PMID- 35284054
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20220315
IS  - 2005-7806 (Print)
IS  - 2005-7814 (Electronic)
IS  - 2005-7806 (Linking)
VI  - 14
IP  - 1
DP  - 2022 Feb
TI  - The effect of the digital manufacturing technique of cantilevered 
      implant-supported frameworks on abutment screw preload.
PG  - 22-31
LID - 10.4047/jap.2022.14.1.22 [doi]
AB  - PURPOSE: The purpose of this study was to investigate the misfit and screw 
      preload at the implant abutment connection of implant supported fixed dental 
      prosthesis with cantilever (ICFDP) manufactured using different digital 
      manufacturing techniques and to compare the screw preload before and after cyclic 
      loading. MATERIALS AND METHODS: Mandibular jaw model with four intra-foraminal 
      implants was scanned using digital scanner. Stereolithography file was used to 
      design a framework with nonengaging (NE) abutments and 10 mm cantilever distal to 
      one terminal implant. Five frameworks were constructed using combined 
      digital-conventional techniques (CAD-cast), and five frameworks were constructed 
      using three-dimensional printing (3DP). Additional CAD-cast framework was 
      constructed in a way that ensures passive fit (PF) to use as control. Scanning 
      electron microscope (SEM) measured the implant abutment connection misfit. Sixty 
      screws were used on the corresponding frameworks. Screws were torqued and 
      pre-cyclic loading reverse torque value (RTV) was recorded. Frameworks were 
      subjected to 200,000 loading cycles with a loading point 9 mm from the center of 
      terminal implants adjacent to the cantilever and post-cyclic loading RTVs were 
      recorded. RESULTS: Microscopic readings showed significant differences between 
      frameworks. PF demonstrated the lowest measurements of 16.04 (2.6) microm while 
      CAD-cast demonstrated the highest measurements of 29.2 (3.1) microm. In all groups, 
      RTVs were significantly lower than the applied torque. Post-cyclic loading RTV 
      was significantly lower than pre-cyclic loading RTV in PF and 3DP frameworks. 
      Differences in RTVs between the three manufacturing techniques were 
      insignificant. CONCLUSION: Although CAD-cast and three-dimensionally printed 
      (3DP) both produce frameworks with clinically acceptable misfit, 3DP might not be 
      the technique of choice for maintaining screw's preload stability under an 
      aggressive loading situation.
CI  - (c) 2022 The Korean Academy of Prosthodontics.
FAU - Altuwaijri, Shahad Mohammmed
AU  - Altuwaijri SM
AUID- ORCID: 0000-0003-1477-3293
AD  - Department of Prosthetic Dental Sciences, College of Dentistry, King Saud 
      University, Riyadh, Kingdom of Saudi Arabia.
AD  - Department of Prosthetic Dental Sciences, College of Dentistry, Almajmaah 
      University, Almajmaah, Kingdom of Saudi Arabia.
FAU - Alotaibi, Hanan Nejer
AU  - Alotaibi HN
AUID- ORCID: 0000-0003-2549-8717
AD  - Department of Prosthetic Dental Sciences, College of Dentistry, King Saud 
      University, Riyadh, Kingdom of Saudi Arabia.
FAU - Alnassar, Talal Mughaileth
AU  - Alnassar TM
AUID- ORCID: 0000-0003-2974-4006
AD  - Department of Prosthetic Dental Sciences, College of Dentistry, King Saud 
      University, Riyadh, Kingdom of Saudi Arabia.
LA  - eng
PT  - Journal Article
DEP - 20220225
PL  - Korea (South)
TA  - J Adv Prosthodont
JT  - The journal of advanced prosthodontics
JID - 101521064
PMC - PMC8891687
OTO - NOTNLM
OT  - Cyclic loading
OT  - Dental implant
OT  - Preload
OT  - Reverse torque value (RTV)
OT  - Screw loosening
EDAT- 2022/03/15 06:00
MHDA- 2022/03/15 06:01
PMCR- 2022/02/01
CRDT- 2022/03/14 05:58
PHST- 2021/10/19 00:00 [received]
PHST- 2021/12/29 00:00 [revised]
PHST- 2022/02/15 00:00 [accepted]
PHST- 2022/03/14 05:58 [entrez]
PHST- 2022/03/15 06:00 [pubmed]
PHST- 2022/03/15 06:01 [medline]
PHST- 2022/02/01 00:00 [pmc-release]
AID - 10.4047/jap.2022.14.1.22 [doi]
PST - ppublish
SO  - J Adv Prosthodont. 2022 Feb;14(1):22-31. doi: 10.4047/jap.2022.14.1.22. Epub 2022 
      Feb 25.