Digital impression techniques are advertised as an alternative to conventional impressioning. The purpose of this in vitro study was to compare the accuracy of full ceramic crowns obtained from intraoral scans with Lava C.O.S. (3M ESPE), CEREC (Sirona), and iTero (Straumann) with conventional impression techniques.A model of a simplified molar was fabricated. Ten 2-step and 10 single-step putty-wash impressions were taken using silicone impression material and poured with type IV plaster. For both techniques 10 crowns were made of two materials (Lava zirconia, Cera E cast crowns). Then, 10 digital impressions (Lava C.O.S.) were taken and Lava zirconia crowns manufactured, 10 full ceramic crowns were fabricated with CEREC (Empress CAD) and 10 full ceramic crowns were made with iTero (Copran Zr-i). The accessible marginal inaccuracy (AMI) and the internal fit (IF) were measured.For AMI, the following results were obtained (mean ± SD): overall groups, 44 ± 26 μm; single-step putty-wash impression (Lava zirconia), 33 ± 19 μm; single-step putty-wash impression (Cera-E), 38 ± 25 μm; two-step putty-wash impression (Lava zirconia), 60 ± 30 μm; two-step putty-wash impression (Cera-E), 68 ± 29 μm; Lava C.O.S., 48 ± 25 μm; CEREC, 30 ± 17 μm; and iTero, 41 ± 16 μm. With regard to IF, errors were assessed as follows (mean ± SD): overall groups, 49 ± 25 μm; single-step putty-wash impression (Lava zirconia), 36 ± 5 μm; single-step putty-wash impression (Cera-E), 44 ± 22 μm; two-step putty-wash impression (Lava zirconia), 35 ± 7 μm; two-step putty-wash impression (Cera-E), 56 ± 36 μm; Lava C.O.S., 29 ± 7 μm; CEREC, 88 ± 20 μm; and iTero, 50 ± 2 μm.Within the limitations of this in vitro study, it can be stated that digital impression systems allow the fabrication of fixed prosthetic restorations with similar accuracy as conventional impression methods.Digital impression techniques can be regarded as a clinical alternative to conventional impressions for fixed dental restorations.
The aim of our study was to measure and compare degree of conversion (DC) as well as micro- (indentation modulus, E; Vickers hardness, HV) and macromechanical properties (flexural strength, σ; flexural modulus, E flexural) of two recently launched bulk fill resin-based composites (RBCs): Surefil® SDR™ flow (SF) and Venus® bulk fill (VB).DC (n = 6) was investigated by Fourier transform infrared spectroscopy (FTIR) in clinical relevant filling depths (0.1, 2, and 4 mm; 6 mm bulk, 6 mm incremental) and irradiation times (10, 20, 40 s). Micro- (n = 6) and macromechanical (n = 20) properties were measured by an automatic microhardness indenter and a three-point bending test device after storing the specimens in distilled water for 24 h at 37°C. Furthermore, on the 6-mm bulk samples, the depth of cure was determined. A field emission scanning electron microscope was used to assess filler size. Results were evaluated using one-way analysis of variance, Tukey’s honest significance test post hoc test, a multivariate analysis (α = 0.05) and an independent t test. Weibull analysis was used to assess σ.VB showed, in all depth, significant higher DC (VB, 62.4–67.4 %; SF, 57.1–61.9 %), but significant lower macro- (VB, E flexural = 3.6 GPa; σ = 122.7 MPa; SF, E flexural = 5.0 GPa; σ = 131.8 MPa) and micromechanical properties (VB, E = 7.3–8.8 GPa, HV = 40.7–46.5 N/mm²; SF, E = 10.6–12.2 GPa, HV = 55.1–61.1 N/mm²). Both RBCs showed high reliability (VB, m = 21.6; SF, m = 26.7) and a depth of cure of at least 6 mm at all polymerization times. The factor “RBC” showed the strongest influence on the measured properties (η 2 = 0.35–0.80) followed by “measuring depth” (η 2 = 0.10–0.46) and “polymerization time” (η 2 = 0.03–0.12).Significant differences between both RBCs were found for DC, E, σ, and E flexural at all irradiation times and measuring depths.Curing the RBCs in 4-mm bulks for 20 s can be recommended.
The purpose of this prospective study was to evaluate the clinical outcome of anterior and posterior crowns made of a lithium-disilicate glass–ceramic framework material (IPS e.max Press, Ivoclar Vivadent).A total of 104 single crowns were placed in 41 patients (mean age, 34 ± 9.6 years; 15 male, 26 female). Eighty-two anterior and 22 posterior crowns were inserted. All teeth received a 1-mm-wide chamfer or rounded shoulder preparation with an occlusal/incisal reduction of 1.5–2.0 mm. The minimum framework thickness was 0.8 mm. Frameworks were laminated by a prototype of a veneering material combined with an experimental glaze. Considering the individual abutment preconditions, the examined crowns were either adhesively luted (69.2 %) or inserted with glass–ionomer cement (30.8 %). Follow-up appointments were performed 6 months after insertion, then annually. Replacement of a restoration was defined as failure.Four patients (10 crowns) were defined as dropouts. For the remaining 94 crowns, the mean observation time was 79.5 months (range, 34–109.7 months). The cumulative survival rate according to Kaplan–Meier was 97.4 % after 5 years and 94.8 % after 8 years. Applying log rank test, it was shown that the location of the crown did not significantly have an impact on the survival rate (p = 0.74) and that the cementation mode did not significantly influence the occurrence of complications (p = 0.17).The application of lithium-disilicate framework material for single crowns seems to be a reliable treatment option.Crowns made of a lithium-disilicate framework material can be used clinically in the anterior and posterior region irrespective of an adhesive or conventional cementation when considering abutment preconditions.
With direct and indirect digitalisation, two access points to CAD/CAM-generated restorations are available. The aim of this study was to compare the accuracy of the single steps of both approaches by comparing construction datasets using a new methodology.Twelve test datasets were generated in vitro (1) with the Lava Chairside Oral Scanner (COS) (2) by digitizing polyether impressions (IMP) and (3) by scanning the referring gypsum cast by the Lava Scan ST laboratory scanner (ST) at a time. Using an inspection software, these datasets were superimposed by a best fit algorithm with the reference dataset (REF), gained from industrial computed tomography, and divergences were analysed.On the basis of average positive and negative deviations between test- and REF datasets, it could be shown that direct digitalisation accomplished the most accurate results (COS, 17 μm/−13 μm; SD ± 19 μm), followed by digitized polyether impression (IMP, 23 μm/−22 μm; SD ± 31 μm) and indirect digitalisation (ST, 36 μm/−35 μm; SD ± 52 μm). The mean absolute values of Euclidean distances showed the least values for COS (15 μm; SD ± 6 μm), followed by IMP (23 μm; SD ± 9 μm) and ST (36 μm; SD ± 7 μm). The mean negative and mean absolute values of all groups were significantly different. Comparing the mean positive values of the groups, IMP and COS (p = 0.082) showed no significant difference, whereas ST and COS, and ST and IMP exhibited statistically significant differences.Within the limitations of this in vitro study, the direct digitalisation with Lava C.O.S. showed statistically significantly higher accuracy compared to the conventional procedure of impression taking and indirect digitalisation.Within the limitations of this study, the method of direct digitalisation seems to have the potential to improve the accuracy of impressions for four-unit FDPs.
The purpose of this review was to summarize recent developments regarding photodynamic therapy (PDT) in the field of dentistry.A review of pertinent literature was carried out in PubMED to determine the current position of PDT applications in dentistry. One hundred thirteen relevant articles were retrieved from PubMED by inserting the keywords “photodynamic therapy”, “dentistry”, “periodontology”, “oral surgery”, and “endodontics”. It is anticipated that this overview will create a specific picture in the practitioner’s mind regarding the current status and use of PDT.In spite of different results and suggestions brought about by different researchers, PDT can be considered as a promising and less invasive technique in dentistry.PDT seems to be an effective tool in the treatment of localized and superficial infections. Within the limitations of the present review, it can be concluded that although PDT cannot replace antimicrobial therapy at its current stage, it may be used as an adjunctive tool for facilitating the treatment of oral infections.Oral infections (such as mucosal and endodontic infections, periodontal diseases, caries, and peri-implantitis) are among the specific targets where PDT can be applied. Further long-term clinical studies are necessary in establishing a more specific place of the technique in the field of dentistry.
The purpose of the study was to compare the accuracy of crowns exclusively fabricated by the digital workflow of two systems. The null hypothesis stated was: Both systems do not differ with respect to marginal and internal accuracy.In 14 patients, 13 molars and 1 premolar were prepared. Each preparation was scanned intraorally with two different digital impression systems, Lava COS and Cerec AC. On the basis of these data, Lava DVS crowns [DVS] and Vita Rapid Layering Technique crowns [RLT] were fabricated, respectively. Both systems contained of a zirconia framework and a digitally fabricated silicate ceramic veneering. The marginal and internal fit of the crowns was documented by a replica technique. The replicas were examined under microscope with a magnification of ×200. The Wilcoxon signed rank test was applied in order to test if the values of the two systems showed significant differences at p ≤ 0.05.The results were as follows in micrometers (±standard deviation): at the marginal gap, 51 (±38) for [DVS] and 83 (±51) for [RLT]; mid-axial, 130 (±56) for [DVS] and 128 (±66) for [RLT]; axio-occlusal, 178 (±55) for [DVS] and 230 (±71) for [RLT]; and centro-occlusal, 181 (±41) for [DVS] and 297 (±76) for [RLT]. According to the Wilcoxon signed rank test, the results differed significantly at the marginal, axio-occlusal, and centro-occlusal gaps.The null hypothesis had to be rejected.The exclusively digital workflow on the basis of intraoral digital impressions delivered clinically satisfying results for single crowns with both systems.
The objective of this paper is to examine the effect of alveolar ridge preservation (ARP) compared to unassisted socket healing.Systematic review with electronic and hand search was performed. Randomised controlled trials (RCT), controlled clinical trials (CCT) and prospective cohort studies were eligible.Eight RCTs and six CCTs were identified. Clinical heterogeneity did not allow for meta-analysis. Average change in clinical alveolar ridge (AR) width varied between −1.0 and −3.5 ± 2.7 mm in ARP groups and between −2.5 and −4.6 ± 0.3 mm in the controls, resulting in statistically significantly smaller reduction in the ARP groups in five out of seven studies. Mean change in clinical AR height varied between +1.3 ± 2.0 and −0.7 ± 1.4 mm in the ARP groups and between −0.8 ± 1.6 and −3.6 ± 1.5 mm in the controls. Height reduction in the ARP groups was statistically significantly less in six out of eight studies. Histological analysis indicated various degrees of new bone formation in both groups. Some graft interfered with the healing. Two out of eight studies reported statistically significantly more trabecular bone formation in the ARP group. No superiority of one technique for ARP could be identified; however, in certain cases guided bone regeneration was most effective. Statistically, significantly less augmentation at implant placement was needed in the ARP group in three out of four studies. The strength of evidence was moderate to low.Post-extraction resorption of the AR might be limited, but cannot be eliminated by ARP, which at histological level does not always promote new bone formation. RCTs with unassisted socket healing and implant placement in the ARP studies are needed to support clinical decision making.This systematic review reports not only on the clinical and radiographic outcomes, but also evaluates the histological appearance of the socket, along with site specific factors, patient-reported outcomes, feasibility of implant placement and strength of evidence, which will facilitate the decision making process in the clinical practice.
The aim of the present study was to investigate different fluorescence-based, two-color viability assays for visualization and quantification of initial bacterial adherence and to establish reliable alternatives to the ethidium bromide staining procedure.Bacterial colonization was attained in situ on bovine enamel slabs (n = 6 subjects). Five different live/dead assays were investigated (fluorescein diacetate (FDA)/propidium iodide (PI), Syto 9/PI (BacLight®), FDA/Sytox red, Calcein acetoxymethyl (AM)/Sytox red, and carboxyfluorescein diacetate (CFDA)/Sytox red). After 120 min of oral exposure, analysis was performed with an epifluorescence microscope. Validation was carried out, using the colony-forming units for quantification and the transmission electron microscopy for visualization after staining.The average number of bacteria amounted to 2.9 ± 0.8 × 104 cm−2. Quantification with Syto 9/PI and Calcein AM/Sytox red yielded an almost equal distribution of cells (Syto 9/PI 45 % viable, 55 % avital; Calcein AM/Sytox red 52 % viable, 48 % avital). The live/dead ratio of CFDA/Sytox red and FDA/Sytox red was 3:2. An aberrant dispersal was recorded with FDA/PI (viable 34 %, avital 66 %). The TEM analysis indicated that all staining procedures affect the structural integrity of the bacterial cells considerably.The following live/dead assays are reliable techniques for differentiation of viable and avital adherent bacteria: BacLight, FDA/Sytox red, Calcein AM/Sytox red, and CFDA/Sytox red. These fluorescence-based techniques are applicable alternatives to toxic and instable conventional assays, such as the staining procedure based on ethidium bromide.Differentiation of viable and avital adherent bacteria offers the possibility for reliable evaluation of different mouth rinses, oral medication, and disinfections.
A multicentric randomized, 3-year prospective study was conducted to determine for how long Biodentine, a new biocompatible dentine substitute, can remain as a posterior restoration.First, Biodentine was compared to the composite Z100®, to evaluate whether and for how long it could be used as a posterior restoration according to selected United States Public Health Service (USPHS)’ criteria (mean ± SD). Second, when abrasion occurred, Biodentine was evaluated as a dentine substitute combined with Z100®.A total of 397 cases were included. This interim analysis was conducted on 212 cases that were seen for the 1-year recall. On the day of restoration placement, both materials obtained good scores for material handling, anatomic form (0.12 ± 0.33), marginal adaptation (0.01 ± 0.10) and interproximal contact (0.11 ± 0.39). During the follow-up, both materials scored well in surface roughness (≤1) without secondary decay and post-operative pain. Biodentine kept acceptable surface properties regarding anatomic form score (≤1), marginal adaptation score (≤2) and interproximal contact score (≤1) for up to 6 months after placement. Resistance to marginal discoloration was superior with Biodentine compared to Z100®. When Biodentine was retained as a dentine substitute after pulp vitality control, it was covered systematically with the composite Z100®. This procedure yielded restorations that were clinically sound and symptom free.Biodentine is able to restore posterior teeth for up to 6 months. When subsequently covered with Z100®, it is a convenient, efficient and well tolerated dentine substitute.Biodentine as a dentine substitute can be used under a composite for posterior restorations.
Stem cell-based therapies are considered to be a promising treatment method for several clinical conditions such as Alzheimer's disease, Parkinson's disease, spinal cord injury, and many others. However, the ideal stem cell type for stem cell-based therapy remains to be elucidated.Stem cells are present in a variety of tissues in the embryonic and adult human body. Both embryonic and adult stem cells have their advantages and disadvantages concerning the isolation method, ethical issues, or differentiation potential. The most described adult stem cell population is the mesenchymal stem cells due to their multi-lineage (trans)differentiation potential, high proliferative capacity, and promising therapeutic values. Recently, five different cell populations with mesenchymal stem cell characteristics were identified in dental tissues: dental pulp stem cells, stem cells from human exfoliated deciduous teeth, periodontal ligament stem cells, dental follicle precursor cells, and stem cells from apical papilla.Each dental stem cell population possesses specific characteristics and advantages which will be summarized in this review. Furthermore, the neural characteristics of dental pulp stem cells and their potential role in (peripheral) neural regeneration will be discussed.
This study investigated the effect of sintering temperatures on flexural strength, contrast ratio, and grain size of zirconia.Zirconia specimens (Ceramill ZI, Amann Girrbach) were prepared in partially sintered state. Subsequently, the specimens were randomly divided into nine groups and sintered with different final sintering temperatures: 1,300°C, 1,350°C, 1,400°C, 1,450°C, 1,500°C, 1,550°C, 1,600°C, 1,650°C, or 1,700°C with 120 min holding time. Three-point flexural strength (N = 198; n = 22 per group) was measured according to ISO 6872: 2008. The contrast ratio (N = 90; n = 10 per group) was measured according to ISO 2471: 2008. Grain sizes and microstructure of different groups were investigated (N = 9, n = 1 per group) with scanning electron microscope. Data were analyzed using one-way ANOVA with Scheffé test and Weibull statistics (p < 0.05). Pearson correlation coefficient was calculated between either flexural strength or contrast ratio and sintering temperatures.The highest flexural strength was observed in groups sintered between 1,400°C and 1,550°C. The highest Weibull moduli were obtained for zirconia sintered at 1,400°C and the lowest at 1,700°C. The contrast ratio and the grain size were higher with the higher sintering temperature. The microstructure of the specimens sintered above 1,650°C exhibited defects. Sintering temperatures showed a significant negative correlation with both the flexural strength (r = −0.313, p < 0.001) and the contrast ratio values (r = −0.96, p < 0.001).The results of this study showed that the increase in sintering temperature increased the contrast ratio, but led to a negative impact on the flexural strength.Considering the flexural strength values and Weibull moduli, the sintering temperature for the zirconia tested in this study should not exceed 1,550°C.
The paper’s aim is to review dentin hypersensitivity (DHS), discussing pain mechanisms and aetiology.Literature was reviewed using search engines with MESH terms, DH pain mechanisms and aetiology (including abrasion, erosion and periodontal disease).The many hypotheses proposed for DHS attest to our lack of knowledge in understanding neurophysiologic mechanisms, the most widely accepted being the hydrodynamic theory. Dentin tubules must be patent from the oral environment to the pulp. Dentin exposure, usually at the cervical margin, is due to a variety of processes involving gingival recession or loss of enamel, predisposing factors being periodontal disease and treatment, limited alveolar bone, thin biotype, erosion and abrasion.The current pain mechanism of DHS is thought to be the hydrodynamic theory. The initiation and progression of DHS are influenced by characteristics of the teeth and periodontium as well as the oral environment and external influences. Risk factors are numerous often acting synergistically and always influenced by individual susceptibility.Whilst the pain mechanism of DHS is not well understood, clinicians need to be mindful of the aetiology and risk factors in order to manage patients’ pain and expectations and prevent further dentin exposure with subsequent sensitivity.
The objective of this prospective clinical study was to evaluate the performance of chair-side generated crowns after 48 months.Forty-one posterior full contour crowns made of a machinable lithium disilicate ceramic (e.max CAD LT) were inserted in 34 patients applying a chair-side CAD/CAM technique. One crown per patient was randomly selected for evaluation at baseline, after 6, 12, 24, 36, and 48 months according to modified US Public Health Service criteria.After a mean observation time of 51 months (min, 48 months; max, 56 months; SD ± 2.3 months), 29 crowns were available for re-examination. Within the observation period, one failure occurred due to a crown fracture after 2.8 years. Four abutment teeth revealed signs of biological complications: Two abutment changed sensibility perception from positive to negative within the first 13 month. Two abutment teeth showed secondary caries below the crown margin, one after the 24, and another after the 48 month recall. Both abutments received cervical adhesive composite fillings. The failure-free rate was 96.3 % after 4 years according to Kaplan–Meier (CI: upper bound, 4.4 years; lower bound, 4.7 years).Due to the fact that the secondary caries was not caused as a result of an inaccuracy of the crown margins and the endodontic complications were in a normal range, the clinical performance of the crowns was completely satisfying.The chair-side application of lithium disilicate crowns can be recommended.
The aim of this study was to demonstrate that the periodontal pathogen Aggregatibacter actinomycetemcomitans (AA) can be killed by irradiation with blue light derived from a LED light-curing unit due to its endogenous photosensitizers.Planktonic cultures of AA and Escherichia coli were irradiated with blue light from a bluephase® C8 light-curing unit with an emission peak at 460 nm, which is usually applied for polymerization of dental resins. A CFU-assay was performed for the analysis of viable bacteria after treatment. Moreover, bacterial cells were lysed and the lysed AA and E. coli were investigated for generation of singlet oxygen. Spectroscopic measurements of lysed AA and E. coli were performed and analyzed for characteristic absorption and emission peaks.A light dose of 150 J/cm2 induced a reduction of ≥5 log10 steps of viable AA, whereas no effect of blue light was found against E. coli. Spectrally resolved measurements of singlet oxygen luminescence showed clearly that a singlet oxygen signal is generated from lysed AA upon excitation at 460 nm. Spectroscopic measurements of lysed AA exhibited characteristic absorption and emission peaks similar to those of known porphyrins and flavins. AA can be inactivated by irradiation with blue light only, without application of an exogenous photosensitizer.These results encourage further studies on the potential use of these blue light-mediated auto-photosensitization processes in the treatment of periodontitis for the successful inactivation of Aggregatibacter actinomycetemcomitans.
In contrast to the well-established caries epidemiology, data on dentin hypersensitivity seem to be scarce and contradictory. This review evaluates the available literature on dentin hypersensitivity and assesses its prevalence, distribution, and potential changes.The systematic search was performed to identify and select relevant publications with several key words in electronic databases. In addition, the articles’ bibliographies were consulted.Prevalence rates range from 3 to 98 %. This vast range can be explained partly by the differences in the selection criteria for the study sample and also the variety in diagnostic approaches or time frames. Women are slightly more affected than men and an age peak of 30–40 years has been reported. Still, the prevalence of erosions with dentin exposure seems to increase in younger adults, often resulting in hypersensitivity. In older patients, root surfaces are frequently exposed due to periodontal disease which is associated with a high rate of dentin hypersensitivity, especially after periodontal treatment and intensified brushing activity. On the other hand, the number of affected seniors with tooth loss or even edentulism is reduced. About 25–30 % of the adult population report dentin hypersensitivity. Most dentists also consider it to be a relevant problem in their practice, but they request more information on this topic. Maxillary teeth are affected to a higher extent, but the different teeth show very similar rates. Buccal surfaces clearly show the highest prevalence rates.In spite of the advances regarding management of dentin hypersensitivity, it still remains an epidemiologically understudied field.Although great variations have been observed in the prevalence of dentin hypersensitivity, this issue is often observed by dentists and related by patients. However, further studies are necessary to find the cause of this condition and refine its management.
The aim of this study is to assess by means of shear bond strength tests (SBS), microleakage analysis (μLKG), and scanning electron microscopy (SEM) the bonding potential and sealing ability of a new self-adhering composite resin.SBS and μLKG of Vertise Flow (VF, Kerr) were measured and compared to the all-in-one adhesive systems G-Bond (GB, GC), AdheSE One (AO, Ivoclar Vivadent), Adper Easy Bond (EB, 3M ESPE), Xeno V (XV, Dentsply), and iBOND (iB, Heraeus Kulzer). For each system, 20 molars were tested for SBS on dentin (n = 10) and enamel (n = 10). For μLKG assessment, 12 premolars per group were selected and small, box-shaped cavities were made. After restoration, the teeth were immersed in 50 wt% silver nitrate solution for 24 h. For each group, 10 randomly selected specimens were processed for leakage calculations, while two of the specimens were examined under SEM. Between-group differences in SBS to dentin and μLKG were assessed using Kruskal–Wallis analysis of variance followed by the Dunn’s Multiple Range test. Enamel SBS data were analyzed with one-way ANOVA, followed by the Tukey test.On dentin and enamel, VF recorded the lowest SBS values that were statistically comparable to those measured by GB, iB, and AO. μLKG analysis showed the lowest percentage of stained interface for VF. Significantly greater extent of infiltration was seen for iB and EB.Although VF resulted in lower bond strengths values on either dental substrate, better marginal sealing ability was visualized in comparison with all-in-one adhesive systems.The results of the present study demonstrated satisfactory in vitro outcome of the self-adhering flowable composite resin VF when used to restore class I cavities.
The objectives were to bring light on fluoride to control dentin hypersensitivity (DHS) and prevent root caries.Search strategy included papers mainly published in PubMed, Medline from October 2000 to October 2011.Fluoride toothpaste shows a fair effect on sensitive teeth when combined with dentin fluid-obstructing agents such as different metal ions, potassium, and oxalates. Fluoride in solution, gel, and varnish give an instant and long-term relief of dentin and bleaching hypersensitivity. Combined with laser technology, a limited additional positive effect is achieved. Prevention of root caries is favored by toothpaste with 5,000 ppm F and by fluoride rinsing with 0.025–0.1 % F solutions, as the application of fluoride gel or fluoride varnish three to four times a year. Fluoride measures with tablets, chewing gum, toothpick, and flossing may be questioned because of unfavorable cost effectiveness ratio.Most fluoride preparations in combination with dentin fluid obstruction agents are beneficial to reduce DHS. Prevention of root caries is favorable with higher fluoride concentrations in, e.g., toothpaste.Fluoride is an effective agent to control DHS and to prevent root caries particularly when used in higher concentrations.
This study aimed to assess possible dental side effects associated with long-term use of an adjustable oral appliance compared with continuous positive airway pressure (CPAP) in patients with the obstructive sleep apnea syndrome and to study the relationship between these possible side effects and the degree of mandibular protrusion associated with oral appliance therapy. As part of a previously conducted RCT, 51 patients were randomized to oral appliance therapy and 52 patients to CPAP therapy. At baseline and after a 2-year follow-up, dental plaster study models in full occlusion were obtained which were thereupon analyzed with respect to relevant variables. Long-term use of an oral appliance resulted in small but significant dental changes compared with CPAP. In the oral appliance group, overbite and overjet decreased 1.2 (+/- 1.1) mm and 1.5 (+/- 1.5) mm, respectively. Furthermore, we found a significantly larger anterior-posterior change in the occlusion (-1.3 +/- 1.5 mm) in the oral appliance group compared to the CPAP group (-0.1 +/- 0.6 mm). Moreover, both groups showed a significant decrease in number of occlusal contact points in the (pre)molar region. Linear regression analysis revealed that the decrease in overbite was associated with the mean mandibular protrusion during follow-up [regression coefficient (beta) = -0.02, 95 % confidence interval (-0.04 to -0.00)]. Oral appliance therapy should be considered as a lifelong treatment, and there is a risk of dental side effects to occur. Patients treated with the oral appliance need a thorough follow-up by a dentist or dental-specialist experienced in the field of dental sleep medicine.
To analyze whether the contamination with a caries infiltrant system impairs the adhesive performance of etch-and-rinse and self-etching adhesives on dentin.Dentin contamination with the caries infiltrant system (Icon, DMG) was simulated by applying either hydrochloric acid (15 % HCl, Icon Etch, 15 s), the resin infiltrant (Icon infiltrant, 4 min), or both prior to the application of the respective adhesives (each group n = 10). In the control groups, the etch-and-rinse adhesive (Optibond FL, Kerr) and the self-etching adhesive (iBOND Self Etch, Hereaus) were applied without former contamination with the infiltrant system. Additionally, the adhesive performance of the resin infiltrant alone was tested. Shear bond strength of a nano-hybrid composite was analyzed after thermocycling (5,000×, 5–55°C) of the specimens and analyzed by ANOVA/Scheffé post hoc tests (p < 0.05) and Weibull statistics. Failure mode was inspected under a stereomicroscope at × 25 magnification.Contamination with the resin infiltrant alone did not impair shear bond strength, while contamination with hydrochloric acid or with hydrochloric acid and the resin infiltrant reduced shear bond strength (MPa) of the adhesives (Optibond FL: 20.5 ± 3.6, iBOND Self Etch: 17.9 ± 2.6) significantly. Hydrochloric acid contamination increased the number of adhesive failures. The adhesive performance of the caries infiltrant system alone was insufficient.The contamination with the caries infiltrant system impaired the shear bond strength of conventional dental adhesives.Contamination of the caries infiltrant system on dentin should be avoided due to the detrimental effect of hydrochloric acid etching.
OBJECTIVES: This study aimed to test the hypothesis that there is no difference in the survival rates of molars treated according to the conventional restorative treatment (CRT) using amalgam, atraumatic restorative treatment (ART) using high-viscosity glass ionomer, and ultraconservative treatment (UCT) protocol after 3.5 years. MATERIALS AND METHODS: Cavitated primary molars were treated according to CRT, ART, and UCT (small cavities were restored with ART and medium/large cavities were daily cleaned with toothpaste/toothbrush under supervision). Molar extractions resulting from toothache, sepsis, or pulp exposure were failures. The Kaplan-Meier method was used to estimate the survival curves. RESULTS: The numbers of treated teeth, among the 302 6-7-year-old children, were 341 (CRT), 244 (ART), and 281 (for UCT group: 109 small ART, 166 open cavities, and 6 combinations). Protocol groups were similar at baseline regarding gender and mean decayed missing filled tooth score, but not regarding age and type of surface. The numbers of molars extracted were 22 (CRT), 16 (ART), and 26 (UCT). Fistulae were most often recorded. After 3.5 years, the cumulative survival rate +/- standard error for all molars treated was 90.9 +/- 2.0 % with CRT, 90.4 +/- 2.4 % with ART, and 88.6 +/- 1.9 % with UCT (p = 0.13). Only a type of surface effect was observed over the 3.5-year period: survival rates for molars were higher for single- than for multiple-surface cavities. CONCLUSION: There was no difference in the cumulative survival rates of primary molars treated according to the CRT, ART, and UCT protocols over a 3.5-year period. CLINICAL RELEVANCE: Keeping cavities in primary molars biofilm-free might be another treatment option alongside restoring such cavities through conventional and ART protocols.