Publications by authors named "T A Bakhsh"

31 Publications

The Effect of Thermocycling on Interfacial Bonding Stability of Self-Etch Adhesives: OCT Study.

Biomed Res Int 2021 8;2021:5578539. Epub 2021 Jun 8.

Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, P.O. Box 80209, Jeddah 215-89, Saudi Arabia.

Objective: The aim of this study was to monitor the behavior of interfacial gaps formed under different bonded polymeric restorations before and after thermocycling (TC), using swept-source optical coherence tomography (SS-OCT) and confirming the obtained findings with confocal laser scanning microscopy (CLSM).

Materials And Methods: Cylindrical class I cavities were prepared in twenty noncarious human premolar teeth (1.5 mm depth × 3.5 mm diameter) and divided randomly into two groups: TS and SN, according to the adhesive system ( = 10). In the TS group, one-step self-etch adhesive Clearfil Tri-S Bond Plus (Kuraray Noritake Dental, Japan) was used, followed by composite restoration using Estelite Sigma Quick (Tokuyama Dental, Japan). In the SN group, the cavities were restored with the two-step self-etch/composite silorane-based resin restoration system (3M ESPE, USA). All specimens were restored in bulk filling technique and cured in accordance with the manufacturers' instructions. Both groups were imaged under SS-OCT after 24 h and recorded as controls. Then, each group was subjected to thermal challenge using the TC machine (5-55°C) and B-scans were recorded at different TC intervals (2600, 5200, and 10000). In order to confirm the SS-OCT findings, additional specimens were prepared, scanned, and sectioned for CLSM observation.

Results: B-scans demonstrated white clusters at the tooth-resin interface that corresponded to the gap location on CLSM images. The TS group showed significantly less gap formation than the SN group before and after TC ( < 0.001).

Conclusions: An optimal composite adaptation can be achieved when the bonded restoration comprises a combination of an adhesive containing 10-MDP monomer and a considerable highly filled composite.
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http://dx.doi.org/10.1155/2021/5578539DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8208845PMC
June 2021

Nondestructive evaluation of microleakage in restored primary teeth using CP-OCT.

Niger J Clin Pract 2021 Jun;24(6):919-924

Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, P.O. Box 80209, Jeddah 215-89, Saudi Arabia.

Background: Although the demand for esthetic filling of primary teeth with resin composite is increasing, there is no enough data on the adhesive performance of composite restorations in primary teeth. Despite the improvements in resin composites, interfacial gap is still a disadvantage as it may cause marginal staining, secondary caries, and restoration failure. Previous studies have validated the efficiency of optical coherence tomography (OCT) in the evaluation of adhesive interface in permanent teeth, but not in primary teeth.

Aims: The aim of this study was to assess microleakage upon composite restorations in primary teeth using cross-polarization OCT (CP-OCT).

Methodology: Cylindrical class-V cavities were prepared in extracted human primary second molars and divided into four groups randomly. In groups 1 and 2, cavities were restored using Tetric N-Universal adhesive in the self-etch mode followed by IPS Impress Direct Composite and Ceram.x One Universal composite, respectively. In groups 3 and 4, one-step self-etch Prime and Bond Elect adhesive was used followed by ID composite and CX composite in groups 3 and 4, respectively. The specimens were then immersed in a contrasting solution followed by interfacial microleakage examination under CP-OCT. The recorded images were analyzed to quantify the mean gap percentages.

Results: All tested groups showed variable degree of interfacial microleakage under composite restorations. Two-way ANOVA showed the composite factor was significantly influencing the results, unlike the adhesive. Group 1 and 2 had the lowest and highest mean gap percentage, respectively, which were significantly different from the other groups. Groups 3 and 4 were not significantly different.

Conclusion: Based on the current finding, a polymeric restorative system from the same manufacturer reduces the risk of interfacial microleakage in primary teeth.
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http://dx.doi.org/10.4103/njcp.njcp_442_20DOI Listing
June 2021

Tomographic Evaluation of the Internal Adaptation for Recent Calcium Silicate-Based Pulp Capping Materials in Primary Teeth.

Biomed Res Int 2021 8;2021:5523145. Epub 2021 May 8.

Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, P.O. Box 80209, Jeddah 215-89, Saudi Arabia.

Objectives: To evaluate the internal adaptation of recent pulp capping materials (TheraCal and Biodentine) relative to MTA when used as indirect pulp capping for primary teeth.

Materials And Methods: Thirty primary molars were randomly allocated into three groups, group (A) was TheraCal, group (B) was Biodentine, and MTA was the control group (C). A standardized round class-V cavity (1.5 mm diameter and 2 mm depth) was prepared using a milling machine on the buccal surface of each tooth with the pulpal floor located on the dentin. Then, pulp-capping materials were applied. Finally, all teeth were restored by composite restoration. The internal adaptation of the pulp-capping materials to the dentinal surface was investigated by microcomputed tomography (Micro-CT) to determine the internal gap volume, and by optical coherence tomography (OCT) to determine the high-intensity reflection of light from the floor.

Results: Based on Micro-CT findings, TheraCal showed significantly higher internal gap volume than both MTA and Biodentine ( < 0.001), while MTA and Biodentine did not show a significant difference in the gap volume. Based on the OCT findings, TheraCal showed a significantly higher intensity of light reflection than both MTA and Biodentine ( < 0.001); however, there was no significant difference between MTA and Biodentine. Pearson's correlation test showed that there was a strong positive correlation between Micro-CT and OCT ( = 0.686, = 30, < 0.001).

Conclusions: Biodentine and MTA showed a comparable result in terms of their internal adaptation on the dentinal surface of the primary teeth, and both were better than TheraCal. There is a moderate to a strong positive correlation between Micro-CT and OCT in the measurement of internal adaptation of the tested pulp capping materials. OCT can be helpful and beneficial for the clinical setting and allow dentists to screen and evaluate restorations during follow-up.
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http://dx.doi.org/10.1155/2021/5523145DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8128549PMC
May 2021

A Novel Evaluation Method for Detecting Defects of the Bonded Orthodontic Bracket-Tooth Interface.

Biomed Res Int 2021 15;2021:6634595. Epub 2021 Mar 15.

Operative and Esthetic Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.

Background: Orthodontic patients are at high risk to develop caries. This study is introducing a clinical method detecting interfacial defects between ceramic brackets and enamel utilizing optical coherent tomography in addition to using the nanoleakage expression in vitro test.

Methods: Transbond XT primer and moisture insensitive primer (MIP) were bonded to 75 human premolar enamel surfaces and divided into (XTD), (MIPD), and (MIPW) groups. The (XTD) and (MIPD) groups had ceramic brackets bonded to dry enamel surfaces using TransBond and moisture insensitive primers, respectively, while the (MIPW) samples were bonded to moist enamel using moisture insensitive primer. All specimens were examined under crosspolarization optical coherence tomography. Debonding forces of the brackets to 45 teeth (15 teeth/group). 30 bonded specimens (15 specimens/group) were cross-sectioned to detect the nanoleakage expression using scanning electron microscope equipped with energy-dispersive spectroscopy (SEM/EDS). The degree of conversion of the specimens in the experimental groups was tested using attenuated total reflectance Fourier transform infrared spectroscopy (FTIR/ATR).

Results: Optical coherence tomography detected the interfacial defects between the ceramic brackets and tooth structure. One way ANOVA showed that (XTD) and (MIPD) groups recorded significantly higher bond strength values and less nanoleakage expression when compared to MIPW ( > 0.05).

Conclusions: Optical coherence tomography can be utilized to detect interfacial adhesive-tooth defects. Dry enamel surfaces improve the quality of the enamel/primer interface (200 words).
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http://dx.doi.org/10.1155/2021/6634595DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7987444PMC
May 2021

Evaluation of microleakage in class-II bulk-fill composite restorations.

J Dent Sci 2020 Dec 11;15(4):486-492. Epub 2020 May 11.

Restorative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.

Background/purpose: Despite the clinical appeal of restoring deep class II cavities in single increment using bulk-fill resin composite, sealing of bulk-filled composite restorations is a concern. This study evaluated interfacial adaptation of bulk-fill composite restoration to axial wall and gingival floor of class II cavities using cross-polarization optical coherence tomography (CP-OCT).

Materials And Methods: Box-shaped class II cavities were prepared in extracted molars and divided into three groups ( = 7) according to adhesive used; Clearfil SE Bond 2 (SE2), Tetric-N Bond Self-Etch (TSE) or Tetric-N Bond Universal (TNU). All adhesives were applied in self-etch mode and according to manufacturers' recommendation. Then, preparations were bulk-filled with Filtek Bulk Fill Posterior Restorative resin composite and immersed in a contrast agent. Tomographic images of axial wall and gingival floor of each restoration were obtained by CP-OCT (IVS-300, Santec) with a central wavelength of 1330 nm and were imported to an image analysis software to quantify microleakage.

Results: Mann-Whitney U test showed statistically significant difference in microleakage percentage between the groups at both axial wall and gingival floor ( < 0.05). SE2 group had the lowest percentage of microleakage ( < 0.05), as only few cross-sections showed areas of reflections from contrast agent penetrating into axial wall (8.23 ± 6.8) and gingival floor (7.07 ± 4.1), followed by TNU group (18.13 ± 12.9 axially and 30.61 ± 11.9 gingivally). Microleakage was frequently observed at the axial wall and gingival floor of TSE group, showing the highest percentages of 25.50 ± 12.5 and 36.97 ± 10.2, respectively ( < 0.05).

Conclusion: All tested groups exhibited different extent of interfacial microleakage, however, two-step self-etch adhesive yielded superior adaptation in comparison to one-step self-etch adhesive and universal adhesive.
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http://dx.doi.org/10.1016/j.jds.2020.04.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7816009PMC
December 2020
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