Showing papers in "Clinical Oral Investigations in 2005"
TL;DR: Rating scales were developed for several factors that were considered relevant to the problem of clinically evaluating dental restorative materials, and criteria were adopted when field testing indicated that examiners were able to duplicate their own judgments and judgments of other examiners at a predetermined level of acceptability.
Abstract: Rating scales were developed for several factors that were considered relevant to the problem of clinically evaluating dental restorative materials. Examiners were trained to use the rating scales, and their performance was evaluated in field trials. Data analysis of examiner performance was used to revise the written criteria, and to train the examiners in making consistent judgments of dental restorations. Criteria were adopted when field testing indicated that examiners were able to duplicate their own judgments and judgments of other examiners at a predetermined level of acceptability. Further experience with the rating scales in actual clinical studies led to the consolidation of anterior and posterior criteria, which had been developed separately, and to the deletion of certain rating scales which failed to yield useful information. The rating scales which were finally adopted are for color match, cavo-survace marginal discoloration, anatomic form, marginal adaptation, and caries.
312 citations
TL;DR: RelyX Unicem may be considered an alternative to Ketac Cem for high-strength ceramic or metal-based restorations, and may be used for luting conventional ceramic crowns with little or no enamel left.
Abstract: The objective of this study was to assess the bonding performance of a new universal self-adhesive cement RelyX Unicem (RXU) to dentin and enamel compared to four currently used luting systems, using a shear bond strength test with and without thermocycling. Median bond strengths were determined after 24 h storage, and after thermocycling (6,000 cycles, 5–55°C) for RXU and compared to Syntac/Variolink II (SynC/V) as a standard for luting conventional ceramics, ED-Primer II/Panavia F2.0 (EDII/PF2), Prime&Bond NT/Dyract Cem Plus (PBNT/DyCP), and a glass ionomer cement, Ketac Cem (KetC), as a standard for luting high-strength ceramic and metal-based restorations. Data (n=10 per group) were statistically analyzed using the Mann–Whitney–Wilcoxon test at the 0.05 level of significance. The bond strength (MPa) of RXU to dentin (10.8) was not statistically different from those of SynC/V (15.1), EDII/PF2 (10.5) or PBNT/DyCP (10.1), and statistically higher than KetC (4.1). The bond strength of RXU to enamel (14.5) was significantly lower than those of SynC/V (32.8), EDII/PF2 (23.6), and PBNT/DyCP (17.8), but higher than KetC (6.1). After thermocycling, the bond strength of RXU to enamel significantly decreased, but was still significantly higher than that of KetC. RelyX Unicem may be considered an alternative to Ketac Cem for high-strength ceramic or metal-based restorations, and may be used for luting conventional ceramic crowns with little or no enamel left.
211 citations
TL;DR: It may be concluded that Y seems to be most suitable for the removal of supragingival early plaque biofilms grown onSLA titanium implants, and all treatment procedures failed to restore the biocompatibility of previously-contaminated SLA titanium surfaces.
Abstract: The aim of the present study was to evaluate the influence of different treatment approaches on: (1) the removal of early plaque biofilms grown on titanium implants, and (2) the biocompatibility of the instrumented implant surfaces. Five volunteers wore acrylic splints with sand-blasted and acid-etched titanium discs for 24 h to build up supragingival plaque. A total of 80 specimens were randomly assigned to the following groups: (1) an Er:YAG laser (100 mJ/pulse, 10 Hz) (Y), (2) an ultrasonic system (U), (3) plastic curettes and rinsing with chlorhexidine digluconate (P), or (4) unworn titanium discs (C). Autoclaved specimens were incubated with SAOS2 cells for three days. The following parameters were measured: treatment time (T), residual plaque biofilm (RPB) and clean implant surface (CIS) areas (%), and mitochondrial cell activity (MA) (counts/s). Statistical analysis within and between groups revealed the following mean scores (±SD): RPB areas: P (61.1±11.4) > U (36.8±4.5) > Y (5.8±5.1); CIS areas: Y (94.2±5.1) > U (63.2±4.5) > P (38.9±11.2); T: Y (5.6±1.2) > U (2.4±0.5) > P (2.3±0.5); MA: C (1.528.636±188.371) > U (831.594±370.228) > Y (678.250±367.902) > P (144.105±120.961). Within the limits of the present study, it may be concluded that Y seems to be most suitable for the removal of supragingival early plaque biofilms grown on SLA titanium implants, and (2) all treatment procedures failed to restore the biocompatibility of previously-contaminated SLA titanium surfaces.
165 citations
TL;DR: The flowable derivatives are more cytotoxic than the traditional composites whereas the ormocer Admira Flow is less cytotoxicity than the AdMira composite.
Abstract: The release of components from dental composite into surrounding tissue may cause an adverse tissue reaction. Thus, this study investigated the cytotoxicity of three types of dental composites with their flowable derivatives and determined the compounds released from these materials by high-performance liquid chromatography (HPLC) analysis. Fifteen specimens from each composite (Admira, Z250, Tetric Ceram) with fifteen of their flowables (Admira Flow, Tetric Flow, Feltik Flow) were prepared in the form of discs and divided into two groups of 10 and 5 for each material. The first group (10 discs) was used to evaluate the cytotoxicity of the material on balb/c 3T3 fibroblasts by measuring cellular metabolic activity (3{4,5-dimethylthiazol-2-yl}-2,5-diphenyltetrazolium bromide [MTT] assay) relative to Teflon controls, while the second group (5 discs) was used to determine the leached components from each material into culture medium by HPLC analysis. The results revealed that Z250 and Tetric Ceram were less cytotoxic than their flowable derivatives. However, the ormocer, Admira, was significantly more cytotoxic than Admira Flow. Among the standard composites, Tetric Ceram was the least cytotoxic and Admira the most. Furthermore, Tetric flow was the most cytotoxic and Admira flow was significantly the least cytotoxic among the flowable materials tested. HPLC analysis revealed bisphenol A glycerolate dimethacrylate (bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) in the eluates of all the materials, while urethane dimethacrylate (UDMA) was present in all eluates except that of Feltik Flow. In conclusion, the flowable derivatives are more cytotoxic than the traditional composites whereas the ormocer Admira Flow is less cytotoxic than the Admira composite.
132 citations
TL;DR: This preface to the republication of the original article provides key background information and references to contributions by the many now-famous clinical investigators who were involved with pilot studies that led to the final USPHS guidelines.
Abstract: The original article published by Cvar and Ryge in 1971 on the US Public Health Service (USPHS) Guidelines is virtually inaccessible to current scientists, despite its remarkable impact on clinical dental research. The original article described all the pilot studies that led to the choices for the final USPHS guidelines. However, many of the important basic ideas expressed in the original article, such as evaluator calibration, have been overlooked in recent years. Challenges for effective clinical testing of restorative procedures and materials that were emphasized by those authors are even more relevant today. Therefore, it is totally appropriate to republish the original article by Cvar and Ryge in this issue of Clinical Oral Investigations. This preface to the republication of the original article provides key background information and references to contributions by the many now-famous clinical investigators who were involved with pilot studies. In addition, the USPHS recommendations are critically reviewed. Clinical evaluation of restorative procedures requires (a) choices of clinically relevant criteria, (b) assessment using simple nominal scales, (c) calibration of evaluators, (d) two independent evaluations, and (e) nonparametric statistic analysis that recognizes the patient (and not the restoration) as the independent variable. Only portions of those procedures are being preserved in current clinical investigations. USPHS criteria continue in use until today as part of routine clinical evaluation and as components of standards programs such as the ADA acceptance program. However, in addition, USPHS-like criteria have been appended over the years to produce “modified USPHS guidelines.” These additional criteria include parameters such as postoperative sensitivity, fracture, interproximal contact, occlusal contact, and others. The combination of the original and modified USPHS criteria now have been accepted worldwide but are not necessarily uniformly applied. They constitute the foundation for current considerations of further development of clinical assessment methods for dental restorative procedures.
122 citations
TL;DR: The results indicate that dental plaque in patients with chronic lung diseases often serves as a reservoir of bacteria known to cause nosocomial pneumonia in susceptible individuals.
Abstract: Bacterial cultivation studies have shown that dental plaque is a reservoir for respiratory pathogens in intensive care unit patients and in elderly who are debilitated, hospitalized or in a nursing home, placing them at risk of bacterial pneumonia. No information is available, however, concerning dental plaque as a reservoir of putative respiratory pathogens in hospitalized patients with chronic lung diseases. Supragingival plaque colonization of 34 hospitalized chronic lung-diseased Romanian citizens, excluding those with tuberculosis and less than 20 teeth, was therefore assessed by checkerboard DNA–DNA hybridization using a selected panel of whole genomic DNA probes produced from eight respiratory pathogens and eight oral pathogens. Thirty-one lung-healthy dental outpatients served as reference population. Respiratory pathogens were detected in plaque from 29 of the 34 (85.3%) hospitalized patients and 12 of the 31 (38.7%) reference population subjects. Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacter cloacae occurred significantly (p<0.05) more frequent among the hospitalized patients. Hospitalized chronic lung-diseased patients harbored in their supragingival plaque samples bacteria known to cause nosocomial pneumonia significantly (p<0.001) more frequent than lung-healthy dental outpatients. Our results indicate that dental plaque in patients with chronic lung diseases often serves as a reservoir of bacteria known to cause nosocomial pneumonia in susceptible individuals.
110 citations
TL;DR: The in vitro study evaluated the whitening effect of different external bleaching agents on enamel-dentin slabs and subsurface dentin and indicated that color change of treated teeth might be highly influenced by color changes of the subsurfaced dentin.
Abstract: Previous studies have shown that bleaching treatment may be efficient in both enamel and dentin, but it is still unknown how much the subsurface dentin contributes to the color change of teeth. This in vitro study evaluated the whitening effect of different external bleaching agents on enamel-dentin slabs and subsurface dentin. Ninety bovine teeth were distributed among six groups (A, Opalescence 10%; B, Opalescence PF 15%; C, Opalescence Quick; D, Opalescence Extra Boost; E, Rapid White; F, Whitestrips). Two enamel-dentin specimens were prepared from the labial surface of each teeth. In one of the specimens enamel was removed, resulting in a dentin (CD) disc of 1 mm high. The labial and the pulpal sides of the second specimen were ground until the remaining enamel and dentin layers of the enamel-dentin sample (ED) were 1 mm each. Whitening treatment of the ED specimens was performed according to manufacturers’ instructions. Pre- and posttreatment Lab values of ED samples were analyzed using CIE-Lab. Baseline Lab values of dentin were analyzed by evaluation of the CD specimen. Finally, enamel of the ED specimens was removed and color change of the exposed dentin (D) was recorded. For all treatment agents significant color changes (ΔE) were observed for enamel-dentin samples and subsurface dentin specimens compared to controls. In groups A–D ΔE was significantly higher in dentin than enamel-dentin. Furthermore, L and b values of bleached enamel-dentin and subsurface dentin samples differed significantly from baseline. Treatment with the tested external whitening bleaching agents resulted in color change of both enamel-dentin and subsurface dentin samples. The results indicate that color change of treated teeth might be highly influenced by color change of the subsurface dentin.
100 citations
TL;DR: The aim of this study was to evaluate the performance of shade-determining devices and it becomes evident that the methods—especially the computer-aided shade determination—are rather divided about the respective tooth color.
Abstract: The aim of this study was to evaluate the performance of shade-determining devices. For the daily practitioner, it is essential to know whether modern computer-aided shade selection is reliable in everyday life. So the question of how the clinical usability of these machines could be rated has to be clarified. In the following, three actual devices available in the market were compared using a human observer's perception. The SpectroShade device (MHT Optic Research AG, 8155 Niederhasli, Switzerland), the ShadeVision device (X-Rite Co., Grandville, USA) and the Digital Shade Guide DSG4 (A. Rieth, 73614 Schorndorf, Germany) were assessed with respect to their agreement with the color perception of three examiners looking at 57 test persons (six teeth each for a total of 342). Shades were reported in Vita Classical shades. It could be demonstrated that every single human examiner showed a significantly higher agreement value (human group on average 40.2%) when compared with the remaining five methods than each computer-aided tooth shade determination device. The devices reached on average only a value of 28.6%, whereas the X-Rite ShadeVision showed a significant better result (33.2%) than the MHT SpectroShade and Rieth DSG4 (27.0 and 25.7%). Identical shade results given by all three methods of a group (group of three devices and three humans) were found to be rather low for the computer-aided devices (9.9%) compared with humans (36.7%). All six methods together agreed in 3.3% of the cases. It becomes evident that the methods-especially the computer-aided shade determination-are rather divided about the respective tooth color. Deficiencies of the instrumental as well as the visual detection become obvious. The best agreement level was performed by the human examiners. The best agreement of the evaluated devices was obtained-generally as well as among the human testers-by the X-Rite ShadeVision system, followed at a statistically significant distance by the MHT SpectroShade and the Rieth DSG4. The agreement among the examiner group was 52.9%, significantly better than that of each device compared to this group (31.3% on average). Color detection and its realization are very complex. As shown, in many cases, computer-aided color shade determination of natural teeth seems to not reflect human perception.
96 citations
TL;DR: It seems that for the resin composite tested, the recommended exposure time of 40 s per 2-mm increment may be reduced to 20 s, or that increments may be increased from 2 to 3.5 mm.
Abstract: This in vitro study compared the depth of cure obtained with six quartz tungsten halogen and light-emitting diode curing units at different exposure times and light tip-resin composite distances. Resin composite specimens (Tetric Ceram, A3; diameter 4 mm, height 6 mm) were exposed from 0-, 3-, and 6-mm distance. The curing units (200–700 mW/cm2) were used for standard (20 and 40 s), pulse-delay mode (initial exposure of 3 s at 200 mW/cm2, followed by a resting period of 3 min and a final exposure of 10 or 30 s at 600 mW/cm2), or soft-start curing (40 s; exponential ramping). Curing depth was determined by measurement of Wallace hardness for each half millimeter starting at 0.5 mm from the top surface. For each specimen, a mean HW value was calculated from the HW values determined at the depths of 2.0 mm and less (0.5, 1.0, 1.5, and 2.0 mm, respectively). The depth of cure for each specimen was found by determining the greatest depth before an HW value exceeding the minimal HW value by 25% occurred. For all curing units, an increase in exposure time led to significantly higher depth of cure. Increasing the light tip-resin composite distance significantly reduced the depth of cure. With a light tip-resin composite distance of 6 mm, median values of depth of cure varied between 2.0 and 3.5 mm following a 20-s (or 3+10 s) exposure and between 3.0 and 4.5 mm following a 40-s (or 3+30 s) exposure. The composite situated above the depth of cure value cured equally well with all curing units. At both exposure times, Luxomax resulted in the significantly lowest depth of cure, and Astralis 7 yielded significantly higher depth. At both exposure times, a significant linear correlation was found between the determined power densities of the curing units and the pooled depth of cure values obtained. It seems that for the resin composite tested, the recommended exposure time of 40 s per 2-mm increment may be reduced to 20 s, or that increments may be increased from 2 to 3.5 mm. It may be that the absolute values of depth of cure found are material specific, but we believe that the relationships found between curing units, between exposure times, and between light guide distances are universal.
90 citations
TL;DR: The results show the potential of sealants to act as a noninvasive treatment of early approximal enamel lesions to arrest the progression of noncavitated approximal posterior carious lesions.
Abstract: The objective was to evaluate the clinical performance of a therapeutic sealant to arrest the progression of noncavitated approximal posterior carious lesions. The study population comprised 50 adolescents in whom bitewing radiographs had been taken for diagnosis of caries. Approximal noncavitated lesions in premolars and molars (4d–7m) were selected. One group (n=17) had a sealant placed after tooth separation on all enamel lesions. A second group (n=7) received sealant and fluoride varnish in a split-mouth design. A control group (n=26) received a standard fluoride varnish treatment without tooth separation. Follow-up radiographs were taken after 2 years and were analyzed together with the baseline radiographs in a blind study setting. About 93% of the sealed initial carious lesions showed no progression. The corresponding value for the fluoride varnish control group was 88%. In the split-mouth study, 92 and 88% of the surfaces with enamel caries showed no progression after sealant or fluoride varnish treatment, respectively. The difference between the two treatment procedures was not statistically significant. The incidence rate for the transition from enamel caries to dentin caries or fillings was 3.5–3.9 surfaces/100 years in the sealant groups and 5.9–6.1 surfaces/100 years in the fluoride varnish groups. The results show the potential of sealants to act as a noninvasive treatment of early approximal enamel lesions.
78 citations
TL;DR: Surface treatment of posts significantly increased the resistance to cyclic loading compared with untreated posts, and when posts are used, surface treatment is recommended.
Abstract: This in vitro study evaluated the effect of presence of post, presence of core, and of shape, type, and surface treatment of posts on resistance to cyclic loading of crowned human teeth. For all teeth, crowns designed without ferrule were cast in sterling silver and luted with resin cement (Panavia F). Each tooth underwent cyclic loading of 600 N at two loads per second until failure. Teeth that had only been crowned showed significantly higher resistance to cyclic loading than teeth with cores or with post and cores. No significant differences were found between teeth restored with cores only or with post and cores, irrespective of surface-treatment of the posts. Teeth restored with parallel-sided cast post (ParaPost XP) and cores showed significantly higher resistance to cyclic loading than teeth with either tapered cast posts or untreated prefabricated posts of titanium alloy (ParaPost XH) or glass fiber composite (ParaPost Fiber White). No significant difference was found between teeth restored with parallel-sided cast post and cores and teeth restored with untreated prefabricated posts of zirconia (Cerapost). Surface treatment of posts significantly increased the resistance to cyclic loading compared with untreated posts. When posts are used, surface treatment is recommended.
TL;DR: It was concluded that in the oral environment, polyethylene FRC promotes plaque accumulation and adhesion of MS more than glass FRC, restorative composite and dental ceramic.
Abstract: In the present study, two different fibre-reinforced composites (FRCs) (glass and polyethylene FRC), dental ceramic and restorative composite were compared with respect to early plaque formation in vivo. Disc-shaped specimens were randomly distributed among the upper first and second molars of 14 healthy adult volunteers. Plaque samples were collected 24 h after the attachment of the specimens. Mutans streptococci (MS), non-mutans streptococci and total facultative bacteria were cultured. The plaque recovered from polyethylene FRC harboured significantly more MS than the plaque of ceramic, restorative composite and glass FRC. For the counts of non-mutans streptococci and total facultative bacteria, polyethylene FRC showed the highest counts, and ceramic showed a trend towards lower counts. The amount of plaque accumulation showed an association to the earlier reported surface roughness values of the studied materials. It was concluded that in the oral environment, polyethylene FRC promotes plaque accumulation and adhesion of MS more than glass FRC, restorative composite and dental ceramic. Glass FRC resembles restorative composite with respect to plaque accumulation and the adherence of MS.
TL;DR: This first investigation in a population of Athens revealed a change in the eruption sequence of permanent teeth, relevant for dental treatment planning and should be reconfirmed at certain intervals.
Abstract: In a study in Athens, Greece, during the summer of 2003, 2,304 patients (1,168 boys and 1,176 girls) were examined by a young dentistry. The examination occurred within the framework of a routine dental check-up performed at the National and Kapodistrian University of Athens. The age span ranged from 3.00 to 24.93 years of age. Sex, age and present permanent teeth were recorded. Wisdom teeth were excluded. The sequence of tooth eruption differs significantly in the lower and upper jaw, whereas no significant differences existed when comparing the sides of each jaw. The tooth eruption in the lower and upper jaw of male and female probands is symmetrical. In comparing the upper and the lower jaw of both genders, it becomes evident that there is a tendency for earlier tooth eruptions in the lower jaw. In respect to the tooth eruption sequence, a change was noted in the upper jaw. Contrary to the reports of other authors, the second premolar has changed places with the canine and erupts prior to this tooth. This could also be demonstrated in recent studies from New York and Bremen (Germany). Otherwise no major differences concerning the sequence of tooth eruptions were observed, when compared with the results gained from other populations. Concerning the entire dentition, no acceleration of the tooth eruption could be noted. The computed differences of teeth eruption as a mean value calculated over all teeth was ±1 year at maximum, compared with studies from different continents. Oral examination of teeth is a simple tool to calculate tooth eruption intervals. This first investigation in a population of Athens revealed a change in the eruption sequence of permanent teeth. These findings are relevant for dental treatment planning and should be reconfirmed at certain intervals.
TL;DR: Electrophoretical analysis of recovered pellicle fractions indicate that combination of sponge-rubbing followed by EDTA treatment can be recommended for stepwise removal of the globular and basal pellicles layers from the enamel surface.
Abstract: The in vivo formed salivary pellicle is composed of an outer globular and a densely structured basal layer This study developed a method for selective recovering of these pellicle layers from the enamel surface Two-hour in situ pellicles were formed by intraoral exposure of enamel specimens in two adults Pellicle-covered enamel specimens were treated either mechanically (scraping with scaler, curette or razor blade, or rubbing with a sponge) or chemically (phosphate buffer, NaCl, NaOCl, CaCl2, NaSCN, urea, tetrahydrofurane, guanidine, SDS, HCl, or EDTA with or without additional ultrasonication) Specimens were processed for transmission electron microscopic analysis to detect pellicle residues remaining on the enamel surface after the different treatments Most of the chemical treatments caused partial, incomplete removal of the globular layer Complete removal of the globular layer without disruption of the basal layer was obtained by sponge rubbing or by CaCl2 combined with ultrasonication, whereas scraping caused partial disruption of the basal layer Removal of the basal layer was observed after treatment with HCl, EDTA, or NaOCl combined with ultrasonication Electrophoretical analysis of recovered pellicle fractions indicate that combination of sponge-rubbing followed by EDTA treatment can be recommended for stepwise removal of the globular and basal pellicle layers
TL;DR: The data suggest that the Down syndrome persons present a better buffer capacity, supporting the results observed in several studies which found the low dental caries in persons with Down syndrome.
Abstract: This study measured the flow rate, pH, and buffer capacity of saliva from children with Down syndrome aged 2–60 months. We compared 25 children with Down syndrome with 21 children without Down syndrome. The whole saliva was collected under slight suction and the pH and the buffer capacity were determined using a digital pHmeter. The buffer capacity was measured by titration with 0.01 N HCl. The Down syndrome group demonstrated higher buffer capacity than the control group in the pH ranges of 6.9–6.0, 5.9–5.0, and 4.9–4.0. The flow rate was low in the Down syndrome group. Boys from the Down syndrome group demonstrated higher buffer capacity in the pH ranges 6.9–6.0, 5.9–5.0, and 4.9–4.0 than controls, while girls from the Down syndrome group showed no difference compared with controls. Girls with Down syndrome demonstrated significant difference only in the range of pHi–pH 7.0. Conclusion. These data suggest that the Down syndrome persons present a better buffer capacity, supporting the results observed in several studies which found the low dental caries in persons with Down syndrome.
TL;DR: It can be concluded that neither the use of flowable resin composite liner nor the curing mode used influenced the interfacial adaptation of class II resin composite restorations with and without a flowable liner.
Abstract: The aim of this study was to evaluate in vivo the interfacial adaptation of class II resin composite restorations with and without a flowable liner In 24 premolars scheduled to be extracted after 1 month, 48 box-shaped, enamel-bordered class II cavities were prepared and restored with a flowable liner (FRC, Tetric Flow/Tetric Ceram/Syntac Single-Component) or without (TRC), cured with three different curing modes: soft start and 500- or 700-mW/cm2 continuous irradiation Interfacial adaptation was evaluated by quantitative scanning electron microscopic analysis using replica method Gap-free adaptation in the cervical enamel (CE) was observed for FRC and TRC in 962 and 902%, for the dentin (D) in 636 and 649%, and for occlusal enamel (OE) in 997 and 995%, respectively The difference between the two restorations was not statistically significant (ns) Significant better adaptation was observed for OE than CE and D (p<001), and for CE than D (p<001) Gap-free adaptation with the soft-start and 500- and 700-mW/cm2 continuous-curing modes was observed for CE: 887%, 927%, 979% (ns); OE: 998%, 987%, 100% (ns); and D: 640%, 639%, and 646% (ns), respectively It can be concluded that neither the use of flowable resin composite liner nor the curing mode used influenced the interfacial adaptation
TL;DR: This study was performed to analyze treatment of fractures of the edentulous mandible and to discuss this method in relation to the mandibular height at the fracture site, and to consider the use of two miniplates or a combination with microplates to obtain stable fixation in severely atrophic mandibles.
Abstract: This study was performed to analyze treatment of fractures of the edentulous mandible and to discuss this method in relation to the mandibular height at the fracture site. Fifteen fracture sites in 11 patients with an edentulous mandible were retrospectively examined. These fractures were located: nine fractures in the mandibular body, three in the paramedian region, and three in the mandibular angle. Fractures in a mandible measuring more than 10 mm in the vertical height were treated with one miniplate. Fractures in an extremely atrophic mandible with 10 mm or less were treated using one or two miniplates, also using a modified Champy plate with 1.3 mm in thickness. A mandibular fracture with a height of 5 mm was treated with a combination of a microplate on the buccal side and a miniplate on the inferior border of the mandible with additional direct circumferential wiring. Oblique or splitting fractures were treated with direct circumferential wiring or a Herbert screw, at one fracture site each, respectively. Complications, including infection, fibrous union, nonunion and trismus, were not seen. In one patient, hypesthesia of the lower lip was, however, persistent 1 month after surgery. Miniplate osteosynthesis is the less invasive treatment, and it is suitable for fractures of the atrophic edentulous mandible, except for comminuted or defect fractures. To obtain stable fixation in severely atrophic mandibles, we need to consider the use of two miniplates or a combination with microplates.
TL;DR: Assessment of intra- and interassay coefficient of variation and lower limit of quantification revealed that depending on the acid used, the applied method is a reliable and suitable tool to detect and quantify minimal phosphate contents in small samples of acidic solutions that have the potential to cause erosive dental lesions.
Abstract: The study describes the suitability of a colorimetric method (malachite green procedure) for detection of minimal amounts of phosphate (7.3-29.1 micromol/L) in different acidic solutions (hydrochloric acid, oxalic acid, maleic acid, perchloric acid, tartaric acid, citric acid, lactic acid and acetic acid) adjusted to pH 2.0. A mixture of the respective phosphate concentrations with distilled water served as control. The experiments were run with ten repeats in series. Assessment of intra- and interassay coefficient of variation and lower limit of quantification revealed that depending on the acid used, the applied method is a reliable and suitable tool to detect and quantify minimal phosphate contents in small samples of acidic solutions that have the potential to cause erosive dental lesions.
TL;DR: It is concluded that differently concentrated acidulated sodium fluoride gels resulted in concentration-related significant uptake of fluoride in carious-like demineralised enamel, leading to a better dem ineralisation protection with increasing fluoride concentration in the gel.
Abstract: The objective of this study was to analyse fluoride uptake and microhardness alteration of carious-like demineralised enamel after application of differently concentrated acidulated sodium fluoride gels and to determine the effect of fluoridation on enamel resistance against subsequent demineralisation. Artificial caries-like lesions of bovine enamel specimens were treated with sodium fluoride gels of different concentration (group A: 1.25%, group B: 0.62%, group C: 0.31%, group D: 0.15%; n=20 each group) for 5 min and stored in artificial saliva for 24 h. This cycle was carried out three times. Subsequently, KOH-soluble and structurally bound fluoride (determined at depths of 30, 60, and 90 microm) were analysed. In the second part of the study, for each 12 enamel specimens surface microhardness was determined before and after demineralisation, after fluoridation with the differently concentrated gels A-D, and after a second demineralisation. With all groups uptake of KOH-soluble and structurally bound fluoride resulted in higher levels than baseline content. Statistical analysis revealed significant differences between fluoride uptake among the groups, with highest uptake for the 1.25% gel and lowest for the 0.15% gel. Moreover, with all gels highest uptake was observed in the outermost enamel layer (P<0.05). Microhardness values after second demineralisation increased with increased concentration of the applied sodium fluoride gel. Increasing concentration of the applied gel implies better protection of the enamel specimens against subsequent demineralisation (P<0.05). It is concluded that differently concentrated acidulated sodium fluoride gels resulted in concentration-related significant uptake of fluoride in carious-like demineralised enamel, leading to a better demineralisation protection with increasing fluoride concentration in the gel.
TL;DR: The SEM data indicate that, with adhesively bonded partial ceramic crowns, retentive preparation is not contraindicated and the choice of luting material is more relevant than the preparation design.
Abstract: This in vitro study examines the effects of three preparation designs and different luting agents on the marginal integrity of partial ceramic crowns. One hundred forty-four extracted human molars were prepared according to the following preparation designs: A. Coverage of functional cusps, B. Horizontal reduction of functional cusps and C. Complete reduction of functional cusps. Partial ceramic crowns (Vita Mark II, Cerec 3 System) were bonded to the cavities with: Variolink II/Excite (Vivadent), Panavia F/ED primer (Kuraray), Dyract/Prime and Bond NT (Detrey/Dentsply), and Fuji Plus/GC cavity conditioner (GC). The specimens were exposed to thermocycling and mechanical loading. Marginal adaptation was assessed on replicas using quantitative margin analysis in the scanning electron microscope (SEM). Significant differences were observed between the preparation designs in general. Coverage of functional cusps with preparation of butt joints and use of Variolink as luting material showed a tendency toward the lowest values for compromised adhesion, especially within the dentin. Significant differences could be determined between luting systems: resin-modified glass ionomer cement (RMGIC) caused fracture of the restorations and revealed higher values than all other luting materials for compromised adhesion at ceramic-luting agent and tooth-luting agent interfaces. The dentin-luting material interface, in general, showed higher percentages of compromised adhesion (38–100%) than enamel- and ceramic-luting material interfaces (0–30%). In conclusion, the SEM data indicate that, with adhesively bonded partial ceramic crowns, retentive preparation is not contraindicated and the choice of luting material is more relevant than the preparation design. Margins below the cemento-enamel junction reveal significant loss of adhesion in spite of adhesive luting techniques. The RMGIC cannot be recommended as a luting material for feldspathic partial ceramic crowns.
TL;DR: The results of GTR with bioabsorbable membranes in combination with Bio-Oss in the treatment of periodontal intrabony defects are basically stable on a long-term basis.
Abstract: The aim of this study was to report on the clinical and radiographic results 5 years following treatment of intrabony defects with guided tissue regeneration (GTR) in combination with deproteinized bovine bone (DBB) (Bio-Oss). Fifteen patients, with at least one intrabony periodontal defect with probing pocket depth (PPD)≥7 mm and radiographic presence of an intrabony component (IC)≥4 mm, were treated with a PLA/PGA bioabsorbable membrane. Prior to placement of the membrane, the defect was filled with DBB impregnated with gentamicin sulfate 2 mg/ml. Standardized intraoral radiographs were taken prior to treatment and at the control examinations after 1 and 5 years. At baseline, the average PPD was 9.2±1.1 mm, and the average probing attachment level (PAL) was 10.1±1.6 mm; the radiographic bone level (RBL) was 10.4±2.45 mm, and an IC of 6.2±2.3 mm was present. One year after membrane placement, treatment had resulted in a PAL gain of 3.8±1.8 mm, a residual PPD of 4.2±1.3 mm, an RBL gain of 4.7±2.0 mm, and a residual IC of 2.1±1.2 mm. At the 5-year examination, two patients did not show up, and two patients had lost the treated tooth. However, both teeth were endodontically treated, and progressive periodontal destruction might not necessarily have been the reason for extraction. At the 5-year control (11 patients), the PAL gain was 4.1±1.6 mm, and the residual PPD was 4.6±1.2 mm; an RBL gain of 4.9±2.7 mm and a residual IC of 1.8±0.8 mm were observed. Statistically significant clinical improvements had occurred between baseline and the 1- and 5-year controls, whereas there were no significant differences between the 1- and 5-year results. The results of GTR with bioabsorbable membranes in combination with Bio-Oss in the treatment of periodontal intrabony defects are basically stable on a long-term basis.
TL;DR: Using the results from visual matching tests, five color frequency peaks were identified that could be used to construct an intraoral soft tissue shade guide and were found to lay in the yellow hue spectrum.
Abstract: No soft tissue shade guide is available for matching the color of denture resins to human intraoral soft tissues. To determine the color of both the gingiva and the alveolar mucosa, intraoral soft tissue colors of 150 men and women were assessed under standardized lighting conditions. Colors of the papilla, attached gingiva, and alveolar mucosa in the central incisor region of the maxilla and mandible were examined using Munsell color tabs and their corresponding notations (value, hue, chroma). Statistical evaluation was performed by using frequency tables and multiple regression (level of significance p=0.05). Color ratings for the maxillary interincisal papilla lay in the yellow hue spectrum. A high incidence of ratings was found between 7/6 2.5R and 7/4 5R (Munsell color notations). Two further peaks were identified for the colors 3/6 2.5 R and 8/4 10R. Five peaks with the highest frequency of ratings were present with regard to the color of the mucosa in the maxillary incisal region: 6/6 2.5R, 7/6 2.5R, 6/8 5R, 5/8 7.5RP, and 5/6 10RP. In the mandible, a similar pattern was found. Using the results from visual matching tests, five color frequency peaks were identified. They could be used to construct an intraoral soft tissue shade guide.
TL;DR: The null hypothesis tested in this study was that water and acidic solution storage are able to alter in vitro the resin-dentin interface, further increasing the marginal hybrid layer (MHL) permeability.
Abstract: The goal of adhesive dentistry is to restore the peripheral seal of dentin lost from removal of enamel. Unfortunately, the hybrid layer (HL) that is used to create that seal is permeable to small ions or molecules, even in the absence of detectable, interfacial gap formation via nanoleakage. This nanoleakage results from several mechanisms including incomplete infiltration of adhesive monomers into demineralized collagen matrix, presence of hydrophilic monomers, and insufficient removal of solvent or water that remains trapped inside the HL. These mechanisms lead to a porous interface with nanometer-sized channels that increase the permeability of the HL. The null hypothesis tested in this study was that water and acidic solution storage are able to alter in vitro the resin-dentin interface, further increasing the marginal hybrid layer (MHL) permeability. Class II cavities were made in vitro. The specimens were stored in water for 1 week and in lactic acid solution for 3 days. Polyvinyl siloxane impressions of restoration margins were taken before and after storage in water and lactic acid solution. Polyether replicas were obtained using the silicon impressions as molds. Replicas and original samples were observed under scanning electron microscopy. Lines of water droplets were detected on MHLs and overlying adhesive only after storage. Replicas obtained after acidic solution storage showed great numbers of irregularities such as gaps, voids, and degradation of the dentin-restoration surface margin, but also a great number of droplets. Dentin-restoration resin interfaces absorb water and are damaged by storage in dilute lactic acid. The presence of water droplets probably indicates water that flows out of the interface during the setting time of the impression and thus represents an index of marginal HL water permeability.
TL;DR: In humans, the new cementum formed after different types of regenerative therapy was of a reparative, cellular, extrinsic and intrinsic fiber type, and the regenerative modality does not seem to influence the type of newly formed cementum.
Abstract: The aim of the present study was to compare newly formed cementum following different types of regenerative therapy in humans. Eighteen patients, each displaying one advanced intrabony defect around teeth scheduled for extraction, were included in this study. The defects were treated with either guided tissue regeneration (GTR), enamel matrix protein derivative (EMD), EMD plus bioactive glass, bovine-derived xenograft (BDX), BDX plus GTR, or BDX plus EMD. After healing, the teeth were removed together with their surrounding soft and hard tissues. Cellular content, presence of artifactual splits between the new cementum and the old one or the dentin surface, and thickness of the new cementum were evaluated. Irrespective of treatment, the new cementum was of a reparative, cellular, extrinsic and intrinsic fiber type. There were no differences in cementum thickness among treatments. These findings indicate that in humans, (a) the new cementum formed after different types of regenerative therapy was, irrespective of the treatment, of a reparative, cellular, extrinsic and intrinsic fiber type, and (b) the regenerative modality does not seem to influence the type of newly formed cementum.
TL;DR: In this predominantly male population of adult patients in different age groups seeking treatment at the dental service of the German Armed Forces, periodontal bone loss gradually increased with age and prevalence of infrabony defects was very low.
Abstract: There is limited information regarding the prevalence and intraoral distribution of infrabony lesions potentially suitable for regenerative procedures in common patients seeking regular dental care in a dental practice. The aim of the present study was to investigate the prevalence and extent of alveolar bone loss and infrabony defects in randomly selected orthopantomograms of adult patients in different age groups seeking treatment at the dental service of the German Armed Forces. A total of 240 panoramic exposures were available for analysis, 60 in each of the age groups or=50 years of age. At each tooth, distances between the cementoenamel junction or margin of restoration and the alveolar crest as well as the bone level were measured with a calliper to the next 0.1 mm. Whereas virtually no bone loss was present in the youngest age group, a major change in bone level frequency distributions occurred after age 30 years. At age 50 years, about 50% of subjects had considerable bone loss of more than 4 mm at 10% or more sites, and 6 mm or more at about 5% sites. Deep infrabony defects were infrequently found before age 40 years. About 20% of patients at least 50 years of age had radiographic evidence of infrabony pockets of 4 mm or more at not more than 5% of sites. Bone loss was more pronounced in the maxilla, especially at molars. In this predominantly male population, periodontal bone loss gradually increased with age. However, prevalence of infrabony defects was very low.
TL;DR: Comparison of conclusions drawn by two different methods for comparison of blood glucose determination in capillary fingerstick blood (CFB) and gingival crevice blood (GCB) revealed that performance of the Freestyle measuring device yielded considerably large limits of agreement, andGingivalcrevice blood cannot be recommended for measuring blood glucose levels.
Abstract: The aim of the present study was to compare conclusions drawn by two different methods for comparison of blood glucose determination in capillary fingerstick blood (CFB) and gingival crevice blood (GCB). Glucose levels in CFB and GCB oozing from the gingiva after periodontal probing were measured in 31 patients with gingivitis or periodontitis using a novel, very sensitive self-monitoring device (Freestyle, TheraSense Inc.) developed for off-finger tip glucose testing. Correlation analysis revealed that measurements of glucose levels in CFB from left and right finger tips were highly correlated pointing to excellent performance of the device, whereas CFB and GCB measurements were moderately, but highly significantly, correlated. A thorough analysis of agreement revealed, on the other hand, questionable performance of the device for screening hypoglycaemic patients. The mean difference of measurements in CFB samples was +3.2±12.7 mg/dl. The 95% limits of agreement were −21.7 and +28.2. The mean difference of glucose determination in CFB and GCB samples was −22.0±26.6 mg/dl, and limits of agreement were −74.4 and +30.1. By plotting differences on means of measurements and doing linear regression analysis no systematic trend of change in differences with increasing mean of measurements was ascertained. Analysis of agreement revealed that performance of the Freestyle measuring device yielded considerably large limits of agreement, and gingival crevice blood cannot be recommended for measuring blood glucose levels.
TL;DR: This study failed to demonstrate an effect of fluoride in drinking water on caries experience when the end point was molars indicated for extraction or missing because of caries.
Abstract: The aim of this study was to assess the effect of fluoride on the severity of caries among children exposed to different concentrations of fluoride in the drinking water and living in rural areas in the Sudan. Permanently resident schoolchildren (n = 299) aged 11-13 years from three villages were clinically examined under field conditions. The caries criterion was teeth in need of extraction or extracted; only molars were recorded. Dental fluorosis was scored on all buccal tooth surfaces by the Thylstrup and Fejerskov index. The fluoride concentrations of the drinking water were assessed in samples (n = 25) collected from wells and households. Predictors of caries were assessed by logistic regression analyses. There was no significant difference regarding age and gender distribution between the areas (P > 0.05, df = 2, Kruskal-Wallis test). The socio-economic conditions in these villages were presumed to be equal. Significantly different fluoride concentrations in the drinking water were verified by the severity of dental fluorosis. Children in Abu Delaig, drinking water with 1.0-2.0 mg fluoride/L (median = 1.8), had significantly higher caries prevalence (21% versus 8%) than in a 0.4 mg fluoride area. Area was the only significant predictor for caries; odds ratio 3.7 for children in Abu Delaig compared with the low fluoride area. There was no difference in caries prevalence between the lowest and the highest fluoride (2.9 mg) area. This study failed to demonstrate an effect of fluoride in drinking water on caries experience when the end point was molars indicated for extraction or missing because of caries.
TL;DR: It is suggested that saucer-shaped restorations should be preferred for tunnel restoration in small- and mid-sized cavities.
Abstract: The aim of the present effectiveness trial was to compare the survival of restorations placed in saucer-shaped cavities to that of restorations placed in tunnel preparations. Ten operators placed a total of 85 tunnel and 97 saucer-shaped restorations. The dentinal part of the tunnel was restored by resin-modified glass ionomer cement. The remaining part of the tunnel was restored by composite resin using an adhesive technique. Composite resin was used to restore the saucer-shaped cavities. The restorations were assessed clinically and radiographically for up to 79 months, with a mean observation time of 28.8 months for tunnel, and 30.3 months for saucer-shaped restorations. The survival proportion of the tunnel restorations was 46%, and the survival proportion for the saucer-shaped restorations was 76%. A main reason for failure of the tunnel restorations was fracture of the marginal ridge (24% after 24 months). Caries development in relation to the restoration was significantly higher for tunnel restorations compared with saucer-shaped restorations (41 and 19%, respectively, after 24 months). There was no difference between the two types of restoration in marginal deterioration and caries progression in the neighboring tooth (40% after 24 months). Based on findings from the present study, it is suggested that saucer-shaped restorations should be preferred for tunnel restorations in small- and mid-sized cavities.
TL;DR: Although cultural and alimentary factors seemed to be the main risk factors in an archeological population, dental care seemed to have a strong influence on AP ratio in modern ones, which was associated with the level of dental care in the modern population.
Abstract: Apical periodontitis (AP) are frequent findings in contemporary dental practice in association with dental pathology or dental care. They have also been studied from an anthropological background. The purpose of this study was to compare the prevalence of apical and dental lesions in an archeological Middle Ages sample and a modern population, and to evaluate the influence of environmental factors. Both the archaeological sample group and dental practice subjects were from southern France. The study included full mouth surveys of 252 individuals (2,780 teeth) from a historic necropolis and 223 subjects (5,678 teeth) randomly selected from the Gard area. Tooth wear, caries, and AP were accounted for clinically and radiographically according to specific indexes. Significant differences were found between period and age in the archeological sample as regards the main risk factors for AP. Antemortem teeth loss and dental wear had been reduced, whereas caries rates and AP had increased between archaeological and modern population. The AP ratio was associated with the level of dental care in the modern population. Although significant variations could be observed between archaeological periods, the rupture in E3 (sixteenth and seventeenth centuries) leads to consider the associated population as a premodern. However, it was found that although cultural and alimentary factors seemed to be the main risk factors in an archeological population, dental care seemed to have a strong influence on AP ratio in modern ones.
TL;DR: The results indicate that the high level of persistence found in the EMF group and the highlevel of fatigability and asthenia in combination with high self-acceptance found inThe DF group represent vulnerable personalities.
Abstract: The aim of the present study was to investigate the psychobiological personality dimensions in two subgroups of patients with environmental illness (EI). Fifty-nine patients, 34 women and 25 men (a ...