PMID- 30881396
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20220408
IS  - 1682-024X (Print)
IS  - 1681-715X (Electronic)
IS  - 1681-715X (Linking)
VI  - 35
IP  - 1
DP  - 2019 Jan-Feb
TI  - Marginal accuracy of provisional crowns using three material systems and two 
      techniques: A scanning electron microscope study.
PG  - 55-60
LID - 10.12669/pjms.35.1.5 [doi]
AB  - OBJECTIVE: The most important desideratum of a provisional crown is an adequate 
      marginal fit that is essential for maintaining optimal periodontal health, 
      reducing the sensitivity of freshly prepared dentin and protection of the pulp. 
      The purpose of this in vitro study was to compare the vertical marginal accuracy 
      of provisional crown materials using three different material systems (chemically 
      activated PMMA powder-liquid system, light activated UDMA single paste system, 
      and chemically activated Bis-GMA two paste auto mix system) and two different 
      techniques (direct and indirect). METHODS: Two customized stainless steel dies, 
      simulating prepared and unprepared tooth were used to fabricate 40 provisional 
      crowns. Additional silicone elastomeric impression and a vacuum-formed 
      polypropylene sheet were used as a matrix. Ten crowns, each of the three material 
      systems used in the study (n = 10 x 3) were fabricated using the direct technique 
      and ten crowns from chemically activated PMMA powder-liquid system (n = 10 x 1) 
      using an indirect technique. Scanning electron microscope (SEM) was used to 
      measure vertical marginal discrepancies at x100 magnification. The results were 
      analyzed using descriptive statistics and comparisons between various groups were 
      made using one way analysis of variance (ANOVA) after checking the normality of 
      data using Shapiro Wilk's Test. Post Hoc Tukey HSD Test was used to determine the 
      statistical difference between the means of independent group pairs. RESULTS: The 
      mean marginal discrepancies of Bis-GMA composite resin, UDMA composite resin, and 
      PMMA acrylic resin using direct technique were 67.15 microm, 71.01 microm, and 84.56 microm 
      respectively. PMMA acrylic resin showed a mean marginal discrepancy of 103.03 microm 
      using the indirect technique. CONCLUSION: This study has shown that provisional 
      crowns fabricated with Bis-GMA composite resin material (two paste auto mix 
      system) registered the best marginal accuracy. Provisional crowns fabricated with 
      indirect technique recorded less marginal opening than with direct technique.
FAU - Naqash, Talib Amin
AU  - Naqash TA
AD  - Dr. Talib Amin Naqash, MDS. Assistant Professor, Department of Prosthetic 
      Dentistry, College of Dentistry, King Khalid University, Abha, Saudi Arabia.
FAU - Alfarsi, Mohammed
AU  - Alfarsi M
AD  - Dr. Mohammed Alfarsi, PhD. Assistant Professor, Department of Prosthetic 
      Dentistry, College of Dentistry, King Khalid University, Abha, Saudi Arabia.
FAU - Hussain, Muhammad Waqar
AU  - Hussain MW
AD  - Dr. Muhammad Waqar Hussain, MDS. Assistant Professor, Department of Prosthetic 
      Dentistry, College of Dentistry, King Khalid University, Abha, Saudi Arabia.
LA  - eng
PT  - Journal Article
PL  - Pakistan
TA  - Pak J Med Sci
JT  - Pakistan journal of medical sciences
JID - 100913117
PMC - PMC6408644
OTO - NOTNLM
OT  - Bis-phenol A glycidyl methacrylate (Bis-GMA)
OT  - Polymethyl methacrylate (PMMA)
OT  - Scanning electron microscope (SEM)
OT  - Stainless steel die
OT  - Urethane dimethylacrylate (UDMA)
COIS- Conflicts of Interest: None.
EDAT- 2019/03/19 06:00
MHDA- 2019/03/19 06:01
PMCR- 2019/01/01
CRDT- 2019/03/19 06:00
PHST- 2019/03/19 06:00 [entrez]
PHST- 2019/03/19 06:00 [pubmed]
PHST- 2019/03/19 06:01 [medline]
PHST- 2019/01/01 00:00 [pmc-release]
AID - PJMS-35-55 [pii]
AID - 10.12669/pjms.35.1.5 [doi]
PST - ppublish
SO  - Pak J Med Sci. 2019 Jan-Feb;35(1):55-60. doi: 10.12669/pjms.35.1.5.