a b s t r a c tBackground: Amon Q2 g various dental materials and their successful restorative uses, titanium provides an excellent example of integrating science and technology involving multiple disciplines of dentistry including biomaterials, prosthodontics and surgical sciences. Titanium and its alloys have emerged as a material of choice for dental implants fulfilling all requirements biologically, chemically and mechanically. Several excellent reviews have discussed the properties of titanium and its surface characteristics that render it biocompatible. However, in most patients, titanium implants are used alongside several other metals. Presence of different metals in the same oral environment can alter the properties of titanium. Other influencing factors include intra-oral pH, salivary content, and effect of fluorides. Highlight: This review discusses the effect of the above-mentioned conditions on the properties of titanium and its alloys. An extensive literature search encompassing the properties of titanium in an altered oral environment and its interaction with other restorative materials is presented. Specific conditions that could cause titanium to corrode, specifically due to interaction with other dental materials used in oral rehabilitation, as well as methods that can be employed for passivation of titanium are discussed. Conclusion: This review presents an overview of the properties of titanium that are vital for its use in implant dentistry. From a restorative perspective, interaction between implant restoration metals, intraoral fluorides and pH may cause titanium to corrode. Therefore, in order to avoid the resulting deleterious effects, an understanding of these interactions is important for long-term prognosis of implant restorations.

Background:Previous in vitro studies indicated that dentin matrix protein 1 (DMP1) might regulate dentin sialophosphoprotein (DSPP) expression in odontoblasts. Results: Transgenic expression of DSPP rescued the tooth defects of Dmp1 knockout mice. Conclusion: DSPP is a downstream effector molecule of DMP1 in dentinogenesis. Significance: This study has identified the in vivo functional relationship of DMP1 and DSPP in dentinogenesis.

Background:In dentin and bone, dentin sialophosphoprotein (DSPP) is processed into the NH 2 -terminal and COOHterminal fragments. Results: The blocking of DSPP processing leads to hypomineralization defects in dentin, similar to those of Dspp-deficient mice. Conclusion:The proteolytic processing of DSPP is an activation step essential to dentinogenesis. Significance: This study represents major progress in understanding how DSPP functions in dentinogenesis.

Background: FAM20C is highly expressed in odontoblasts, ameloblasts, and cementoblasts. Results: Fam20C knock-out mice displayed severe defects in dentin, enamel, and cementum, along with remarkable downregulation of differentiation markers of odontoblasts and ameloblasts. Conclusion: FAM20C is essential to the differentiation of tooth-formative cells and the formation of dentin, enamel, and cementum. Significance: These data provide strong evidence that FAM20C plays a critical role in tooth formation.

Background and Objective Dentin sialophosphoprotein (DSPP) and its cleaved products, dentin phosphoprotein (DPP) and dentin sialoprotein (DSP), play important roles in biomineralization. Recently, we observed that DSPP is highly expressed in the alveolar bone and cementum, indicating that this molecule may play an important role in the formation and maintenance of a healthy periodontium, and its deletion may cause increased susceptibility to periodontal diseases. The objective of this investigation was to study the effects of Dspp ablation on periodontal tissues by analyzing Dspp null mice. Methods Newborn to 6-month-old Dspp null mice were examined, and the 3-month and 6-month-old Dspp null mice were characterized in detail using X-ray radiography, histology and scanning electron microscopy (backscattered as well as resin-infiltrating). Wild-type mice of the same age groups served as the normal controls. Results The Dspp null mice showed a significant loss of alveolar bone and cementum, particularly in the furcation and the interproximal regions of the molars. The alveolar bone appeared more porous while the quantity of cementum was reduced in the apical region. The canalicular systems and osteocytes in the alveolar bone were abnormal, with reduced numbers of canaliculi and an altered osteocyte morphology. The loss of alveolar bone and cementum along with the detachment of the periodontal ligaments (PDL) led to the apical migration of the epithelial attachment and the formation of periodontal pockets. Conclusion Inactivation of DSPP leads to the loss of the alveolar bone and cementum and increased susceptibility to bacterial infections in the PDL of Dspp null mice. The fact that the loss of DSPP results in periodontal diseases indicates that this molecule plays a vital role in maintaining the health of the periodontium.