complete dentures Preclinical **Patient Evaluation** & Primary Impression     Complete Denture Overview **Treatment Schedule** | Visit | Operator | Procedure | |---|---|---| | Visit 1 | Clinician<br>**Laboratory** | **Patient evaluation** & primary impressions<br>Diagnostic casts & special trays | | Visit 2 | Clinician<br>**Laboratory** | Secondary impressions<br>Bead & box, master casts, base & rims | | Visit 3 | Clinician<br>**Laboratory** | Contour rims, OVD, MMR, shade & mould selection<br>Articulation & tooth setting | | Visit 4 | Clinician<br>**Laboratory** | Wax try-in<br>Finalisation & processing | | Visit 5 | Clinician | Assessment & issue<br>Instructions for care | | Visit 6 | Clinician | Post operative review, post insertion instructions | **Patient Evaluation** **Medical History** → General health → Current medications → Neuromuscular system (Stroke, Parkinson’s) → Nutritional disturbances → Blood dyscrasias → Allergies Dental History Extra-oral Examination Intra-oral Examination Radiographic Examination Review of Existing Prostheses **Patient Evaluation** Medical History **Dental History** Extra-oral Examination Intra-oral Examination Radiographic Examination Review of Existing Prostheses → How many years edentulous → Reasons for tooth loss → Difficult extractions? (possible retained roots) → Age of dentures → Repairs, relines, cracks or additions **Patient Evaluation** Medical History Dental History **Extra-oral Examination** Intra-oral Examination Radiographic Examination Review of Existing Prostheses Facial morphology Palpation of major lymph nodes Aesthetic evaluation Development of facial musculature Skeletal base relationship Lips (length, mobility, aesthetics) TMJ activity **Patient Evaluation** Medical History Dental History Extra-oral Examination **Intra-oral Examination** Radiographic Examination Review of Existing Prostheses Alveolar ridges Oral Mucosa Denture bearing area Posterior palatal seal Palate shape Sulcus depth Frena attachments (level, size & activity) Inter-ridge space Ridge relation Saliva (type, quantity) Tongue (size, activity, pathology) Abnormalities (denture hyperplasia, tori) Intra-oral Examination **Alveolar Ridges** 1. BC = AB = CA = Normal 2. BC > AB = CA = Low 3. BC < AB = CA = High  Intra-oral Examination **Oral Mucosa** Systemic factors Old age Diabetes mellitus Nutritional deficiency Malignancy Immune defects Medications: Corticosteroids Anti-cancer drugs Local factors Dentures: Trauma 24/7 usage Poor hygiene Xerostomia: Sjogren’s syndrome Irradiation Drug therapy  Two labeled intra-oral images showing denture bearing anatomical landmarks.   Intra-oral Examination Posterior Palatal Seal **Posterior limit:** The distal demarcation of the movable and non-movable tissues of the soft palate. (vibrating line) – usually ~ 2mm anterior to Fovea Palatini **Anterior limit:** The junction of the hard and soft palates on which pressure, within physiologic limits, can be placed **Lateral extension:** Hamular notch  Intra-oral Examination Palate Shape **U-Shape** Ideal retention and stability   Intra-oral Examination Palate Shape **V-Shape** Less retention   Intra-oral Examination Palate Shape **Flat** Reduced resistance to lateral forces   Intra-oral Examination Sulcus Depth Shallow maxillary **buccal** sulci  **Intra-oral Examination** **Frena Attachments** Labial frenum Superior incisive muscles   **Intra-oral Examination** **Inter-Ridge Space**  Intra-oral photograph showing ridge relationship.  Photograph of tongue showing size and position during intra-oral examination.  Intra-oral Examination **Abnormalities** Soft Tissue Disorders Flabby maxillary ridge Flabby maxillary ridge Flabby mandibular ridge Management of excessive soft tissue • small excess – relieve area in impression • large excess -- may require surgery    Intra-oral Examination **Abnormalities** Soft Tissue Disorders Posterior palatal seal hyperplasia Posterior maxillary ulceration Palatal hyperplasia    Intra-oral Examination **Abnormalities** Hard Tissue Disorders Palatal torus Mandibular tori   **Patient Evaluation** Medical History Dental History Extra-oral Examination Intra-oral Examination **Radiographic Examination** {OPG +/- PA} Unerupted teeth Retained roots Bone quantity and quality TMJ Review of Existing Prostheses Radiographic Examination Pretreatment digital panoramic radiographs revealed **very few abnormalities that influenced the treatment** of patients requiring complete removable dental prostheses reinforcing current guidelines that recommend against radiographic screening of patients who seek new complete removable dental prostheses, unless indicated by a careful history-taking. Kratz et al. 2017     **Patient Evaluation** Medical History Dental History Extra-oral Examination Intra-oral Examination Radiographic Examination **Review of Existing Prostheses** Occlusal vertical dimension Stability & retention Extension Occlusion/articulation Phonetics Wear Review of Existing Prostheses **Existing dentures** - Occlusal vertical dimension - Stability & retention - Peripheral extension - Occlusion / articulation - Aesthetics - Phonetics - Wear **Talk to the patient!** - Identify chief complaints - Difficulties with adjusting to dentures - How many years with dentures - Beware of patient that presents with a collection of **"unsatisfactory"** dentures   **Complete Denture Overview** **Treatment Schedule** | Visit | Operator | Procedure | |----------|----------------------|-----------------------------------------------------| | Visit 1 | Clinician <br> **Laboratory** | Patient evaluation **& primary impressions** <br> Diagnostic casts & special trays | | Visit 2 | Clinician <br> **Laboratory** | Secondary impressions <br> Bead & box, master casts, base & rims | | Visit 3 | Clinician <br> **Laboratory** | Contour rims, OVD, MMR, shade & mould selection <br> Articulation & tooth setting | | Visit 4 | Clinician <br> **Laboratory** | Wax try-in <br> Finalisation & processing | | Visit 5 | Clinician | Assessment & issue <br> Instructions for care | | Visit 6 | Clinician | Post operative review, post insertion instructions | **Primary Impressions** Impression Materials **Thermoplastic** Modelling compound **Chemical Reaction** Alginate Impression Material Plaster of Paris **Digital** Intra-oral scan Extra-oral scan of impression or cast Impression Materials Thermoplastic Modelling compound Chemical Reaction Alginate Impression Material Plaster of Paris Digital Intra-oral scan Extra-oral scan of impression or cast Impression Materials **Thermoplastic** Modelling Compound 55<sup>0</sup> -60<sup>0</sup>       Impression Materials Chemical Reaction Alginate Impression Material **Properties** Elastic Hydrophilic Irreversible set Composition – by weight Potassium alginate **12%** Diatomaceous earth **70%** Calcium sulphate **12%** Trisodium phosphate **2%**  Alginate Impression Material Tray Selection Disposable Trays **Edentulous –with handle** Polytray – with removable handle Mouldable – with handle Current OHCWA stock      **Alginate Impression Material** **Disposable Trays** Tray Modification       Alginate Impression Material **Clinical Manipulation** Measure powder One level scoop to one measure of water Gently tap powder scoop with spatula to sprinkle powder into water Initially stir mixture with a spatula to wet the powder then spatulate vigorously until the mixture is smooth and bubble free    Alginate Impression Material Clinical Manipulation • Do not wet the surface of the material • No movement in mouth during setting • Snap out of mouth following setting • Rinse on removal from mouth • Disinfect by soaking • Pour cast as soon as possible  **Alginate Impression Material** Assessment of Impressions • Correct orientation of tray • Correct border extension • No voids or pressure spots • Uniform thickness of material     Alginate Impression Material **Storage of Impressions** • Set alginate can undergo **imbibition** or **syneresis** if left in a normal environment. **Imbibition** The taking up of fluid by a colloidal system resulting in swelling **Syneresis** The contraction of a gel accompanied by the separating out of liquid • After disinfection cover with damp gauze and place in Ziploc plastic bag. • Pour cast as soon as possible but no sooner than ten minutes following removal from mouth to allow elastic recovery. • Do not place in a refrigerator overnight. Alginate Impression Material Pouring Working Cast - **Gently air-dry impression** - Measure water & powder accurately - Mix stone to creamy consistency either manually or mechanically Hand spatulation Vacuum mixer Vibrate stone into impression Fill impression up to borders. Make stone patty with remainder After initial set of stone invert impression onto patty      **Alginate Impression Material** <b>Working Cast</b> **THE UNIVERSITY OF WESTERN AUSTRALIA** Oral Health Centre **of Western Australia**     Thank You Any questions? Contact me Dr Ian Lander ian.lander@uwa.edu.au