Effect of khat extract on color stability of digitally and manually fabricated provisional restorations: an in vitro comparative study.

BACKGROUND: The aim of this in vitro study was to evaluate the effect of khat extract on the color stability of five different provisional restorative materials (PRMs). METHODS: In this study, 50 specimens were fabricated from five different PRMs with different techniques. Twenty specimens were digitally fabricated of poly-methyl methacrylate (PMMA) CAD/CAM milling and 3D printing PRMs, while the other thirty specimens were manually fabricated of three different PRMs: PMMA self-cured (SC) acrylic resin, light-cured (LC) composite, and Bis-acrylic SC composite. Milling and 3D printing machines were used to fabricate the digital specimens, while the manual specimens were fabricated using a metallic mold. The material was placed in the mold, covered by a polyester stripe, and held between two glass slabs with a constant load for 30 s. After setting, the specimens were removed and checked. Ten disc-shaped specimens with 2 ± 0.3 mm thickness and 10 ± 0.3 mm diameter were prepared from each of the tested PRM. Then all the specimens were polished. Five specimens of each PRM were immersed in khat extract, while the other five were immersed in distilled water medium as a control group. The color measurements were recorded before and after 1 and 7 days of immersion using a spectrophotometer. The immersion media were renewed every 24 h and kept along with the specimens at 37 °C. The T test, paired T test, and ANOVA analysis of variance were used to analyze the results. The Bonferroni test was used for post-hoc multiple comparisons. RESULTS: The interaction between the tested PRMs, the media, and the duration of immersion time was statistically significant (p < 0.05). PMMA CAD/CAM milling PRM was the most stable in color, and this was statistically significant (p < 0.05). The LC composite PRM composite was the least stable in color and was statistically insignificant (p > 0.05) when compared to the 3D printing and Bis-acrylic SC composite PRMs, respectively. CONCLUSIONS: This study demonstrated that khat extract medium has a high staining ability on the tested PRMs. CAD/CAM milling PRM was the most stable in color and could therefore be used as a long-term provisional. The increase in immersion time was a significant factor in the color change of the tested PRMs. The color of the 3D-printed PRM was the most affected over time.

Color stability of nanohybrid and microhybrid composites after immersion in common coloring beverages at different times: a laboratory study.

OBJECTIVE/AIM: This in vitro study aimed to evaluate the color stability of microhybrid and nanohybrid restorative composites after exposure to immersion media common in Yemen for different periods. MATERIALS AND METHODS: Two composite materials, nanohybrid Tetric N-Ceram and microhybrid Te-Econom Plus, were investigated. Six groups of 30 cylindrical specimens (n = 5/group; diameter, 10 mm; thickness, 2 mm; shade A2) of each restorative material were immersed for 1 week in distilled water, qat solution, Yemeni coffee, traditional Yemeni coffee (qishr), red tea, and Dilsi cola. Color changes were evaluated by colorimetry. The color data and pH were measured before and 1, 3, and 7 days after immersion. The data were statistically analyzed. RESULTS: Tetric N-Ceram showed lesser discoloration than did Te-Econom Plus. Qat, coffee, and red tea caused highly significant discoloration than did Dilsi cola and distilled water (p < 0.05). The role of low pH in discoloration depended on the colorant. DISCUSSION: Nanohybrid Tetric N-Ceram composites are more resistant to discoloration than are microhybrid Te-Econom Plus composites. Qat and coffee have the highest effect on composite discoloration. CONCLUSIONS: These findings will aid in selecting composite materials and patient instruction.

Evaluation of the quality of fixed prosthesis impressions in private laboratories in a sample from Yemen.

BACKGROUND: Fixed prosthodontics require an accurate impression for the teeth and the area to be restored for the laboratory to fabricate the desired restoration without mistakes. This study evaluated the quality of impressions received by private laboratories for the fabrication of fixed prosthesis by describing the frequency of clinically detectable errors and by analyzing association between the various factors involved. METHODS: 165 impressions were collected from four dental laboratories. Jaw involved, type of tray, size of tray, number of prepared units, type of impression materials, techniques and viscosity in case of elastomeric impressions and type of prosthesis requested were recorded. Data referring to errors and visible defects including errors in finish line, in preparation area, in silicone impression technique and blood in impression were also documented. Factors affecting errors present were also assessed. Association between dentist gender and experience years and impression errors was assessed. Chi square and Fisher exact tests used to examine the association between categorical variables and outcomes. RESULTS: The total of error considering not immediately pouring as an error. Alginate was the most impression used. of impressions evaluated (50.9%), 97% were have at least one visible error; 92.1% had errors in finish line, 53.9% had errors in preparation area and (72.8%) of elastomeric impressions were have at least one error in technique. Blood in impression was detected in 52.1% of impressions. Significant association was found between material type and errors in finishing line and preparation area. Significant relationships were found between gender and errors in silicone impression technique (p < 0.05). CONCLUSION: Within the limitations of this study, high frequency of detectable errors was found in fixed prosthesis impressions received by private dental laboratories. This high frequency is of serious concern, as this will result in poor fitted fixed prosthesis provided to patients.

Comparison between the Efficacy of Herbal and Conventional Dentifrices on Established Gingivitis.

BACKGROUND: Bacteria in dental plaque are one of the main factors causing periodontal disease. The aim was to evaluate and compare the effectiveness of antimicrobial dentifrices with herbal extracts and conventional toothpaste with no antimicrobial action for improvement of oral hygiene and reduction of gingival inflammation. METHODS: 48 volunteers with chronic marginal gingivitis were randomly divided into three groups. Groups 1 and 2 received herbal extract dentifrices. Group 3 used a conventional dentifrice. Subjects were asked to use the allocated dentifrice, three times a day, for 42 days. Values of Patient Hygiene Performance, Approximal Plaque, Gingival, and Sulcular Bleeding indices were assessed at baseline, after 14, 28 and 42 days. Data were analyzed by Student's t-test (α = 0.05). RESULTS: Oral hygiene (tooth brushing with dentifrices for 42 days) led to a significant decrease in plaque accumulation on smooth (by 61.2% and 57.2 in herbal test groups 1 and 2, respectively) and approximal (by 57.4 and 52.8% in herbal test groups 1 and 2, respectively) tooth surfaces, reduction of gingival inflammation (by 68.0 and 70.6% in herbal test groups 1 and 2, respectively) and gingival sulcus bleeding (by 79.5 and 81.2% in herbal test groups 1 and 2, respectively). Final indices values in both herbal test groups were significantly (P <60; 0.001) lower compared to those at baseline and those after 42 days in the conventional group. CONCLUSION: Continuous application of herbal tooth paste provided significant improvement of oral hygiene level in patients with gingivitis.

Influence of Khat Chewing on Periodontal Tissues and Oral Hygiene Status among Yemenis.

BACKGROUND: Khat chewing is popular among Yemenis. This study was performed to investigate the effects of khat chewing on periodontal tissue and oral hygiene status. METHODS: A total of 730 subjects (336 chewers and 394 non-chewers with a mean age of 31.5 ± 0.8 and 29.4 ± 0.9 years, respectively) were involved. Clinical data on periodontal tissues, oral hygiene sta-tus, gingival bleeding, burning sensation in the soft tissues, halitosis, ulcers in the oral cavity, difficulty in opening the mouth and swallowing solid food were collected to evaluate periodontal condition. Lo-gistic regression analysis, student t test and chi-squared test were employed according to which hypo-theses were being tested. RESULTS: The oral hygiene status of non-chewers was significantly better than that of chewers. The mean oral hygiene index of chewers was 2.12 ± 0.86 while that of non-chewers was 1.54 ± 1.12, the difference being statistically significant (P < 0.001). The incidence of gingival bleeding was signifi-cantly higher in khat-chewers. About 23% of chewers complained of difficulty in mouth-opening, as compared with only about 1% of non-chewers. Furthermore, 10% of chewers had difficulty in swal-lowing solid food. A burning sensation in the soft tissues was also found in a higher proportion of khat-chewers. Similarly, ulcers on the oral mucosa were present in about 7% of chewers, as com-pared to 0.5% of non-chewers. Gingival recession was present in about 51% and 26% of chewers and non-chewers, respectively. CONCLUSION: There does appear to be a relationship between the effect of chewing khat on peri-odontal tissue and oral hygiene status.