Diode laser surgery in the treatment of oral proliferative verrucous leukoplakia associated with HPV-16 infection / 대한악안면성형재건외과학회지

BACKGROUND: Proliferative verrucous leukoplakia (PVL) is an oral potentially malignant disorder, characterized by multifocal expression, progressive clinical evolution, and a high rate of malignant transformation. Evidence-based information regarding optimal PVL management is lacking, due to the paucity of data. The present report describes a case of PVL associated with HPV-16 infection and epithelial dysplasia treated by diode laser surgery, and the outcome of disease clinical remission over a 2-year follow-up period. CASE REPORT: A 61-year-old Caucasian male with oral verrucous hyperkeratosis presented for diagnosis. The lesions were localized on the maxillary gingiva and palatal alveolar ridge. Multiple biopsy specimens have been taken by mapping the keratotic lesion area. Microscopic examination was compatible with a diagnosis of PVL with focal mild dysplasia, localized in the right maxillary gingiva. Polymerase chain reaction (PCR) was done for human papillomavirus (HPV) detection which revealed presence of HPV DNA, and the genotype revealed HPV 16 in the sample. The PVL in the right gingival area was treated on an outpatient basis by excision with a diode laser. This approach resulted in good clinical response and decreased morbidity over a 2-year follow-up period. CONCLUSIONS: This case illustrates the benefit of a conservative approach by diode laser treatment than wide surgical excision for management of the PVL lesions associated with mild dysplasia and HPV-16 infection.

Distance between implants has a potential impact of crestal bone resorption

Around dental implants exists a "biologic width" of few millimeters that have to be preserved in order to not have adverse effect on soft and hard tissues around implant. Because the minimum distance between adjacent implants has not been determined yet, we therefore, decided to perform a retrospective study on a series of spiral family implants [SFIs] to verify the minimum inter-implants' distance that has an impact on crestal bone resorption. Fifty-nine implants were investigated with a mean follow-up of 14 months. Implant diameter was 3.75, 4.2, 5 and 6 mm in 11 [18.6%], 29 [49.2%], 17 [28.8%] and 2 [3.4%] SFIs. Implant length was shorter than 13 mm, equal to 13 mm and 16 mm in 23 [39%], 23 [39%] and 13 [22%] SFIs. Implants were inserted to replace 13 incisors [22%], 7 cuspids [11.9%], 30 premolars [50.8%] and 9 molars [15.3%]. Twenty-seven fixtures were inserted in post-extractive sockets and the remaining 32 in healed bone; 36 [61%] were immediately loaded. In addition to the above mentioned implant-related factors, several host- and surgery-factors were investigated. Independent samples T-test, univariate and multivariate analysis were used to detect those variables associated with the clinical outcome. Data were evaluated with a two steps statistical analysis [i.e. univariate and multivariate] after having grouped implants in two series: those with an implant-implant distance less of 1.8 mm and those with an implant-implants distance greater than 1.8 mm. In univariate analysis, post-extractive implants and number of prosthetic units were statistically significant. In multivariate analysis, only post-extractive implants have a significant adverse effect on crestal bone resorption. Adjacent implants inserted with a distance lower and higher than 1.8 mm have difference in crestal bone resorption but this difference is not statistically significant in a short period follow up. This could due to the specific implant used that has a reverse conical neck. No statistical difference was detected between implant subtypes. Post-extractive implant insertion is the major determinant in terms of peri-implant bone resorption in a short period follow-up

Bio-Oss[registered sign] acts on stem cells derived from peripheral blood

This study aims to study how Bio-Oss[registered sign] can induce osteoblast differentiation in mesenchymal stem cells, the expression levels of bone related genes and mesenchymal stem cells markers using real time Reverse Transcription-Polymerase Chain Reaction. PB-hMSCs stem preparations were obtained for gradient centrifugation from peripheral blood of healthy anonymous volunteers, using the Acuspin System-Histopaque 1077. The samples were then cultured for 7 days for RNA processing, and the expression was quantified using real time PCR. Bio-Oss[registered sign] caused an induction of osteoblast transcriptional factor like RUNX2 and of bone related genes; SPP1 and FOSL1. In contrast, the expression of ENG was significantly decreased in stem cells treated with Bio-Oss[registered sign] with respect of untreated cells, indicating the differentiation effect of this biomaterial on stem cells. The results obtained can be relevant to enhance the understanding of the molecular mechanism of bone regeneration and can act as a model for comparing other materials with similar clinical effects

Engipore acts on human bone marrow stem cells

Porous HA scaffolds are promising materials for tissue engineering because they offer a tridimensional support and serve as template for cell proliferation and at last tissue formation. Engipore provide a natural 3D scaffold with organic fibrous material in bone. However, how this material alters osteoblast activity to promote bone formation is poorly understood. To study how Engipore can induce osteoblast differentiation in mesenchymal stem cells, the expression levels of bone related genes and mesenchymal stem cells marker were analyzed. Engipore causes a significant induction of osteoblast transcriptional factors like SP7 and RUNX2 and of the bone-related gene osteocalcin [BGLAP]. The expression of CD105 was not significantly changed in stem cells treated with Engipore with respect to untreated cells, while SSP1 [osteopontin] was significantly down expressed thus reducing osteoclast activity. The obtained results can be relevant to better understand the molecular mechanism of bone regeneration

Perioglas [R] acts on human stem cells isolated from peripheral blood

PerioGlas [PG] is an alloplastic material used for grafting periodontal osseous defects since 1995. In animal models, it has been proven that PG achieves histologically good repair of surgically created defects. In clinical trials, PG was effective as an adjunct to conventional surgery in the treatment of intrabony defects. Because the molecular events due to PG that are able to alter osteoblast activity to promote bone formation are poorly understood, we investigated the expression of osteoblastic related genes in mesenchymal stem cells exposed to PG. The expression levels of bone related genes like RUNX2, SP7, SPP1, COL1A1, COL3A1, BGLAP, ALPL, and FOSL1 and mesenchymal stem cells marker [CD 105] were analyzed, using real time reverse transcription-polymerase chain reaction. Pearson's chi-square [chi[2]] test was used to detect markers with significant differences in gene expression. PG caused induction of osteoblast transcriptional factor [like RUNX2], bone related genes osteopontin [SPP1], osteocalcin [BGLAP] and alkaline phosphatase [ALPL]. All had statistical significant P values [< 0.05]. PG has a differentiation effect on mesenchymal stem cells derived from peripheral blood. The obtained results can be relevant to better understanding of the molecular mechanism of bone regeneration and as a model for comparing other materials with similar clinical effects

Success rate of long implants inserted in fresh frozen bone

To evaluate the clinical out come on a series of long implants inserted into homologue Fresh Frozen Bone [FFB]. This retrospective study was conducted in the period between December 2003 and December 2006, 33 patients were operated on at the Civil Hospital, Castelfranco Veneto, Italy and 85 LIs inserted. The mean follow-up period was 28 months. Implant diameter and length ranged from 3.3 to 5.0 mm and from 14 to 16 mm, respectively. No implants were lost [i.e. SRV = 100%] and no differences were detected among the studied variables, On the contrary, Cox regression showed that implant diameter [i.e. narrow - implants, diameter 3, 75 mm] and prosthetic restoration [i.e. removable dentures] correlated with a statistically significant lower delta IAJ [i.e. reduced crestal bone loss] and thus a better clinical outcome. FFB is a good material to be used in pre-prosthetic surgery. LIs inserted into FFB can be considered reliable, although a higher marginal bone loss has to be expected when wider implants and fixed prosthetic restorations are used

Comparison between differential expressed miRNA of osteoblast-like cells cultured with P-15 vs. bio-oss

Bio-Oss is composed of anorganic bovine bone whereas P-15 is an analog of the cell binding domain of collagen. Both are widely used in several bone regeneration procedures in oral surgery. How these biomaterials act on osteoblast activity to promote bone formation is poorly understood. We attempted to get more insight using microRNA microarray techniques to investigate the translation regulation in osteoblasts exposed to P- 15 and Bio-Oss. By using miRNA microarrays containing 329 probe designed -from Human miRNA sequence, we identified in osteoblast-like cells line [MG-63] cultured with Bio-Oss[R] [Geistlich, Wolhusen, Switzerland] and P-15 [Ceramed, Lakewood, CO] several miRNA which expression is significantly modified. There were 4 up-regulated miRNA [i.e. let-7c, mir-27a, mir-125a, mir-30c] and 5 down-regulated miRNA [i.e. mir-23a, mir-320, let-7b, mir-145, mir-128a]. P-15 acts preferentially on homeobox genes whereas Bio-Oss activates preferentially extravellular matrix componets, cytokines and hormones. P-15 and Bio-Oss enhance the translation process of different BMPs: BMP1 and BMP4 the first material and BMP 3 and 11 the second one