Alginate Impressions on a Patient DA 122 Dental Materials

Alginate Powder & Scoop Alginate Tray Set-up Water Measuring Cup Spatula Alginate Powder & Scoop Mixing Bowl Mandibular Tray Maxillary Tray

Armamentarium

Alginate Trays

Adding wax periphery

Set-up for Alginate Alginate bowls Alginate spatulas Fresh, room temperature water Measuring scoops / water vial Impression trays (metal-perforated, rimlock) or disposable-perforated Cup of mouthwash and paper towel Damp paper towel Labeled ziplock bag

Measure alginate and water Maxillary arch: 3 scoops alginate 3 lines water (room temperature) Mandibular arch: 2 scoops alginate 2 lines water Water is measured and dispensed in the plastic water measurer that comes with the materials Excess water will weaken the final set

Taking the Impression Try tray in patient’s mouth Mix material Remove excess material Place gently in patient’s mouth Hold until set Copyright © 2006 Thomson Delmar Learning. ALL RIGHTS RESERVED.

Try in the tray Try the tray in the patient’s mouth BEFORE mixing any alginate Be sure the tray fits properly It’s best to do mandibular impressions first Less likely to set off gag reflex!

Mixing Alginate

Mixing Alginate Put measured powder into rubber bowl Incorporate water gently until completely moistened Hold bowl in left hand and spatulate with right hand Use a wiping motion Spatulate mix into creamy, homogeneous consistency Alginate should be mixed for 60 seconds Increasing the water temperature will shorten the mixing time!

Mixing Alginate Undermixing: Mixture will be grainy Model will have poor detail

Loading the Alginate Tray

Loading the tray A useful method is to start at the posterior and push the mix anteriorly by adding more and more to the posterior

Alginate Impressions – Taking the Impression Removal of Small Amount from Palate

Alginate Impressions – Taking the Impression Insertion

Alginate Impressions – Taking the Impression Holding Tray in Position

Removing the Impression Ensure material is set Carefully rock tray back and forth Keep fingers steady to protect teeth Give patient wet paper towel for face Check impression for landmarks Rinse impression Disinfect impression Copyright © 2006 Thomson Delmar Learning. ALL RIGHTS RESERVED.

Alginate Impressions – Removing the Impression Breaking the Suction-like Seal

Alginate Impressions – Removing the Impression Position of Fingers Protecting Opposing Arch

Examine the impression: Copyright © 2006 Thomson Delmar Learning. ALL RIGHTS RESERVED.

Evaluate your alginate impression Smooth surface? Rounded periphery? Centered in tray? ¼ inch depth in tray? No oral cavity debris? No tray showing? No torn or thin places? Good detail? Anatomy Distals of posterior molars All sides of teeth visible Retromolar pads/ maxillary tuberosity Muscle attachment Abnormalities? (tori, etc.)

Alginate Impressions – Rinsing of Impression with Water

Alginate Impressions: Spray with Disinfectant

Alginate Impressions: Wrapping Alginate with damp paper towel

Ziplock bag labeled with patient’s full name Alginate Impressions – Disinfecting the impression Ziplock bag labeled with patient’s full name