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Purpose To evaluate the residual surface roughness of 5 common diamond-coated interproximal reduction (IPR) systems after consecutive in vitro applications in relation to system, diamond grain size, and instrument thickness. Methods IPR was performed on 80 extracted human incisors using motor-driven strips and discs under predefined conditions. The IPR auxiliaries were applied at 5 consecutive sessions of 20 s on intact interproximal surfaces, and the surface profile (Ra, Rz, Rmax) was analyzed at baseline and after each session with an optical profilometer. Results No overall significant difference in the roughness values was found between systems (P = 0.07 for Ra, P = 0.33 for Rz, and P = 0.48 for Rmax). There was a significant average decrease of Ra, Rz, and Rmax for all systems for every unit increase in time by −0.171 μm (P P ≤ 0.001), and −2.788 μm (P = 0.001), respectively. Ra, Rz, and Rmax values increased significantly, i.e., by 0.194 μm (P = 0.003), 5.890 μm (P = 0.001), and 5.319 μm (P = 0.010) as instrument thickness increased by one unit. No significant reductions in Ra, Rz, and Rmax were observed across grain sizes (−0.008 μm [P > 0.05], −0.244 μm [P > 0.05], and −0.179 μm [P > 0.05], respectively). There was no evidence of interaction between system and time as the P values for Ra, Rz, and Rmax were 0.88, 0.51, and 0.70, respectively. Conclusions All IPR materials presented significant gradual decrease of surface roughness after repeated applications. There were no significant roughness changes among auxiliaries of different grain sizes. Thinner auxiliaries showed significantly more roughness reduction, possibly requiring more frequent replacement than thick auxiliaries in clinical practice.

Purpose: To evaluate the residual surface roughness of 5 common diamond-coated interproximal reduction (IPR) systems after consecutive in vitro applications in relation to system, diamond grain size, and instrument thickness. Methods: IPR was performed on 80 extracted human incisors using motor-driven strips and discs under predefined conditions. The IPR auxiliaries were applied at 5 consecutive sessions of 20 s on intact interproximal surfaces, and the surface profile (Ra, Rz, Rmax) was analyzed at baseline and after each session with an optical profilometer. Results: No overall significant difference in the roughness values was found between systems (P = 0.07 for Ra, P = 0.33 for Rz, and P = 0.48 for Rmax). There was a significant average decrease of Ra, Rz, and Rmax for all systems for every unit increase in time by −0.171 μm (P < 0.001), −3.297 (P ≤ 0.001), and −2.788 μm (P = 0.001), respectively. Ra, Rz, and Rmax values increased significantly, i.e., by 0.194 μm (P = 0.003), 5.890 μm (P = 0.001), and 5.319 μm (P = 0.010) as instrument thickness increased by one unit. No significant reductions in Ra, Rz, and Rmax were observed across grain sizes (−0.008 μm [P > 0.05], −0.244 μm [P > 0.05], and −0.179 μm [P > 0.05], respectively). There was no evidence of interaction between system and time as the P values for Ra, Rz, and Rmax were 0.88, 0.51, and 0.70, respectively. Conclusions: All IPR materials presented significant gradual decrease of surface roughness after repeated applications. There were no significant roughness changes among auxiliaries of different grain sizes. Thinner auxiliaries showed significantly more roughness reduction, possibly requiring more frequent replacement than thick auxiliaries in clinical practice.

Purpose: To evaluate the residual surface roughness of 5 common diamond-coated interproximal reduction (IPR) systems after consecutive in vitro applications in relation to system, diamond grain size, and instrument thickness. Methods: IPR was performed on 80 extracted human incisors using motor-driven strips and discs under predefined conditions. The IPR auxiliaries were applied at 5 consecutive sessions of 20 s on intact interproximal surfaces, and the surface profile (Ra, Rz, Rmax) was analyzed at baseline and after each session with an optical profilometer. Results: No overall significant difference in the roughness values was found between systems (P = 0.07 for Ra, P = 0.33 for Rz, and P = 0.48 for Rmax). There was a significant average decrease of Ra, Rz, and Rmax for all systems for every unit increase in time by −0.171 μm (P < 0.001), −3.297 (P ≤ 0.001), and −2.788 μm (P = 0.001), respectively. Ra, Rz, and Rmax values increased significantly, i.e., by 0.194 μm (P = 0.003), 5.890 μm (P = 0.001), and 5.319 μm (P = 0.010) as instrument thickness increased by one unit. No significant reductions in Ra, Rz, and Rmax were observed across grain sizes (−0.008 μm [P > 0.05], −0.244 μm [P > 0.05], and −0.179 μm [P > 0.05], respectively). There was no evidence of interaction between system and time as the P values for Ra, Rz, and Rmax were 0.88, 0.51, and 0.70, respectively. Conclusions: All IPR materials presented significant gradual decrease of surface roughness after repeated applications. There were no significant roughness changes among auxiliaries of different grain sizes. Thinner auxiliaries showed significantly more roughness reduction, possibly requiring more frequent replacement than thick auxiliaries in clinical practice.

There is increasing evidence that the excessive consumption of acidic drinks and foods contributes to dental erosion and may be an important contributing factor for erosive tooth wear. The aims of the present contribution were twofold: (1) to assess the erosive potential of 116 dietary substances and medications; (2) to determine the chemical properties with an impact on the erosive potential. Using 300 deciduous and 1,020 permanent human teeth, enamel specimens were prepared and a pellicle was formed with human saliva. The erosive potential of the tested agents was quantified as the change in surface hardness of the specimens after 2 min of erosion. To characterise these agents, the following chemical properties were determined: pH, titratable acidity to pH 7, concentrations of Ca, Pi and F, as well as the degree of saturation with respect to hydroxyapatite. We conclude that some drinks, foodstuffs and medications may cause erosion. However, pH is not the only decisive factor, since some acidic substances did not cause dental erosion.

The purpose of this work was to analyze the shear bond strength (SBS) of different adhesives for orthodontic brackets in accordance with DIN 13990-1/-2, also taking into consideration potential effects arising from different scenarios of enamel conditioning and specimen storage. A total of 390 experiments were performed, with groups of 10 specimens subjected to identical treatments. Three adhesives were tested: Transbond™ XT (3M Unitek, Monrovia, USA), Beauty Ortho Bond (Shofu, Kyoto, Japan), and Fuji Ortho LC (GC Europe, Leuven, Belgium). SBS was evaluated separately at the bracket–adhesive and adhesive–enamel interfaces, as well as the total (enamel–adhesive–bracket) interface. The brackets were metal brackets for upper right central incisors (Discovery® from Dentaurum, Ispringen, Germany). A universal testing machine (Zwick Z010, Ulm, Germany) was used for testing the SBS after 15 min, or after storage in distilled water at 37 °C for 24 h, or after 24 h followed by 500 thermocycles alternating between 5 and 55 °C. Transbond™ XT produced the highest levels of SBS. The least favorable performance was observed with Fuji Ortho LC after enamel conditioning with 10 % polyacrylic acid. Thermocycling did not have a significant influence. Transbond™ XT and Beauty Ortho Bond (but not Fuji Ortho LC) yielded levels of SBS adequate for clinical application (≥ 7 MPa).

SUMMARY Intraoral repairs of ceramic fixed-dental-prostheses (FDP) often include cervical recessions that require pretreatment of the exposed tooth surfaces either before or after the ceramic is conditioned with hydrofluoric (HF) acid gel. The sequence of repair protocol may cross-contaminate the exposed etched enamel or dentin surfaces during the application or rinsing process and thereby affect the adhesion. This study evaluated the influence of HF acid gel with two concentrations on bond strengths of composite to enamel and dentin. Human third molars (N=100, n=10 per group) with similar sizes were selected and randomly divided into 10 groups. Flat surfaces of enamel and dentin were created by wet ground finishing. Before or after the enamel (E) or dentin (D) was conditioned with phosphoric acid (P), substrate surfaces were conditioned with either 9.5% HF (HF9.5) or 5% HF (HF5). Subsequently, a bonding agent (B) was applied. The experimental groups by conditioning sequence were as follows where the first letter of the group abbreviation represents the substrate (E or D) followed by the acid type and concentration: group 1 (EPHF9.5), group 2 (EPHF5), group 3 (EHF9.5P), group 4 (EHF5P), group 5 (DPHF9.5), group 6 (DPHF5), group 7 (DHF9.5P), and group 8 (DHF5P). Group 9 (EPB) and group 10 (DPB) acted as the control groups. Repair resin was adhered incrementally onto the conditioned enamel and dentin in polyethylene molds. Each layer was photo-polymerized for 40 seconds. All specimens were thermocycled (×1000, 5°-55°C) and subjected to shear test (universal testing machine, 1 mm/min). Specimens that debonded during thermocycling were considered as 0 MPa. The bond strength data were analyzed using Kruskal-Wallis test and failure types using the chi-square test (α=0.05). Overall, the bond results (MPa) were lower on dentin than on enamel (p

With the aid of an innovatively structured ceramic block, it is possible to achieve results at a high esthetic level with relatively simple means. In the three-dimensionally structured Vitablocs RealLife, translucent enamel ceramic is arranged around a conically structured, opaque dentin core. The virtual restoration can be positioned freely in all three dimensions with the aid of the Cerec/inLab software. The restorations are milled fully anatomically and only minimally glazed or characterized with stains. Results that otherwise can be achieved only with much more complex layering processes are possible.

Objective: Bracket bonding has been a major advance in orthodontic treatment. However, the method of debonding can lead to diverse problems such as enamel fractures, enamel loss and enamel scratching. In this clinical investigation we aimed to evaluate the influence of wearing dental loupes on enamel damage during the debonding procedure. Material and Methods: 22 consecutive patients were randomly assigned in a split-mouth study to evaluate adhesive removal with and without the use of dental loupes (2.5×, LED headlight). Tooth replicas in epoxy resin were made from silicone impressions. Electron microscopic images (50× magnification) of 394 buccal enamel surfaces were evaluated according to an enamel damage index (EDI), line angle grooves (LAG) and composite residues (CR) on anterior teeth, premolars and molars. Results: The EDI revealed highly significant advantages for debonding with dental loupes, with which the EDI was significantly higher for molars, while still less than without dental loupes. We detected no differences between the tooth groups without dental loupes. We found significantly fewer LAG on anterior teeth debonded with dental loupes. CR were fewer in the dental loupes group, and we noted no significant differences between the tooth groups. Conclusions: Dental loupes affect the quality of the debonding procedure, resulting in less enamel damage and composite residue, as well as fewer LAG compared to the control group. We therefore strongly recommend the use of dental loupes in orthodontic debonding procedures

The aim of this study was to examine whether brownish crown and root discoloration of wisdom teeth was related to treatment of acne with tetracyclines. For this purpose, 17 discolored third molars from nine patients were embedded without being decalcified, ground along the tooth axis, and examined using fluorescence microscopy. A thorough medical history served to determine the start and duration of any administration of tetracyclines. This confirmed the use of drugs against acne containing minocycline in all cases except one. The microscopic analyses of all teeth revealed intensely fluorescent bands in the dentin, which corresponded to the mineralization front at the time of tetracycline intake. More or less uniform discoloration of the entire crown was seen in association with treatment against acne prior to the completion of crown formation at the age of about 15 years. This uniform staining can be attributed to incorporation of minerals during ongoing maturation of the occlusal enamel, which is concomitant with the formation of the cervical crown regions. When acne was treated between 15 and 22 years of age, only the roots of the third molars displayed annular discolorations, which seemed to result from the incorporation of tetracyclines into dentin, while fine fluorescent incremental lines in root cementum were too thin to be apparent clinically. Three accidentally removed interradicular bony septa revealed that tetracyclines incorporated into alveolar bone remained there for about 2 years, but thereafter disappeared as a result of physiological remodelling.

Oral jewelry is popular. One of the most widely spread types are so-called tooth diamonds made of composite materials which are applied to the teeth with an adhesive. Note that parents are required to sign a release form for under-aged patients in Switzerland. Tooth cap grills and gold teeth are considered status symbols within the Hip-Hop fashion scene. However, tooth ornaments favour the accumulation of plaque and can diminish the ability to articulate. With respect to jewelry in oral soft tissue especially tongue and lip piercings are of significance to dentists. Besides the systemic complications, which are mostly caused by a lack of hygiene or the failure of noting medical contraindications by the piercer, local complications occur frequently. After surgery, pain, swelling, infections as well as hemorrhages or hematomas can be observed. Long-term effects can be problematic: gingival recession can be discernes mainly in the case of lip piercings the loss of hard tooth substance in the case of tongue piercings. Because of that, conservation therapies can become indespensable. Patients wearing dental jewelry have to be aware of risks of tooth damage, and they regularly have to undergo dental check-ups. Information campaigns--for dentists as well as patients--are necessary.

This in vitro study investigated the effects of exposure to modified (with respect to calcium phosphate saturation) solutions of a commercial available saliva substitute (Saliva natura) on mineralization of enamel in vitro.Bovine enamel specimens were prepared. Before and after demineralization (pH 4.95, 14 d, 37 degrees C), one-quarter of each specimen's surface was covered with nail varnish (control of sound/demineralized tissue). Specimens were exposed either to original Saliva natura [saturation with respect to octacalciumphosphate (S (OCP)): 0.03, pH 5.8] or to three lab-produced Saliva natura modifications (S (OCP): 1, 2, 3, pH 6.0) for two and five weeks (37 degrees C). An aqueous solution (S (OCP): 2.7, pH 7.0; Buskes remineralizing solution) served as positive control. Differences in mineral losses (DeltaDeltaZ) and lesion depths (DeltaLD) before and after storage were evaluated from microradiographs.After two weeks storage no differences among the solutions with regard to DeltaDeltaZ and DeltaDeltaLD could be observed (p0.05; ANOVA). Five weeks storage in original Saliva natura resulted in significantly lower DeltaDeltaZ values compared to all other solutions (p0.05). No differences with respect to DeltaDeltaZ among the modified solutions (S (OCP) 1, 2, 3; p0.05) could be observed, whereas storage in the remineralizing solution resulted in higher DeltaDeltaZ values compared to all other solutions (p0.05). For DeltaLD similar results could be revealed. However, no differences between the remineralizing solution and Saliva natura S (OCP) 2 could be shown (p0.05).Saliva natura with an S (OCP) of 2 showed the highest remineralizing capacities. More pronounced remineralization could not be achieved with a higher S (OCP) of 3 under the conditions chosen.

Dental products with casein phosphopeptide--amorphous calcium phosphate-nanocomplexes (CPP-ACP) are used in several tooth products (toothpastes, chewing gums, mouthrinses) and are as well used in dental filling material. CPP-ACP containing products are supposed to enhance remineralisation of dental hard tissues und thus might play a major role in prevention and therapy of initial caries or erosively dissolved enamel. Furthermore, also in hypersensitive teeth and even cases of hyposalivation, CPP-ACP containig products are supposed to improve the clinical condition. This article aims at three goals: point out the evolvement of CPP-ACP out of milk casein; description of possible biochemical effects of CPP-ACP on dental hard tissues; critical review of the current literature.

There are several questions with regard to the application and possible side effects of external bleaching therapies. The following short review gives answers to some questions regarding this topic. It might be concluded that every bleaching therapy should be preceded by a meticulous intraoral examination. To reduce the risk of adverse effects, it is mandatory to have knowledge about the mode of action of bleaching agents.