Key Points
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An overview of impression materials
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A rationale is put forward for the choice of elastomeric materials
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Solutions are provided to common problems encountered by the clinician in producing good, accurate impressions
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An emphasis on the need for feedback between the laboratory and the dentist
Key Points
Crowns and extra-coronal restorations:
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1
Changing patterns and the need for quality
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2
Materials considerations
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3
Pre-operative assessment
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4
Endodontic considerations
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5
Jaw registration and articulator selection
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6
Aesthetic control
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7
Cores for teeth with vital pulps
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8
Preparations for full veneer crowns
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9
Provisional restorations
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10
Impression materials and technique
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11
Try-in and cementation of crowns
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12
Porcelain veneers
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13
Resin bonded metal restorations
Abstract
Well-fitting indirect restorations can only be made if there are accurate models of the oral tissues available, made from high quality impressions. Waiting for an impression to set may be more stressful for the dentist than the patient. Should the impression need to be repeated there is the embarrassment of having to explain this to the patient, the cost implications of material and time wasted and the aggravation of running late for the next appointment. Yet, if a 'Nelsonian' eye is turned to a defective impression we can only expect a substandard restoration in return.
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References
Sears AW . Hydrocolloid impression technique for inlays and fixed bridges. Dent Digest 1937; 43: 230–234.
Brown D . An update on elastomeric impression materials. Br Dent J 1981; 150: 35–40.
Heisler WH, Tjan AHL . Accuracy and bond strength of reversible with irreversible hydrocolloid impression systems: a comparative study. J Prosthet Dent 1992; 68: 578–584.
Appleby DC, Parneijer CH, Boffa J . The combined reversible hydrocolloid/ irreversible hydrocolloid impression system. J Prosthet Dent 1980; 44: 27–35.
Lin C, Zeiber GJ . Accuracy of impression materials for complete arch fixed partial dentures. J Prosthet Dent 1988; 59: 288–291.
Craig RG Restorative Dental Materials. 10 th ed pp281–332 London: Mosby 1997.
Pratten DH, Craig RG . Wettability of a hydrophilic addition silicone impression material. J Prosthet Dent 1989; 61: 197–202.
Vassilakos N, Fernandes CP, Nilner K . Effect of plasma treatment on the wettability of elastomeric impression materials. J Prosthet Dent 1993; 70: 165–171.
Millar BJ, Dunne SM, Robinson PB . The effect of a surface wetting agent on void formation in impressions. J Prosthet Dent 1997; 77: 54–56.
Ozden N, Ayhan H, Erkut S, Can G, Piskin E . Coating of silicone-based impression materials in a glow-discharge system by acrylic acid plasma. Dent Mat 1997; 13: 174–178.
Boening KW, Walter MH, Schuette U . Clinical significance of surface activation of silicone impression materials. J Dent 1998; 26: 447–452.
Wassell RW, Ibbetson RJ . The accuracy of polyvinylsiloxane impressions made with standard and reinforced stock trays. J Prosthet Dent 1991; 65: 748–757.
Abuasi H Accuracy of polyvinyl siloxane impressions [PhD]. University of Newcastle upon Tyne 1993.
Abuasi HA, Wassell RW . Comparison of a range of addition silicone putty-wash impression materials used in the one-stage technique. Eur J Prosthodont Restor Dent 1994; 65: 748–757.
Carrotte PV, Johnson A, Winstanley RB . The influence of the impression tray on the accuracy of impressions for crown and bridgework. Br Dent J 1998; 185: 580–585.
Ray KC, Fuller ML . Isolation of Mycobacterium from dental impression material. J Prosthet Dent 1963; 13: 390–396.
Leung RL, Schonfeld SE . Gypsum casts as a potential source of microbial cross-contamination. J Prosthet Dent 1983; 49: 210–211.
Powell GL, Runnells RD, Saxon BA, Whisenant BK . The presence and identification of organisms transmitted to dental laboratories. J Prosthet Dent 1990; 64: 235–237.
Blair FM, Wassell RW . A survey of the methods of disinfection of dental impressions used in dental hopitals in the United Kingdom. Br Dent J 1996; 180: 369–375.
Watkinson AC . Disinfection of impressions in UK dental schools. Br Dent J 1988; 164: 22–23.
BDA. Advice sheet A12: Infection Control in Dentistry. pp12 British Dental Association Advisory Service 1996.
Shillingburg HT, Hobo S, Whitsett LD, Jacobi R, Brackett SE Fundamentals of fixed prosthodontics. 3rd ed pp257–279 Chicago: Quintessence 1997.
Carrotte PV, Winstanley RV, Green JA . A study of the quality of impressions for anterior crowns received at a commercial laboratory. Br Dent J 1993; 174: 235–240.
Winstanley RB, Carrotte PV, Johnson A . The quality of impressions for crowns and bridges received at commercial dental laboratories. Br Dent J 1997; 183: 209–213.
Cloyd S, Puri S . Using the double cord packing technique of tissue retraction for making crown impressions. Dent Today 1999; 18: 54–59.
Ingber FJS, Rose LF, Coslet JG . The 'Biologic Width' - A concept in periodontics and restorative dentistry. Alpha-Omegan 1977; 10: 62–65.
Brägger U, Lauchenauer D, Lang NP . Surgical lengthening of the clinical crown. J Clin Periodont 1992; 19: 58–63.
Chong YH, Soh G, Lim KC, Teo CS . Porosities in five automixed addition silicone elastomers. Operative Dent 1991; 16: 96–100.
Noonan JE, Goldfogel MH, Lambert RL . Inhibited set of the surface of addition silicones in contact with rubber dam. Operative Dent 1985; 10: 46–48.
Kahn R, Donovan T, Chee W . Interaction of latex gloves and polyvinylsiloxane impression materials: a screening survey. Int J Prosthodont 1989; 2: 342–346.
Baumann MA . The influence of dental gloves on the setting of impression materials. Br Dent J 1995; 179: 130–135.
de CamargoLM, Chee WWL, Donovan TE . Inhibition of polymerization of polyvinyl siloxanes by medicaments used on gingival retraction cords. J Prosthet Dent 1993; 70: 114–117.
Bomberg TA, Hatch RA . Correction of defective impression by selective addition of impression material. J Prosthet Dent 1984; 52: 38–40.
MacSween R . Peel bond strengths of five impression material tray adhesives. J Can Dent Assoc 1991; 57: 654–657.
Davis GB, Moser JB, Brinsden GI . The bonding properties of elastomer tray adhesives. J Prosthet Dent 1976; 36: 278–285.
Tjan AH . Comparing effects of tray treatment on the accuracy of dies. J Prosthet Dent 1987; 58: 175–178.
Howat AP, Capp NJ, Barrett NV J A colour atlas of occlusion & malocclusion. pp182 Aylesbury: Wolfe Publishing Ltd 1991.
Pelzner RB, Kempler D, Stark MM, Lum LB, Nicholson RJ, Soelberg KB . Human blood pressure and pulse rate response to r-epinephrine retraction cord. J Prosthet Dent 1978; 39: 287–292.
Weir DJ, Williams BH . Clinical effectiveness of mechanical-chemical tissue displacement methods. J Prosthet Dent 1984; 51: 326–329.
Bowles WH, Tardy SJ, Vahadi A . Evaluation of new gingival retraction agents. J Dent Res 1991; 70: 1447–1449.
deGennaro GG, Landesman HM, Calhoun JE, Martinoff JT . A comparison of gingival inflammation related to retraction cords. J Prosthet Dent 1982; 47: 384–386.
Donovan TE, Gandara BK, Nemetz H . Review and survey of medicaments used with gingival retraction cords. J Prosthet Dent 1985; 53: 525–531.
Shaw DH, Krejci RF, Cohen DM . Retraction cords with aluminium chloride: effect on the gingiva. Operative Dent 1980; 5: 138–141.
Riordan AT, Fosko SW . Electrosurgery and cardiac devices. J Am Acad Dermatol 1997; 37: 250–255.
Ingraham R, Sochat R . Rotary gingival curretage – A technique for tooth preparation and management of the gingival sulcus for impression taking. Int J Periodontol Restorative Dent 1981; 1: 9–33.
Brady WF . Periodontal and restorative considerations in rotary curettage. J Am Dent Assoc 1982; 105: 231–236.
Kamansky FW, Tempel TR, Post AC . Gingival tissue response to rotary gingival curretage. J Prosthet Dent 1984; 52: 380–383.
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Wassell, R., Barker, D. & Walls, A. Crowns and other extra-coronal restorations: Impression materials and technique. Br Dent J 192, 679–690 (2002). https://doi.org/10.1038/sj.bdj.4801456
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