Study On The Implant Esthetic Abutment Of The Maxillary Premolar

Over the past several years,dental esthetics has been an important issue in implant dentistry. At major conferences it is common to see lectures addressing various techniques for achieving esthetic implant restoration. In esthetically demanding anterior regions of maxillary premolar, an successful implant-supported crown is not only defined by established osseointegration, but also by the presence of natural soft tissue and crown contours. From an esthetic point of view, one crucial factor that influences the individual appears of restoration is the emergence profile. As the cross-section of implant shoulder and natural maxillary premolar at the gingival level differ, establishing the desired contours by means of definitive crown requires that anatomic gingival emergence profile should be established in advance.Conventional method to establish desired anatomic gingival emergence profile is modality of acrylic resin provisional restoration. But, this method are always complicated in manipulation and time consuming to both clinician and technician. Patient should return several times for modification of the shape of provisional crown in order to acquire ideal scalloped soft tissue emergence profile around implant abutment.The purpose of this study is to develop an alternative esthetic gingival conditioning abutment that can be used in esthetic maxillary premolar zone. This type of esthetic abutment combines the function of gingival esthetic conditioning and transmucosal healing. In this study, an integrated manufacturing system for producing esthetic abutment using laser surface scanning/digitizing, computer-aided design (CAD), computer-aided manufacturing (CAM), and rapid prototype (RP) technologies is introduced. Meanwhile, the advantages of the esthetic abutment over traditional healing abutment and modality of provisional crown conditioning restoration are discussed.1,Data acquisition-- Natural teeth measurement and statistical analysisThe extracted maxillary premolars were used in this study. Measurements were carried out to calculate the curvature of CEJ. The data were transferred to a spreadsheet program for mathematic treatment, statistical analysis (SPSS13.0) was performed to calculate the mean values of CEJ curvature in height (c), cervical thickness dimensions (v-p line). Statistical values incorporate means, standard deviations, 25% quartiles, 50% quartiles, 75%quartiles.2,Surface laser scanning and to assess the reliability of dimensional measurement of standard dental modelsLaser scanning were undertaken on standard teeth models. These dental models made of hard acrylic were about twice as large as natural teeth .The surface was then represented by a cloud of up to 10,000 points with 3D coordinates. Digital surfaces images gained by laser scanning can be rotated and adjusted in PC screen with manipulating surfacer12.0 software. The imaging-processing program was used to trace the contour of CEJ and measure its vestibule-palatal cervical dimensions. The same values in actual dental models were measured by the sliding caliper. A comparison was made between the digitizing graph with natural maxillary premolar. Results show that there was generally little difference between digitizing graph with natural maxillary premolar.3,Computer design and rapid prototype(RP)The files that represent a 3-D model in point-cloud way were imported and processed by surfacer 12.0 software (Imagesurfacer, USA). The completed CAD models of the molds were converted into Stereolithography (STL) file format for rapid prototype (RP) fabrication. With RP-fabricated mold, a vacuum casting technique was employed to cast the actual titanium esthetic abutments of maxillary premolar.ConclusionsIn summary, use of a computer-aided design, computer-aided manufacturing and rapid prototype, custom-design titanium abutment of maxillary premolar overcome this challenge since such an abutment can be designed to follow precisely the gingival scallop. The greatest advantage that the implant esthetic abutment of maxillary premolar design offers is clinical versatility, the proven biocompatibility and simplified clinical manipulation. It can enable the clinician to achieve optimal esthetics in the esthetic zone combined with a simple and time-efficient fabrication and delivery.