Fluid / moisture control is imperative to making a good impression. Moreover, a good impression requires lateral displacement of the gingiva so the impression material can be deposited on the finish line and also record some of the unprepared tooth located apical to the finish line. The purpose of this presentation is to provide the clinician with valuable insights and techniques that will permit effective fluid control and gingival retraction in preparation for making fixed prosthodontic impressions.

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  • 1. Charles J. Goodacre, DDS, MSD Professor of Restorative Dentistry Loma Linda University School of Dentistry This program of instruction is protected by copyright ©. No portion of this program of instruction may be reproduced, recorded or transferred by any means electronic, digital, photographic, mechanical etc., or by any information storage or retrieval system, without prior permission. Fluid Control and Tissue Management for Fixed Prosthodontic Impressions
  • 2. Reasons for Fluid Control •  Fluid / moisture control is imperative to make a good impression •  A good impression requires lateral displacement of the gingiva so the impression material can be deposited on the finish line and also record some of the unprepared tooth located apical to the finish line •  The gingiva is moist and may bleed from the displacement, necessitating fluid control •  Fluid / moisture is also needed to prevent saliva from coating the gingiva and prepared tooth and thereby interfering with impression making
  • 3. Types of Fluid Control •  Retraction cord in the sulcus •  Cotton rolls in the vestibules to contain saliva •  Dri-Angles placed on the cheek •  Saliva ejector •  Suction by dental assistant •  Isolite system (suction, light, and tongue displacement)
  • 4. The Purpose of Tissue Retraction is to Displace the Gingiva so: •  The finish line can be evaluated •  The tooth structure apical to the finish line can be examined •  The gingiva is less likely to be traumatized by rotary instruments •  Impression material can record the finish line plus some tooth structure apical to the finish line
  • 5. Gingival Displacement (Retraction) Methods •  Mechanical Cord; Instrument; or Cord & Instrument •  Mechanical-Chemical Cord & Hemostatic agent •  Surgical Electrosurgery; or Laser surgery
  • 6. Mechanical-Chemical-Hand Instrument To Minimize Gingival Trauma While Smoothing A Tooth Preparation
  • 7. ULTRAPAK Displacement Cords by Ultradent Products
  • 8. Retraction Instruments •  Smooth bladed instruments •  Blades with perimeter serrations •  Periodontal probe
  • 9. Smooth-Sided & Serrated Perimeters
  • 10. Curved Instruments Are Available That Can Hold The Tissue Out Of Contact With Rotary Instruments
  • 11. Serrated Instruments Can Lift Cords Out Of The Sulcus Periodontal Probe Can Be Effective When There Is Minimal Sulcus Depth & Tightly Adapted Gingiva Smooth Bladed Instruments Are Comonly Used To Place Gingival Retraction Cord Into The Gingival Sulcus
  • 12. Cords Should Be Moist & Immersed In A Hemostatic Agent
  • 13. Never Pack Dry Cord •  Dry cords adhere to the crevicular epithelium and their removal tears the epithelium and elicits a wound healing reaction Anneroth, Odontol Revy 1969;20:301-310 •  Dry cord is harder to pack into the sulcus, leads to more bleeding upon cord removal and an unaccpetable impression, and makes it more likely that a less than ideal gingival response will follow
  • 14. Preparing Cord For Placement Into The Sulcus •  Cut a segment of cord to the estimated circumference of the tooth plus a little extra •  Form into a circle and hold with cotton pliers •  Immerse into hemostatic agent •  Blot off excess hemostatic agent •  Hold loop of cord over prepared tooth •  Place cord into sulcus with instrument starting on the proximal surface
  • 15. Minimizing Trauma When There Is Thin, Delicate Gingiva Retraction Cord Placement Should Be Started Proximally Where Tissue Is More Easily Displaced
  • 16. Gingival Retraction Techniques Commonly Used By Prosthodontists •  Results from 1,246 survey responses •  98% of prosthodontists use retraction cord •  43% of those using cord routinely use a two cord technique for more than half of their impressions Hansen, J Prosthod 1999;8:163-170
  • 17. Cord Medicament Usage •  81% of prosthodontists soak cords before placing them into sulcus •  55% use aluminum chloride (like Hemodent) •  23% use ferric sulfate / ferric subsulfate (like Astringedent) •  70% use an additional agent after the cord is placed. Ferric sulfate with an infuser / burnisher was the most common additional agent Hansen, J Prosthod 1999;8:163-170
  • 18. ViscoStat® Ultradent Products www.ultradent.com Control Bleeding Using Dento-Infuser Syringe Tip
  • 19. Hemorrhage Control
  • 20. Epinephrine Cords vs. Others •  22 students & 8 faculty could not tell difference (epinephrine vs. aluminum sulfate in a blind study) Jokstad, J Prosthet Dent 1999;81:258-261 •  Epinephrine did not produce superior displacement to Hemodent (AlCl3) Weir, J Prosthet Dent 1984;51:326-329 •  No practical difference between aluminum sulfate, epinephrine, and aluminum chloride Gennaro, J Prosthet Dent 1982;47:384-386
  • 21. My Preferred Technique
  • 22. STEP 1: Cut a segment of a smaller diameter cord to the estimated circumference of the tooth plus a little extra. Form into a circle and hold with cotton pliers
  • 23. I prefer ViscoStat to control bleeding without etching the dentin surface and removing the dentin smear plugs (contains fumed silica to limit acid activity making it kinder to hard and soft tissue) Ultradent Products www.ultradent.com STEP 2: Select a hemostatic agent
  • 24. ViscoStat® Is Very Effective At Controlling Bleeding But It Can Leave A Brown Residue When There Is A Lot Of Bleeding. The Residue Can Be Removed Using A Cotton Pellet Soaked In Hemodent
  • 25. STEP 3: The cords are immersed into the solution in the dappen dish, and then the excess solution blotted on a cotton roll while leaving the cord saturated with the ViscoStat.
  • 26. STEP 4: Pack the smaller diameter cord (#000 black cord) into the gingival sulcus using a smooth-blade cord packing instrument, cut off the excess length, and place it completely into sulcus. The finish line should be visible after the first cord is placed into the sulcus
  • 27. STEP 5: Pack the second larger diameter cord (#0 purple cord) into the sulcus so there is excess length and the ends are visible for easy removal at the time the impression material is syringed around the tooth
  • 28. STEP 6: Use compressed air to dry the tooth but do not dessicate the gingiva and cord as that will cause fusion of the cord to the gingiva and instantaneous bleeding when the cord is removed Remove the 2nd cord (leaving the 1st cord to control moisture and hemorrhage) and syringe impression material directly behind the exiting second cord to minimize the opportunity for moisture or hemorrhage to reach the finish line before the impression material
  • 29. Syringe Tip Access To Interproximal Finish Line
  • 30. Thank You For Your Kind Attention Charles J. Goodacre, DDS, MSD Professor of Restorative Dentistry Loma Linda University School of Dentistry
  • 31. v Visit ffofr.org for hundreds of additional lectures on Complete Dentures, Implant Dentistry, Removable Partial Dentures, Esthetic Dentistry and Maxillofacial Prosthetics. v The lectures are free. v Our objective is to create the best and most comprehensive online programs of instruction in Prosthodontics