A scanning electron microscopic evaluation of human dentinal tubules according to age and location

Carrigan, Patrick J.; Morse, Donald R.; Furst, Merrick L.; Sinai, Irving H.

doi:10.1016/s0099-2399(84)80155-7

Cited by 216 publications

(181 citation statements)

References 11 publications

Supporting

Mentioning

137

Contrasting

Unclassified

Order By: Relevance

“…In addition, in the young roots, no obvious differences were observed among the locations. As reported previously, 28 we found that the cervical dentine tubules were larger and denser than those in the lower portions in both age groups. Micro-indentation at the cervix involves more empty space of tubules and less intertubular dentine than at the apex, which causes micro-hardness to decrease more pronouncedly in the cervical dentine than in the apical dentine.…”

Section: Discussionsupporting

confidence: 90%

The effects of ageing on the biomechanical properties of root dentine and fracture

Zheng

Shao

et al. 2014

Journal of Dentistry

View full text Add to dashboard Cite

j o u r n a l o f d e n t i s t r y 4 2 ( 2 0 1 4 ) 3 0 5 -3 1 1 a r t i c l e i n f o Objectives: Knowledge of the mechanical behaviour of root dentine can facilitate better understanding of spontaneous vertical root fracture (VRF), an age-related disease initiated mainly at the root apex. We tested the hypothesis that the biomechanical properties of root dentine change with ageing.Methods: Sixteen human premolars were divided into ''old'' (17-30 years) and ''young'' (50-80 years) groups. The elastic modulus, nano-hardness, micro-hardness, elemental contents, tubular density/area of root dentine in cervical, middle and apical root regions were evaluated using atomic force microscopy-based nano-indentation, Knoop indentation, scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. Results:The apical dentine showed a lower nano-hardness, a lower elastic modulus, a lower calcium content, a lower calcium-to-phosphorus ratio and a smaller tubular density/area than the cervical dentine in both age groups, whereas spatial differences in micro-hardness were observed only in old roots. Compared with young dentine, old dentine showed a greater hardness, a higher elastic modulus, a greater mineral content and a smaller tubular size in the cervical portion, whereas the age-induced changes in tubular density were insignificant. Finite element analysis revealed that due to its higher elastic modulus, old apical dentine has a higher stress level than young dentine. Conclusions:The intrinsic material properties of root dentine have spatial variations, and they are altered by ageing. The higher stress level in old apical dentine may be one reason, if not the most important one, why spontaneous VRFs are more likely to occur in the elderly population.

show abstract

Section: Discussionsupporting

confidence: 90%

The effects of ageing on the biomechanical properties of root dentine and fracture

Zheng

Shao

et al. 2014

Journal of Dentistry

View full text Add to dashboard Cite

show abstract

“…Therefore, considering the stability of bond strength in SB within different regions and over time, it maybe stated that SB had a certain tolerance to the surface moisture or water content of dentin 23,25) . Moreover, tubule diameter and tubule density decrease from cervical to apical dentin 26,27) . If resin tag formation was the only factor affecting the adhesion, the µTBS would have decreased in the apical region.…”

Section: Discussionmentioning

confidence: 98%

Long-term regional bond strength of three MMA-based adhesive resins in simulated vertical root fracture

et al. 2011

View full text Add to dashboard Cite

The purpose of this study was to investigate bond durability of MMA-based adhesives to root dentin in a simulated complete vertical root fracture (CVRF). The fractured fragments of human premolar root were reattached using Super-Bond C&B (SB; Sun Medical), M-Bond or M-Bond II (MB or MB II; Tokuyama Dental). After storage for 1 day, 1 month, 6 months and 1 year, the reattached specimens were subjected to microtensile bond strength (µTBS) test at cervical and apical regions. Results showed that µTBS was significantly higher to cervical dentin than to apical dentin in MB and MB II, but not SB (p<0.05). Significant decrease in µTBS was found for MB and MB II after 1 year, whereas no significant difference was found for SB (p<0.05). Analysis of failure mode by SEM indicated differences over time. In conclusion, significant differences were found in the regional bond durability among MMA-based adhesives used to restore CVRF, that may lead to different clinical performances.

show abstract

“…Thus, although the regression of mTBS with proximity to the apex can be demonstrated for some materials, its causes are not clear from the results of the current study. Factors such as changes in the dentin structure could play a role in these relationships [28,29].…”

Section: Discussionmentioning

confidence: 99%

Microtensile bond strength between adhesive cements and root canal dentin

et al. 2003

View full text Add to dashboard Cite

Objectives: The hypotheses tested were that the bond strength of adhesive cements to root canal dentin (1) would be reduced as a function of con®guration factor, polymerization process and type of luting material and (2) would be lowered near the apex of the tooth.Methods: Human canines and premolars were prepared for post cementation using Single Bond/Rely X ARC, ED Primer/Panavia F, C and B Metabond, and Fuji Plus. The specimens were divided into two groups. For intact roots, the posts were luted using standard clinical procedures. For¯at roots, the posts were applied directly into¯at ground canals. All roots were sectioned into 0.6 mm thick slices, trimmed mesio-distally and stressed to failure at 1 mm/min. The mTBS of each slab was calculated as the force at failure divided by the bonded crosssectional surface area. The results were compared using a one-way ANOVA and Tukey multiple comparison intervals a 0:05: Least squares linear regression analysis was used to assess the effect of dentin location on bond strength.Results: All cements showed signi®cantly p # 0:05 lower bond strengths in intact vs.¯at roots. The mTBS of posts to intact roots were not signi®cantly different for Single Bond/Rely X ARC and Panavia F, but both were signi®cantly lower p # 0:05 than the bonds produced by C and B Metabond and Fuji Plus cements. For Single Bond/Rely X ARC and Fuji Plus a signi®cant decrease in bond strength was observed in dentin closer to the apex of the root.Signi®cance: Stresses from polymerization shrinkage and problems with adequate access to the root canal complicate the formation of high-strength bonds when cementing endodontic posts with resin cements. q

show abstract

A scanning electron microscopic evaluation of human dentinal tubules according to age and location

Cited by 216 publications

References 11 publications

The effects of ageing on the biomechanical properties of root dentine and fracture

The effects of ageing on the biomechanical properties of root dentine and fracture

Long-term regional bond strength of three MMA-based adhesive resins in simulated vertical root fracture

Microtensile bond strength between adhesive cements and root canal dentin

Contact Info

Product

Resources

About