osseous samples. RESULTS: Histomorphological analyses demonstrated that more inflammatory cells were present in samples from drilled sites. Also, neo-osteogenesis was consistently more active in bone samples from the implant sites that were prepared using piezoelectric bone surgery. Moreover, bone around the implants treated with the piezoelectric bone surgery technique showed an earlier increase in BMP-4 and TGF-beta2 proteins as well as a reduction in proinflammatory cytokines. CONCLUSION: Piezoelectric bone surgery appears to be more efficient in the first phases of bone healing; it induced an earlier increase in BMPs, controlled the inflammatory process better, and stimulated bone remodeling as early as 56 days post-treatment.

Biological factors involved in the osseointegration of oral titanium implants with different surfaces: a pilot study in minipigs.

BACKGROUND: The stability of titanium implants is determined by the rigid load-bearing connections that are formed by the bone, a process that involves a complex network of cells, pro- and anti-inflammatory mediators, and growth factors. The osseointegration processes at the interfaces of machined and porous implants were studied using molecular and histological techniques. METHODS: Two machined and two porous titanium implants were inserted into the tibiae of four minipigs. The animals were sacrificed at 15, 30, 60, and 90 days post-implantation. The levels of bone morphogenetic protein (BMP)-4, transforming growth factor (TGF)-beta1, and tumor necrosis factor (TNF)-alpha were quantified in the peri-implant osseous samples. The levels of interleukin (IL)-1beta, IL-6, IL-10, and TNF-alpha in the serum were also assessed. RESULTS: Histomorphological analysis showed evidence of bone ossification around the porous implant at 60 days. Surrounding the machined implants, highly sclerotic fibrous pads started the healing response at 90 days, and the levels of TGF-beta1 and BMP-4 began to increase at 60 days, at which time bone ossification around the porous implants was already evident. TNF-alpha was not present in the bone next to the implants. The serum levels of cytokines IL-1beta, IL-6, and IL-10 were not increased. The serum level of TNF-alpha increased during the healing process. CONCLUSIONS: We observed that the levels of BMP-4 and TGF-beta1, which play essential roles in the osteogenesis process, increased earlier around the porous implants than around the machined implants. Similarly, the ossification process was initiated earlier at the surfaces of the porous implants than at the surfaces of the machined implants.

Assessment of specimen adequacy reproducibility: an Italian experience.

Interobserver disagreement on smear adequacy may influence the evaluation of the performance of samplers as well as Pap test sensitivity and follow-up. In 1998, the Italian Group for Cervical Cancer Screening (GISCi) promoted a study on the reproducibility of adequacy criteria using a modified version of the Bethesda system. A set of 200 smears was circulated among six Italian laboratories situated in different parts of the country. For each smear, participants were requested to provide a summary judgment on its adequacy and on the cause(s) of inadequacy, if any. Agreement was measured using kappa-type statistics. The agreement among laboratories was generally good. In comparisons, among five laboratories, kappa values ranged from 0.47 to 0.66. At the consensus meeting on 42 slides, on which at least 2 laboratories dissented from the majority, agreement was reached unanimously for 31 reviewed slides and among 5-6 centers for 11. In this article, some guidance is given in order to attribute to one of the two categories satisfactory/unsatisfactory those smears that have been traditionally considered as candidates for the category of "satisfactory but limited by em leader " (SBLB). New Italian guidelines on adequacy proposed the GISCi are presented and the recommendation is made to eliminate the SBLB category.

Proliferative activity is the most significant predictor of recurrence in noninvasive papillary urothelial neoplasms of low malignant potential and grade 1 papillary carcinomas of the bladder.

BACKGROUND: Recurrence of transitional cell carcinoma of the bladder cannot be predicted accurately by traditional criteria alone. This study examined the value of cell proliferative activity, morphometry, and expression of p53, c-erbB-2, and bcl-2 oncogenes in predicting recurrence of superficial papillary urothelial neoplasms of low malignant potential (LMP) and Grade 1 (G1) papillary carcinomas of the bladder. METHODS: Sixty-two patients (mean age, 62 years) with newly diagnosed superficial pTa bladder tumors (19 LMP, and 43 G1) were analyzed retrospectively. All patients underwent transurethral resection (TUR). Median follow-up was 69 months. Serial sections from formalin-fixed, paraffin-embedded material at initial TUR were stained with monoclonal antibodies (MoAbs) DO7, CB11, and bcl-2-124. Cell proliferation was assessed by MIB-1 MoAb, the quantity of argyrophilic nucleolar organizer region-associated proteins (AgNORs), and mitotic count. RESULTS: Of the 62 patients, 42 (67.7%) had one or more recurrences. Recurrence rates were higher in MIB-1 (P < 0.0001) and p53 immunopositive cases (P = 0.02), when the mitotic count was greater than 5 (P = 0.004), and in G1 carcinomas (P = 0.04). In univariate analysis, the disease-free period was shorter for MIB-1 (P < 0.0001) and p53 immunopositive (P = 0.0001) cases, for cases with high AgNOR quantity (P = 0.04), mitotic count greater than 5 (P = 0.01), and in G1 carcinomas (P = 0.002). In multivariate analysis, only MIB-1 immunoreactivity retained independent prognostic significance. CONCLUSIONS: Despite the small cohort, the results confirm the prognostic value of cell proliferation and p53 expression in patients with bladder neoplasms. The results also indicate that MIB-1 immunopositivity is the most significant predictor of recurrence and disease-free survival in superficial LMP and G1 papillary bladder carcinomas.