Here’s our monthly update of research abstracts that maybe of interest to readers:
- Microbial Leakage at Morse Taper Conometric Prosthetic Connection
Two 2 conometric systems were evaluated with one having copings of gold, and the other PEEK.
Microbial leakage occurred in both groups, and there was no statistically significant difference between groups. Microbial concentration resulted in a presence inferior to 1 × 10 copies/μL in all positive assemblies. Because of the low bacterial count, it can be concluded that a minimal bacterial infiltration may be allowed by conometric interfaces for prosthetic connection.1
- Comparison of maxillary anterior tooth width and facial dimensions of 3 ethnicities
The purpose of this observational study was to investigate the relationship between the mesiodistal dimensions of the 6 maxillary anterior teeth and the bizygomatic width, interpupillary distance, intercanthal distance, interalar width, and intercommissural width of individuals of Asian, African-American, and white ethnicities…No consistent ratios were found among the examined facial dimensions and the mesiodistal dimensions of the 6 maxillary anterior teeth among the 3 ethnicities, except for the central incisor width-to-bizygomatic width ratio. No correlations were found between the facial dimensions and mesiodistal dimensions of the 6 maxillary anterior teeth among the 3 ethnicities except in Asian women. For Asian women, the intercommissural width correlated with the width of the central incisor (P=.001), the width of 2 central incisors (P=.001), the width of 4 incisors (P=.003), and the width of 6 maxillary anterior teeth (P=.005)…No facial proportions by which the exact width of maxillary anterior teeth could be predicted were found in Asian, African-American, or white populations.2
- Effect of different housing retaining materials on the flexural strength of an acrylic resin overdenture base.
An attachment housing inside an overdenture may weaken the acrylic resin base. The type of housing retaining material may affect the strength of the housing retaining material-acrylic resin base assembly. The effect of different housing retaining materials on the strength of acrylic resin base is unknown…The purpose of this in vitro study was to evaluate the effects of different materials used to retain the housing on the flexural strength of a poly(methyl methacrylate) (PMMA) resin base….The tested retaining materials significantly reduced the flexural strength of PMMA denture base. The flexural strength of the resin base with housing was significantly higher when PMMA-based retaining materials were used than when acrylic resin-based hard reline materials were used.3
- Clinician-generated torque on abutment screws using different hand screwdrivers.
Many clinicians use hand screwdrivers to tighten prosthetic and abutment screws. The impact of the screwdriver type, the location of the implant, and the sex of the practitioner on the generated torque is not well understood. The purpose of this in vitro study was to compare the torque generated by different hand screwdrivers when used in the anterior and posterior regions and to evaluate the correlation between the applied torque and the sex and body mass index (BMI) of the practitioner…Significant differences were observed among the applied torque values when different screwdrivers were used (P<.001). Higher torque values were generated in the anterior region than in the posterior region (P<.001). The interaction of the sex and BMI of the participants significantly affected the generated torque values (P=.044)...The type of screwdriver and location of the implant affected the generated torque. Torque values generated by the large screwdriver were higher than those of small and medium screwdrivers. Higher torque was applied in the anterior region.4
1.Microbial Leakage at Morse Taper Conometric Prosthetic Connection: An In Vitro Investigation.
Bressan E, Stocchero M, Jimbo R, Rosati C, Fanti E, Tomasi C, Lops D.
Implant Dent. 2017 Oct;26(5):756-761.
2.Comparison of maxillary anterior tooth width and facial dimensions of 3 ethnicities.
Parciak EC, Dahiya AT, AlRumaih HS, Kattadiyil MT, Baba NZ, Goodacre CJ.
J Prosthet Dent. 2017 Oct;118(4):504-510.
3.Effect of different housing retaining materials on the flexural strength of an acrylic resin overdenture base.
Ozkir SE, Yilmaz B.
J Prosthet Dent. 2017 Oct;118(4):500-503.
4.Clinician-generated torque on abutment screws using different hand screwdrivers.
Alikhasi M, Kazemi M, Jalali H, Hashemzadeh S, Dodangeh H, Yilmaz B.
J Prosthet Dent. 2017 Oct;118(4):488-492.