Spectrophotometric insights: calcium hydroxide influences tooth discolorations induced by short-term application of antibiotic/corticosteroid pastes.

OBJECTIVES: This in vitro study aimed to assess the influence of a calcium hydroxide dressing regarding the relative color change (ΔE) of enamel-dentin specimens previously exposed to antibiotic/corticosteroid pastes. MATERIALS AND METHODS: Eighty bovine enamel-dentin specimens with a cylindrical central cavity were randomly allocated to four groups: NEG (empty), POS (blood), LED (Ledermix), and ODO (Odontopaste) (n = 20 each). The materials were applied and sealed with self-adhesive resin luting material. After 3 weeks, the materials were removed and a calcium hydroxide (Ca(OH)2) dressing was placed in all cavities. After a further 3-week storage period, the cavities were restored with resin-based composite. Spectrophotometric color measurements were taken over 6 months, and ΔE values were calculated. A Tukey's multiple comparison test was performed to assess significant differences within the treatment groups (p < 0.05). RESULTS: Tooth discolorations were present after 3 weeks in LED (ΔE 29.14 ± 6.55) and POS (ΔE 18.05 ± 7.03); NEG and ODO remained color stable (ΔE 3.2 ± 1.36 and ΔE 2.3 ± 1.16). The 3-week Ca(OH)2 dressing decreased discolorations of POS (ΔE 15.93 ± 6.63; p = 0.37), whereas LED showed a further significant increase (ΔE 39.55; p < 0.0001). Between the end of the Ca(OH)2 dressing and the final restoration no significant color changes were observed in any group (p > 0.9). CONCLUSIONS: Discolorations induced by LED progressed during the Ca(OH)2 dressing despite careful removal of all residues. CLINICAL RELEVANCE: Calcium hydroxide might negatively affect the discoloring potential of Ledermix. This highlights the need for direct intracanal application methods of Ledermix ensuring a material-free access cavity or alternative antibiotic/corticosteroid pastes such as Odontopaste should be used.

Systemically administered amoxicillin/ metronidazole versus azithromycin as adjuncts to subgingival instrumentation during non-surgical periodontal therapy. A systematic review.

The aim of this systematic review was to compare the combination of amoxicillin and metronidazole or azithromycin when used as adjunct systemic antibiotics during the non-surgical periodontal therapy of chronic periodontitis. The databases Medline, Embase, Cochrane and Biosis were electronically searched. Additionally, a hand search was conducted up to24 October 2019. From 76 papers, only two papers could be included in the analysis. The calculated mean probability of having probing depth (PD) ≤ 3 mm after non-surgical periodontal therapy in moderate (4-6 mm) and deep (> 6 mm) pockets accounted for 7% and 6% for the combination of amoxicillin and metronidazole. For azithromycin it was 3% and 1%, respectively. The mean probability of persisting pockets ≥ 5 mm was 0 for moderate pockets with both antibiotic therapies whereas for deep pockets therapy with amoxicillin and metronidazole seems slightly lower. On the basis of two studies included in this systematic review, azithromycin as an adjunct to scaling and root planing in the non-surgical adjunctive treatment of chronic periodontitis seems to provide clinical results similar to the combination of amoxicillin and metronidazole. On behalf of patients' compliance and well-being, the use of azithromycin as an adjunct to non-surgical periodontal therapy of chronic periodontitis may be a substitute to amoxicillin and metronidazole. However, interpretation should be taken with caution, since the results are based on two studies only; thus, further clinical trials are necessary to underline or refute this trend.

Comparing the Antimicrobial In Vitro Efficacy of Amoxicillin/Metronidazole against Azithromycin-A Systematic Review.

On account of its proven clinical efficacy, the combination of systemically administered amoxicillin and metronidazole is frequently adjuncted to non-operative periodontal therapy and well documented. Potential drawbacks of this regimen, e.g., side effects and problems with the compliance, led to an ongoing search for alternatives. Azithromycin, an antibiotic extensively used in general medicine, has recently found its niche in periodontal therapy as well. This systematic review aimed to analyze the in vitro antimicrobial efficacy of amoxicillin plus metronidazole versus azithromycin. For this purpose, a systematic literature search was performed, and studies published up to 29 March 2018 referenced in Medline, Embase, Cochrane, and Biosis were independently screened by two authors. An additional hand search was performed and studies focusing on the evaluation of in vitro antimicrobial efficacy of amoxicillin + metronidazole or azithromycin on bacteria from the subgingival biofilm were included. English and German language research reports were considered. From 71 identified articles, only three articles were eligible for inclusion. These studies showed heterogeneity in terms of analytical methods and strains explored. However, all studies used multispecies biofilm models for analysis of the antimicrobial activity. Unanimously, studies reported on more pronounced antimicrobial effects when applying the combination of amoxicillin + metronidazole, compared to azithromycin. Based on the few studies available, the combination of amoxicillin + metronidazole seemed to display higher antimicrobial efficacy in vitro than azithromycin.

Dental Students' Perceptions of Digital and Conventional Impression Techniques: A Randomized Controlled Trial.

The aim of this randomized controlled trial was to analyze inexperienced dental students' perceptions of the difficulty and applicability of digital and conventional implant impressions and their preferences including performance. Fifty undergraduate dental students at a dental school in Switzerland were randomly divided into two groups (2×25). Group A first took digital impressions in a standardized phantom model and then conventional impressions, while the procedures were reversed for Group B. Participants were asked to complete a VAS questionnaire (0-100) on the level of difficulty and applicability (user/patient-friendliness) of both techniques. They were asked which technique they preferred and perceived to be more efficient. A quotient of "effective scan time per software-recorded time" (TRIOS) was calculated as an objective quality indicator for intraoral optical scanning (IOS). The majority of students perceived IOS as easier than the conventional technique. Most (72%) preferred the digital approach using IOS to take the implant impression to the conventional method (12%) or had no preference (12%). Although total work was similar for males and females, the TRIOS quotient indicated that male students tended to use their time more efficiently. In this study, dental students with no clinical experience were very capable of acquiring digital tools, indicating that digital impression techniques can be included early in the dental curriculum to help them catch up with ongoing development in computer-assisted technologies used in oral rehabilitation.

Time efficiency, difficulty, and operator's preference comparing digital and conventional implant impressions: a randomized controlled trial.

OBJECTIVES: The aim of this randomized controlled trial was to analyze implant impression techniques applying intraoral scanning (IOS) and the conventional method according to time efficiency, difficulty, and operator's preference. MATERIAL AND METHODS: One hundred participants (n = 100) with diverse levels of dental experience were included and randomly assigned to Group A performing digital scanning (TRIOS Pod) first or Group B conducting conventional impression (open tray with elastomer) first, while the second method was performed consecutively. A customized maxillary model with a bone-level-type implant in the right canine position (FDI-position 13) was mounted on a phantom training unit realizing a standardized situation for all participants. Outcome parameter was time efficiency, and potential influence of clinical experience, operator's perception of level of difficulty, applicability of each method, and subjective preferences were analyzed with Wilcoxon -Mann-Whitney and Kruskal-Wallis tests. RESULTS: Mean total work time varied between 5.01 ± 1.56 min (students) and 4.53 ± 1.34 min (dentists) for IOS, and between 12.03 ± 2.00 min (students) and 10.09 ± 1.15 min (dentists) for conventional impressions with significant differences between the two methods. Neither assignment to Group A or B, nor gender nor number of impression-taking procedures did influence working time. Difficulty and applicability of IOS was perceived more favorable compared to conventional impressions, and effectiveness of IOS was rated better by the majority of students (88%) and dentists (64%). While 76% of the students preferred IOS, 48% of the dentists were favoring conventional impressions, and 26% each IOS and either technique. CONCLUSIONS: For single-implant sites, the quadrant-like intraoral scanning (IOS) was more time efficient than the conventional full-arch impression technique in a phantom head simulating standardized optimal conditions. A high level of acceptance for IOS was observed among students and dentists.

In vitro assessment of the tooth staining potential of endodontic materials in a bovine tooth model.

BACKGROUND/AIMS: Traumatized teeth requiring endodontic intervention may discolor as a result of the treatment performed. Thus, the aim was to investigate the discoloration potential of different endodontic cements, dressings, and irrigants used in dental traumatology. MATERIALS AND METHODS: Cylindrical cavities were prepared in 330 bovine enamel-dentine blocks (10 × 10 × 3.5 mm), leaving 2 mm of enamel and dentine on the labial side. The specimens were randomly assigned to 22 groups (n = 15). The cavities were filled with a range of endodontic materials, sealed with composite and stored in physiological saline. The color of the labial enamel surface was measured with a spectrophotometer at 7 time intervals: before (T0) and after the placement of the test material (T1 = baseline), after 1 week (T2), 1 month (T3), 3 months (T4), 6 months (T5), and 12 months (T6). The color difference values (ΔE) were calculated and further analyzed by anova and the Tukey-Kramer post hoc test (α = 0.05). RESULTS: After 12 months, significant staining was observed among the endodontic cements only in the Portland cement group with additional bismuth oxide (H-MED PC BiOx; ΔE 22.2). Specimens with other commercially available calcium silicate cements containing bismuth oxide were not significantly discolored. All specimens with endodontic dressings and irrigants were color stable except the tested triple antibiotic paste (M-TreVitaMix; ΔE 14.9) and the double antibiotic paste (N-BiMix; ΔE 14.9). Both mixtures did not contain tetracycline derivatives. CONCLUSIONS: The presence of bismuth oxide in calcium silicate cements was not shown to be a reliable predictor for tooth discoloration. Antibiotic pastes without tetracycline derivatives do not guarantee the color stability of teeth.

Influence of the bleaching interval on the luminosity of long-term discolored enamel-dentin discs.

OBJECTIVES: The aim of this study is to investigate the influence of changing the sodium perborate-tetrahydrate (PBS-4) at a 4-day interval versus no change after 16 days of internal bleaching. MATERIALS AND METHODS: Two hundred and ten bovine enamel-dentin discs were discolored for 3.5 years with 14 different endodontic materials. All groups with a discoloring index of ∆E (mean) ≥ 5.5 were included in the present investigation: ApexCal (APCA), MTA white + blood (WMTA+BL), Portland cement + blood (PC+BL), blood (BL), MTA gray (GMTA), MTA gray + blood (GMTA+BL), Ledermix (LED), and triple antibiotic paste containing minocycline (3Mix). Fourteen specimens of each group were randomly assigned into two treatment groups: (1) no change of the PBS-4 (n = 7); (2) change of the PBS-4 every 4 days (n = 7). Color measurements were taken at 10 different time intervals and the L*a*b* values were recorded with a spectrophotometer (VITA Easyshade® compact). RESULTS: In the group 3Mix, significantly better results were achieved by changing the bleaching agent every 4 days (P = 0.0049; q = 0.04), while the group WMTA+BL indicated better results by no change of the bleaching agent (P = 0.0222, q = 0.09). All remaining groups showed no statistical difference between the two treatment procedures. CONCLUSIONS: Moderate discolorations can be successfully treated without changing the bleaching agent over a period of 16 days. Changing the sodium perborate-tetrahydrate every 4 days is preferred in case of severe discolored enamel-dentin discs only. CLINICAL RELEVANCE: This approach may offer a reduced number of clinical appointments and a secondary cost reduction to the patient.

[prepCheck computer-supported objective evaluation of students preparation in preclinical simulation laboratory]. / prepCheck computergestützte objektive Beurteilung von Zahnpräparationen im Simulationslabor.

Applications such as “prepCheck” allow objective and consistent judgments of tooth preparations. Hereby the respective preparation is matched with a standardized preparation. Whereas the learning curve in the beginning is time-consuming, after some time the faculty members will be relieved from additional mentoring time in the preclinical simulation laboratory. Students independently get an objective self-assessment by the software. Time and effort at the moment are in a misbalance since three scans (preparation, occlusion record, opposite jaw) are necessary. A simple one-scan procedure would be preferable. “prepCheck” is considered as a user-friendly software. It will play an essential role in the objective assessment of students tooth preparations in the future education.

Tooth discoloration induced by endodontic materials: a literature review.

It is common knowledge that materials used in endodontics may cause discoloration and thus impair the aesthetic outcome of the treated tooth. The purpose of this review is to summarise the existing knowledge on the discoloration potential of materials used for endodontic procedures. A comprehensive literature search covering the period from 1966 to 2011 was conducted on Pubmed and the Cochrane Library using different keyword combinations including 'tooth', 'colour', 'discoloration', 'staining', 'endodontic''root canal''sealer', 'dressing', 'medicament', 'obturation', 'filling', 'treatment', 'portland cement', 'MTA' and 'antibiotic paste'. Any relevant work published in the English language in peer-reviewed journals and presenting pertinent information related to the purpose of this overview was considered for inclusion. In addition, bibliographies of all relevant papers and previous review articles were hand searched and the reference lists from endodontic textbooks were also reviewed. Articles were excluded if an English abstract was unavailable, if only single clinical reports or conference reports were included, or if the topic was unrelated to the subject. Ten in-vitro studies, one randomized controlled trial and one multicenter randomized controlled trial met the inclusion criteria. There were not any recently used endodontic materials that would not induce at least measurable colour changes. For a wide range of materials currently available on the market there is only scarce or no evidence available on their staining ability. Endodontic therapy should not focus solely on biological and functional aspects, but take aesthetic considerations into account as well. To reduce the risk of material-induced tooth discoloration all materials should be applied carefully in areas of aesthetic concern. The need for further research in this field and for the development of non-staining endodontic materials is evident.