ABSTRACT
The aim of this study is to evaluate and compare the response of bone tissue after osteotomy carried out with either rotating cutters or with piezoelectric terminals.Bioptic samples of bone tissue were taken during operations with rotating burs and piezoelectric terminals to increase bone volume before implantology. Samples first underwent histomorphometric analysis. Subsequently, osteoblastic cells, obtained from different samples, were placed in culture and allowed to proliferate to in vitro evaluate the time to initiate growth and to reach confluence. Finally, a molecular biologic study by reverse transcription polymerase chain reaction was performed to evaluate the expression of typical osteoblastic molecular markers, such as osteoprotegerin and osteopontin.Histomorphometric analysis showed that the width of necrotic line on the osteotomic margins from samples taken using different techniques did not vary significantly. Moreover, the times of initial growth and of confluence in cells from the 2 groups did not show any statistically significant differences. However, a highly significant correlation was revealed between the age of the patient and the initial growth time and the confluence. Similarly, reverse transcription polymerase chain reaction showed that the osteoprotegerin and osteopontin expression levels did not change significantly according to the surgical technique used.In conclusion, osteotomies carried out with either instrument do not seem to substantially influence the vitality of the bone tissue. The variability of the expression levels of typical osteoblastic markers seems to be linked more to other factors than to the surgical technique used.
Subject(s)
Mandible/surgery , Osteoblasts/pathology , Osteotomy/instrumentation , Adolescent , Adult , Age Factors , Aged , Biopsy , Cell Proliferation , Cell Survival/physiology , Cells, Cultured , Child , Electrosurgery/instrumentation , Electrosurgery/methods , Equipment Design , Female , Humans , Male , Mandible/pathology , Middle Aged , Necrosis , Osteopontin/analysis , Osteoprotegerin/analysis , Osteotomy/methods , Reverse Transcriptase Polymerase Chain Reaction , Rotation , Young AdultABSTRACT
INTRODUCTION: The dental pulp undergoes age-related changes that could be ascribed to physiological, defensive, or pathological irritant-induced changes. These changes are regulated by pulp cell activity and by a variety of extracellular matrix (ECM) macromolecules, playing important roles in growth regulation, tissue differentiation and organization, formation of calcified tissue, and defense mechanisms and reactions to inflammatory stimuli. The aim of this research was to better understand the genetic changes that underlie the histological modification of the dental pulp in aging. METHODS: The gene expression profile of the human dental pulp in young and older subjects was compared by RNA microarray analysis that allowed to simultaneously analyze the expression levels of thousands of genes. Data were statistically analyzed by Significance Analysis of Microarrays (SAM) Ingenuity Pathway Analysis (IPA) software. Semiquantitative and real-time reverse-transcriptase polymerase chain reaction analyses were performed to confirm the results. RESULTS: Microarray analysis revealed several differentially expressed genes that were categorized in growth factors, transcription regulators, apoptosis regulators, and genes of the ECM. The comparison analysis showed a high expression level of the biological functions of cell and tissue differentiation, development, and proliferation and of the immune, lymphatic, and hematologic system in young dental pulp, whereas the pathway of apoptosis was highly expressed in older dental pulp. CONCLUSIONS: Expression profile analyses of human dental pulp represent a sensible and useful tool for the study of mechanisms involved in differentiation, growth and aging of human dental pulp in physiological and pathological conditions.