| 1. |
- Ghariani, L, et al.
(författare)
-
Does crown/implant ratio influence the survival and marginal bone level of short single implants in the mandibular molar? : A preliminary investigation consisting of 12 patients
- 2016
-
Ingår i: Journal of Oral Rehabilitation. - : John Wiley & Sons. - 1365-2842 .- 0305-182X. ; 43:2, s. 127-135
-
Tidskriftsartikel (refereegranskat)abstract
- Crown/implant (C/I) ratio has been proven to not affect the survival of the implants; however, it is also a fact that no evidence exists with regard to the use of single short implants in the mandibular molar. The aim of this study was to determine whether the crown/implant ratios of single implant-supported fixed restorations on implants of 6-8 mm in the mandibular molar have an impact on the implant survival and marginal bone maintenance. Twelve short dental implants (6-8 mm) were installed and restored with single crowns, loaded after 3 months of healing. The restorations were divided according to crown-to-implant ratio into two groups: Group 1: C/I < 2.0 and Group 2: C/I >== 2.0. Alveolar bone loss was measured using CBCT scan, taken at the implant placement and after 12 months follow-up from loading. Reduced implant/crown ratio shown no statistic significant differences on implant survival and the alveolar bone level compared with recommended implant/crown ratio. Within the limitation of this study, it can be concluded that reduced C/I ratio could be used as a substitute for recommended C/I ratio in severely mandibular atrophic residual alveolar ridges.
|
|
| 3. |
- Rayyan, Mohammad M., et al.
(författare)
-
Comparison of interim restorations fabricated by CAD/CAM with those fabricated manually
- 2015
-
Ingår i: The Journal of prosthetic dentistry (Print). - : Mosby. - 0022-3913 .- 1097-6841. ; 114:3, s. 414-419
-
Tidskriftsartikel (refereegranskat)abstract
- Statement of problem. Interim restorations represent an essential treatment step; however, the optimal resin material for long-term interim restorations requires investigation. Purpose. The purpose of this in vitro study was to compare the color stability, water sorption, wear resistance, surface hardness, fracture resistance, and microleakage of computer-aided design/computer-aided manufacturing-(CAD/CAM) fabricated interim restorations with those of manually fabricated interim restorations. Material and methods. Epoxy replicas were made from a prepared maxillary first premolar. On the replicas, interim crowns were fabricated and divided into the following groups: CAD/CAM poly(methyl methacrylate) (PMMA) blocks (CC), autopolymerizing temporary resin (AP), automix temporary resin (AM), and thermoplastic resin (TP). After cementation, all specimens were subjected to thermocycling and dynamic fatigue. The CIE Laboratory color coordinates were then recorded before and after immersion in coffee, tea, carbonated cola, and red wine. Water sorption was evaluated by using an immersion technique. Wear resistance was measured in a surface abrasion device. Vickers microhardness was measured on polished specimens. Fracture resistance was evaluated by axial loading with a universal testing machine. Marginal dye penetration was evaluated by sectioning the interim restorations after immersion in methylene blue (alpha=.05). Results. Colorimetric analysis revealed a large degree of color alteration (SE) in the manually fabricated interim restorations: AP = Delta E of 6.7 +/- 2); AM = Delta E of 7.1 +/- 1.5), and TP = Delta E of =5.4 +/- 3.1. The CC group demonstrated color stability (Delta E=2.1 +/- 0.2). CAD/CAM interim restorations demonstrated significantly lower water sorption, higher wear resistance, higher surface hardness, and significantly higher fracture resistance (1 289 +/- 56N) compared with manually fabricated interim restorations (AP=996 +/- 45, AM=899 +/- 37, and TP=1179 +/- 41). The stereomicroscopic examination of sectioned specimens demonstrated the absence of dye penetration in all tested specimens. Conclusions. CAD/CAM interim crowns presented stable physical and mechanical properties and may be used for long-term interim restorations.
|
|
