Abstract:

Aim of the study: The purpose of current study was to evaluate and compare the effect of different connector designs on the 

compressive strength of posterior inlay-retained fixed dental prostheses made from two different ceramic systems.

Materials and Methods: Twenty-eight inlay retained fixed partial denture (IRFPDs) were used to replace missing lower right first 

molar. According to the IRFPDs material (lithium disilicate ceramic and Zirconia), the specimens were divided into two main groups A 

and B (n=14). These groups were further subdivided into 2 sub-groups 1&2 (n=7) according to the connector designs used (round and 

sharp). The IRFPDs were manufactured using the hot press and CAD-CAM techniques respectively. All specimens were cemented using 

self-adhesive resin cement. Each specimen was placed on the test device, and compressive force was applied till the failure occurred. All 

the results obtained were statistically analyzed by two way ANOVA test and student t test (level of significance p < 0.05). 

Results: Revealed that the highest mean value of compressive strength was for round connector with zirconia IRFPDs. While the lowest 

value was for sharp connector with lithium disilicate IRFPDs.

Conclusions: Within the limitations of this in-Vitro study the following conclusion could be obtained; zirconia demonstrated high 

compressive strength than lithium disilicate. Despite the lithium disilicate possessed the lowest compressive strength values for both 

types of connector design. However these values were greater than the average occlusal force recorded in several studies.

Keywords: IRFPDs, Connector design, Fixed prosthesis, CAD/CAM, Zircoina, Lithium disilicate, Compressive strength.

Seed size is a key functional trait that affects plant fitness at the seedling stage and may

vary greatly with species fruit size, growth form and fecundity. Using structural equation

modelling (SEM) and correlated trait evolution analysis, we investigated the interaction network

between seed size and fecundity, postfire regeneration strategy, fruit size, plant height

and serotiny (on-plant seed storage) among 82 species of the woody shrub genus, Hakea,

with a wide spectrum of seed sizes (2–500 mg). Seed size is negatively correlated with fecundity,

while fire-killed species (nonsprouters) produce more seeds than resprouters

though they are of similar size. Seed size is unrelated to plant height and level of serotiny

while it scales allometrically with fruit size. A strong phylogenetic signal in seed size revealed

phylogenetic constraints on seed size variation in Hakea. Our analyses suggest a

causal relationship between seed size, fecundity and postfire regeneration strategy in

Hakea. These results demonstrate that fruit size, fecundity and evolutionary history have

had most control over seed size variation among Hakea species.

•This paper examines the ability of Libyan university students studying EFL to identify the language items which are called conjunctives and recognize their meanings and functions before they can benefit from them in their reading and writing skills