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Invasive cervical resorption is a relatively un common form of external root resorption which has been a source of interest and academic debate by clinicians and researches for over a century. Tooth resorption is a condition associated with either a physiological or a pathological process resulting in loss of dentin, cementum or bone (1,2). This condition has been variously labeled, but because of its invasive nature of the term seems more appropriate to invasive cervical resorption. Although the etiology of this conditions remains obscure, knowledge of potential predisposing factors is important in assessing patients at risk. It is seen in most cases a late complication of traumatic injuries of teeth, but it may also occur after orthodontic movement, tooth bleaching, scaling, chronic inflammation of the pulp and periodontal tissue, root planing and a wide variety of traumatic conditions. The diagnosis of resorption into internal and external resorption is usually based on clinico-radiographic finding, internal resorption is comparatively more destructive and results in loss of tooth structure without the deposition of any hard tissue. It is most commonly found in the cervical region, and clinically presents asymptomatically. Usually, the coronal pulp is necrotic, the resorptive defect creates a clinically obvious pinkish color (“pink spot”) in the crown. The same resorptive process can occur in other tooth locations: in erupting teeth in may arise trough an enamel defect in the tooth crown and may be termed invasive coronal resorption, while a more apical source may be termed invasive radicular resorption. In root canal that leads to resorption of the aetiology is not known for which it was defined by the term idiopathic. Radiographically the lesion presents as a circumscribed in continuous expansion. Invasive cervical resorption has and continues to be misdiagnosed as a form of internal resorption, a misunderstanding that could possibly be attributed to the descriptions of internal resorption by Gaskill in 1984 and by Mummery in 1920 which included teeth showing “pink spot”. Currently, the etiology of invasive cervical resorption is poorly understood and this may explain some of the diversity in terminology. A basic question to be answered by researches is whether this process is purely inflammatory in nature, more probably activated by sulcural microorganisms, o alternatively a type of benign proliferative fibrovascular or fibro-osseus disorder in which microorganisms play a secondary role as an invading pathogen as demonstrated by studies of recently acquired. The classification in the diagram below shows the types of dental resorption in the regions.

Low-level laser therapy (LLLT) has been reported to enhance wound healing. Activation of fibroblasts has a potential for early wound healing in oral cavity. The aim of this study was to determine adequate energy doses using specific parameters of LLLT to produce biostimulatory effects on human fibroblasts culture. Materials and Method: cells were seeded on multiwell plates and exposed to a 980 nm diode laser with energy doses of 0,5, 1, 2, 4, 5, 7, 17, 50 J/cm2. Cell metabolism was evaluate by using 3-(4, 5-dimethylithiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT). Cell proliferation was measured by sulforhodamine B (SRB) assay. Data were analyzed by variance test with statistical significance of 5% . Results: irradiation of the fibroblasts with 2, 4 and 5 J/cm2 resulted in significant increase in cell metabolism compared with non-irradiated group (P˂ 0,05), 2 J/cm2 was found to be an optimal energy density. Cell proliferation was significantly stimulated at 2 J/cm2 . Conclusions: LLLT stimulates cell metabolism and proliferation of fibroblasts in vitro.

SURGICAL-RADIOGRAPHIC PART:The aim of the present retrospective chart review was to determine the relationship between nonvascularized osseous graft remodeling and the three-dimensional (3D) features of grafts and recipient sites, the anatomical recipient regions and different graft procedures. 18 iliac crest were onlay-positioned in the mandible or maxilla or used in sinus lift procedures. CT scans, taken before implant positioning and after 1 year, revealed a mean volume resorption of 40%. For iliac crest grafts, the average resorption was 36% when the onlay was positioned in the anterior maxilla, 77% when it was positioned in the posterior mandible and 17% in sinus lift procedures. GENIC PART: This part of the study aims to identify and rank genes involved in osseous augmentation or bone remodeling to obtain groups with more numerous predicted associations called the leader gene clusters. An iterative search (consisting of a consecutive expansion-filtering loop) was performed for which only genes involved in a specific process were identified. For each gene, predicted associations with all other involved genes were obtained from a Web-available database (Search Tool for the Retrieval of Interacting Genes/Proteins) and the weighted number of links (WNL), given by the sum of only high-confidence predicted associations (results with a score > or =0.9), allowing gene ranking. A total of 161 genes potentially involved in bone-volume augmentation and 128 genes connected with the bone-remodeling phenomenon were identified.

The aim of our study was to evaluate the properties of the laser-modified titanium surface, that are its skills of promoting a faster differentiation of human Mesenchymal Stem Cells (hMSCs) into osteoblasts and a more stable connection between differentiated cells and titanium comparing to the machined and the sand-blasted surfaces. Furthermore, we wanted to evaluate if titanium alone was a sufficient factor able to induce the differentiation towards the osteogenic lineage. Materials and methods: we harvested stem cells from an individual (after his consensus) and cultivated them into dishes with titanium disks presenting three different surfaces: machined (M), sand-blasted (S) and laser-modified (L). In the test group cells were cultivated in an osteogenic medium, while in the control group cells were seeded in a standard DMEM. Evaluations of the degree of differentiation were made with Alizarin coloration after 28, 38, 42, 49, 56 and 63 days of induction. Results: no signs of differentiation were evident in the control group, while in the test group there was a statistically significant differentiation evident since the fourth week. Laser-modified and sand-blasted surfaces showed similar values, greater than the machined surface. Discussion: the differentiation reached its peak on the sixth week for the laser-modified surface, and on the seventh week for the other two surfaces. After the peak, the differentiation had a slow decrease for the laser-modified surface and a rapid decrease for the other two. Conclusions: titanium alone can’t be considered a sufficient factor able to induce differentiation of human Mesenchymal Stem Cells into osteoblasts. Moreover, laser-modified induces a faster differentiation of stem cells and a more stable connection between osteoblasts and titanium.