EARN This course was written for dentists, 3 CE dental hygienists, CREDITS and assistants. Identifying and Managing Dental Impression Problems A Peer-Reviewed Publication Written by Gregori M. Kurtzman, DDS, MAGD, FPFA, FACD, FADI, DICOI, DADIA PUBLICATION DATE: APRIL 2018 EXPIRATION DATE: MARCH 2021 SUPPLEMENT TO PENNWELL PUBLICATIONS EARN This educational activity was made possible through 3 CE an unrestricted educational grant by Ultradent. This course was written for dentists, dental CREDITS hygienists and assistants, from novice to skilled. Educational Methods: This course is a self- instructional journal and web activity. Provider Disclosure: PennWell does not have a leadership position or a commercial interest in any products or services discussed or shared in this educational activity nor with the commercial supporter. No manufacturer or third party has had any input into the development of course content. Requirements for Successful Completion: To obtain 3 CE credits for this educational activity you must pay the required fee, review the material, complete the course evaluation and obtain a score of at least 70%. Identifying and Managing CE Planner Disclosure: Heather Hodges, CE Coordinator does not have a leadership or commercial interest with products or services discussed in this Dental Impression Problems educational activity. Heather can be reached at [email protected] EDUCATIONAL OBJECTIVES Educational Disclaimer: Completing a single At the conclusion of this educational activity, participants will be able to: continuing education course does not provide enough information to result in the participant being an 1. Learn how to identify common impression problems expert in the field related to the course topic. It is a 2. Learn how to correct impression problems combination of many educational courses and clinical experience that allows the participant to develop skills 3. Learn how to avoid impression problems and improve impression quality and expertise. 4. Learn what types of impression materials are best suited for particular Image Authenticity Statement: The images in this restorative needs educational activity have not been altered. Scientific Integrity Statement: Information shared in this CE course is developed from clinical research and represents the most current information available ABSTRACT from evidence based dentistry. Fixed restorative dentistry requires an impression of the teeth and area to be restored Known Benefits and Limitations of the Data: The information presented in this educational activity for the laboratory to fabricate the desired restorations. Traditional impressions are is derived from the data and information contained still utilized the majority of the time to capture the needed information. Selection in reference section. The research data is extensive and provides direct benefit to the patient and of the correct viscosity will vary depending on what prosthesis is to be fabricated, improvements in oral health. which tray is being used and whether the preparations are on natural teeth or Registration: The cost of this CE course is $59.00 for implants. Problems can arise during impression taking that can compromise the 3 CE credits. ability of the lab to fabricate the restoration or affect the accuracy and fit of the Cancellation/Refund Policy: Any participant who is not 100% satisfied with this course can request a full finished prosthesis. Identifying impression problems is part of the process, but how refund by contacting PennWell in writing. to manage these to improve the quality and accuracy of our impressions is critical to fixed prosthetics. PennWell designates this activity for 3 continuing educational credits. Dental Board of California: Provider 4527, course registration number CA#03-4527-15259 “This course meets the Dental Board of California’s requirements for 3 units of continuing education.” Go Green, Go Online to take your course The PennWell Corporation is designated as an Approved PACE Program Provider by the www.DentalAcademyofCE.com Academy of General Dentistry. The formal continuing dental education programs of this QUICK ACCESS CODE 15259 program provider are accepted by the AGD for Fellowship, Mastership and membership maintenance credit. Approval does not imply acceptance by a state or provincial board of dentistry or AGD endorsement. The current term of approval extends from (11/1/2015) to (10/31/2019) Provider ID# 320452. DENTAL ACADEMY OF CONTINUING EDUCATION INTRODUCTION Impression fabrication is a critical and technique-sensitive step in the Figure 2 fabrication of fixed prosthetics. It can also be a frustrating stage during treatment, both to the clinician and laboratory technician. Potential complications need to be identified and corrected prior to sending the impression to the lab for fabrication of the prosthetics. This article will address some common difficulties, what factors may cause impression errors, and present methods to correct and avoid complications related to impression capture. INADEQUATE MARGINAL DETAIL INTERNAL BUBBLES The primary complaint laboratory technicians voice with the impressions Vinyl polysiloxane (VPS) is the most widely used of impression materi- they receive daily is inadequate marginal detail and the majority of im- als available. These materials were introduced over 30 years ago and pressions they receive have issues. Marginal detail is the most critical initially were hydrophobic (repealed by water)2 in nature. Manufacturers aspect of the impression as it indicates where the restoration will termi- have improved the chemistry of these impression material to make nate on the tooth. Failure to capture the true details of the margin of the them more hydrophillic (adaptable to wet surfaces). But, moisture preparation will result in open or overhanging margins and inadequate (water, saliva, blood) trapped at internal angles may lead to bubbles in fit of the crown, onlay/inlay or bridge. Voids at the margins are the result the impression. of either insufficient retraction or fluid accumulation that prevented the Internal bubbles occur as a result of either fluid accumulation (when impression material from flowing around the margin. (Figure 1) This can larger and less sharp in definition) or air entrapment (when small and be avoided by using improved retraction methods such as syringeable well defined) (Figure 3). Fluid in the sulcus, be it blood or saliva will hemostatics (e.g. Viscostat and Astringedent, Ultradent, UT; Retrac, interfere with accurate capture of the restorations margins in the im- Centrix, Shelton, CT; Expa-syl1-3, Kerr Sybron, Orange, CA). The traditional approach to achieve sufficient retraction utilizes retraction cords with Figure 3 these syringeable hemostatics such as Ultrapak (Ultradent), Gingi-Plain (Gingi-Pak, Camarillo, CA), Knit-Pak (Premier Dental, Plymouth Meeting, PA), UniBRAID (Dux Dental, Oxnard, CA). Another approach are retrac- tion pastes are placed into the gingival sulcus following preparation and held under pressure with a GingiCap (Centrix Dental, Shelton, CT) or Comprecaps (Coltène/Whaledent, Cuyahoga Falls, OH) creating hemo- stasis and dilation of the sulcus. When adequate retraction is achieved to allow the impression material to capture the prepared restorative margin the lab is able to visualize where the practitioner wants the restoration to terminate on the tooth. (Figure 2). Alternatively, a diode laser (Gemini laser, Ultradent; Picasso, AMD pression. Achieving proper hemostasis solves these issues. Bubbles on LASERS, Indianapolis, IN; Epic, Biolase, Irvine, CA; Precise LTM, CAO the margins of the preparations can negatively affect the fit of the Group, West Jordon, UT) can be used to trough the sulcus both widen- prosthetics. If the bubbles occur on the internal line angles of inlay and ing it to better visualize the prepared margin and hemostasis is also onlay preparations due to fluid accumulation, a substandard fit will be achieved. The laser is kinder to the tissue without the potential for developed. If they occur due to air entrapment, the fit of the restoration recession that was reported with electrosurgery.4 will not be compromised. Bubbles occurring due to fluid accumulation may be large enough to affect the long-term success of the luting agent, which must now fill a wider space. The thicker the luting material the weaker the interface between the restoration and underlying tooth. Figure 1 The prosthetic material may also be thinner than recommended, weakening the restoration and material failure of the crown may result under function. This is more critical when using all-ceramic materials, as they require minimum thicknesses to perform as expected. Use of a wash impression is difficult in a completed impression (2-step impres- sion), as complete seating can be hampered. Should a 2 step approach be considered, removal of impression material interproximally in the www.DentalAcademyOfCE.com 3 DENTAL ACADEMY OF CONTINUING EDUCATION set impression with scissors will prevent the interproximal and between viscosities. The lower the viscosity the more likely it may tear in the material from preventing full reinsertion of the impres- sulcus due to the thinness expressed subgingivally. The deeper the sulcus, the sion intraorally. Additionally, new wash material should thinner the wash material and the higher the potential for it to tear when removed be placed in all the tooth areas on the side of the impres- intraorally. Additionally, removal of the impression