[The importance of triage in dental trauma. De differences between the hospital and dental practice]. / Het belang van triage bij tandletsel: de verschillen tussen het ziekenhuis en de tandartspraktijk.

In dental trauma, the first thought is often: 'Where is that tooth?' And, of course, it is certainly true that fast repositioning is beneficial for the prognosis of the tooth. Nevertheless, it is extremely important to focus on the condition of the patient before focussing on the treatment. A structured approach is mandatory for optimal diagnosis and treatment. This includes possible concomitant injuries such as neurotrauma. The principle of initial screening of the severity of the injury is called triage. There is a clear difference in the severity of injuries of patients with dental trauma presenting themselves in hospital or the dental practice. In hospital there are protocols for primary care; these principles can be applied in the dental practice as well.

[Dental trauma: an overview]. / Tandletsel: een overzicht.

It is estimated that, in the Netherlands, 20-30% of 18-year-olds have suffered some form of dental trauma. A third of them must bear the consequences for the rest of their lives. Adequate care and treatment can make a difference and considerably improve the prognosis of a traumatised tooth. Knowledge about the various types of injuries, forms the basis of optimal treatment. Based on the literature currently available, this article provides an overview of the ways in which details in clinical research can be helpful in more effectively estimating the risk of losing teeth and thus in determining treatment options, in such a way that they are immediately applicable in daily practice.

Adhesive luting of new CAD/CAM materials.

OBJECTIVE: To evaluate the adhesive bonding performance of recently introduced tooth-colored CAD/CAM materials after different pretreatment protocols and using different luting materials. MATERIALS AND METHODS: The CAD/CAM materials under investigation were e.max CAD (lithium disilicate glass ceramic; Ivoclar Vivadent, Schaan, Liechtenstein), Celtra Duo (zirconia-reinforced lithium disilicate ceramic; Dentsply DeTrey, Konstanz, Germany), Lava Ultimate (resin nano ceramic; 3M ESPE, Neuss, Germany), and Enamic (resin infiltrated ceramic; Vita, Bad Säckingen, Germany). A total of 240 blocks (n = 5) received various pretreatments (no pretreatment, silane, sandblasting, sandblasting + silane, hydrofluoric acid, hydrofluoric acid + silane), and then different classes of adhesive luting composites were applied (adhesive: Prime&Bond XP + SCA + Calibra; Dentsply DeTrey; self adhesive: RelyX Unicem; 3M ESPE). After 24 h water storage and 10,000 thermocycles (5°C/55°C), specimens were cut into beams and microtensile bond strengths were recorded. RESULTS: Bonding performance of recent CAD/CAM materials was clearly influenced by the pretreatment method (P < 0.05). In general, significantly higher µ-TBS values were recorded for the ceramic materials compared to the hybrid materials (P < 0.05). Among the hybrid materials, Enamic exhibited higher bond strengths than Lava Ultimate (P < 0.05). However, despite the differences found, all materials showed a high level of bonding performance, being sufficient to withstand intraoral chewing forces during mastication. CONCLUSION: When pretreated as recommended by the manufacturers, recent tooth-colored CAD/CAM materials show an encouraging bonding performance for adhesive luting.

Natural innate cytokine response to immunomodulators and adjuvants in human precision-cut lung slices.

Prediction of lung innate immune responses is critical for developing new drugs. Well-established immune modulators like lipopolysaccharides (LPS) can elicit a wide range of immunological effects. They are involved in acute lung diseases such as infections or chronic airway diseases such as COPD. LPS has a strong adjuvant activity, but its pyrogenicity has precluded therapeutic use. The bacterial lipopeptide MALP-2 and its synthetic derivative BPPcysMPEG are better tolerated. We have compared the effects of LPS and BPPcysMPEG on the innate immune response in human precision-cut lung slices. Cytokine responses were quantified by ELISA, Luminex, and Meso Scale Discovery technology. The initial response to LPS and BPPcysMPEG was marked by coordinated and significant release of the mediators IL-1ß, MIP-1ß, and IL-10 in viable PCLS. Stimulation of lung tissue with BPPcysMPEG, however, induced a differential response. While LPS upregulated IFN-γ, BPPcysMPEG did not. This traces back to their signaling pathways via TLR4 and TLR2/6. The calculated exposure doses selected for LPS covered ranges occurring in clinical studies with human beings. Correlation of obtained data with data from human BAL fluid after segmental provocation with endotoxin showed highly comparable effects, resulting in a coefficient of correlation >0.9. Furthermore, we were interested in modulating the response to LPS. Using dexamethasone as an immunosuppressive drug for anti-inflammatory therapy, we found a significant reduction of GM-CSF, IL-1ß, and IFN-γ. The PCLS-model offers the unique opportunity to test the efficacy and toxicity of biological agents intended for use by inhalation in a complex setting in humans.

Molecular identification and quantification of bacteria from endodontic infections using real-time polymerase chain reaction.

INTRODUCTION: It was the aim of the present study to evaluate root canal samples for the presence and numbers of specific species as well as for total bacterial load in teeth with chronic apical periodontitis using quantitative real-time polymerase chain reaction (PCR). METHODS: Forty adult patients with one radiographically documented periapical lesion were included. Twenty teeth presented with primary infections and 20 with secondary infections, requiring retreatment. After removal of necrotic pulp tissue or root canal filling, a first bacterial sample was obtained. Following chemo-mechanical root canal preparation a second sample was taken and a third sample was obtained after 14 days of intracanal dressing with calcium hydroxide. Analysis by real-time PCR enabled the quantification of total bacterial counts and of nine selected species. RESULTS: Root canals with primary infections harbored significantly more bacteria (by total bacterial count) than teeth with secondary infections (P < 0.05). Mean total bacterial count in the retreatment group was 2.1 x 10(6) and was significantly reduced following root canal preparation (3.6 x 10(4)) and intracanal dressing (1.4 x 10(5)). Corresponding values for primary infections were: 4.6 x 10(7), 3.6 x 10(4), and 6.9 x 10(4). The numbers of the selected bacteria and their detection frequency were also significantly reduced. CONCLUSION: Root canals with primary infections contained a higher bacterial load. Chemo-mechanical root canal preparation reduced bacterial counts by at least 95%.

Laser fluorescence measurements compared to electrical resistance of residual dentine in excavated cavities in vivo.

It has been suggested that laser fluorescence close to the dental pulp shows higher values than more distant measurements. The aim of this study was to assess fluorescence on the cavity floor and to correlate these measurements with electrical resistance as a measure of residual dentine thickness. Thirty carious lesions were excavated with a bur. The endpoint of caries removal was determined by visual, tactile and auditory means. Fluorescence was measured with the Diagnodent device and with the fluorescence feedback system of a therapeutic Er:YAG laser. Electrical resistance of the residual dentine (Prepometer units, PU) was measured with a proprietary device. Significant differences were observed between the fluorescence systems (p < 0.05). For Diagnodent, a decrease of electrical resistance of the residual dentine resulted in an increase of the fluorescence values of 2.99 units/PU (95% CI = 2.00-3.97) and an increase of 0.30 units/PU (95% CI = 0.19-0.40) for the fluorescence feedback system. For zero electrical resistance, a predicted maximum value of 51.5 units (95% CI = 41.3-61.7) was calculated for the Diagnodent and 5.1 units (95% CI = 4.1-6.2) for the feedback system. The study indicates that using the suggested detection cut-off with the Diagnodent device may be not suited to assess the endpoint of caries removal close to the dental pulp. Employing the Key Laser III, values up to 6 units might be caused solely by close proximity to the pulp, which should be considered when caries removal by laser is controlled by laser fluorescence feedback.

Teratogen metabolism: activation of thalidomide and thalidomide analogues to products that inhibit the attachment of cells to concanavalin A coated plastic surfaces.

Thalidomide metabolites inhibited the attachment of tumor cells to concanavalin A coated polyethylene surfaces. Thalidomide, itself, was non-inhibitory. Thalidomide activation to inhibitory products required hepatic microsomes, an NADPH-generating system, and molecular oxygen. Production of inhibitory metabolites was unaffected by either epoxide hydrolase or 1,2-epoxy-3,3,3-trichloropropane (TCPO), an inhibitor of epoxide hydrolase endogenous to hepatic S9 fraction. Therefore, the attachment inhibitor was probably not an arene oxide. Inhibition was not accompanied by cytotoxicity, as judged by trypan blue exclusion. Although uninduced hepatic microsomes from mice, rats and dogs had similar abilities to activate thalidomide, microsomes from Aroclor 1254 induced rats were relatively inactive in the system. Inhibitory metabolites were generated from the thalidomide analogues EM8 , EM12 , EM16 , EM87 , EM136 , EM255 , E350 , phthalimide, phthalimido-phthalimide, indan, 1- indanone and 1,3- indandione . Glutarimide , glutamic acid and phthalic acid did not activate to inhibitory products.

A high-yield sampler for toxicological characterization of complex mixtures in combustion effluents.

Combustion sampling for toxicological assessment often requires that large (greater than 100 mg) lots of complex organic mixtures of wide volatility range be rapidly recovered from high temperature gases without contamination. A new sampler, meeting these criteria for studies of public health interest, has been developed and demonstrated. The device provides high sampling rates and intimate contacting of the samples stream with large volumes of a well-cooled, liquid solvent, dichloromethane (DCM). This promotes rapid organics dissolution from carrier gas and particulates and prompt dilution and quenching of the resulting solution, resulting in high organics collection efficiencies with minimal DCM losses. Solvent separation then remits large quantities of concentrated organics for chemical analysis and toxicological testing. One- to seven-hour interrogations of in-flame, post-flame, and flue gas regions gave 50- to 250-mg yields of complex organic mixtures. In side-by-side sampling of combustion exhaust, the DCM sampler provided higher yields of DCM solubles (identified with complex organic mixtures) and of S. typhimuirim mutagens (active without exogenous metabolizing agents) than did a filter/polymeric sorbent bed sampling train. The new sampler also collects polar and high volatile hydrocarbons such as benzaheyde, pentadiyne, m- and p-diethynyl-benzene, and 1-hexen-3,5-diyne. Nitration of naphthalene and pyrene in DCM solution (1 mg/mL each) was less than 1 part in 10(7) after a 345-min exposure to a bubbling flow of moist N2/air mixture (1:1 v/v) containing 107 ppm NO and 1.5 ppm NO2, indicating that for these condition a DCM sampler should resist artifactual nitration of aromatics. However, because of the very high bacterial mutagenicity of some nitroaromatics and the wide range of sampling conditions of environmental interest, nitration and all artifacts must still be scrutinized when using the DCM sampler. The DCM sampler is expected to contribute to public health impact assessments by facilitating detailed determinations of the identities, compositions, concentrations, sources, formation mechanisms, and biological activity of environmental toxicants in gaseous atmospheres.

Er:YAG laser scaling of diseased root surfaces.

BACKGROUND: The removal of calculus and plaque is an essential component of a therapeutic approach to control periodontal disease. Er:YAG laser scaling was recently introduced as an alternative to conventional scaling procedures. In this histological study, the effects of laser instrumentation of diseased root surfaces are compared to mechanical removal of plaque and calculus with ultrasonic instruments and scalers. METHODS: Areas of subgingival calculus were identified on 40 freshly extracted human teeth. Each of these areas was randomly divided into 2 equal parts. The control site was treated either with scaling and root planing or with an ultrasonic instrument. The test site was cleaned using an Er:YAG laser according to the manufacturer's instructions. The end point of debridement was the inability to mechanically or visibly detect any remaining calculus. After pre- and postsurgical photographs and impressions for scanning electronic microscopic investigation, a plastic embedding technique was used to cut the undecalcified roots into 15 microm thick sections. RESULTS: Clinically and histologically, scaling resulted in complete debridement at all samples, producing a smooth root surface. At the test sites, laser scaling was accompanied by an increased removal of tissue and roughened surfaces. CONCLUSIONS: Laser scaling results in an increased loss of cementum and dentin, which should be taken into account in clinical situations.

Nonradiative and radiative deactivation of singlet molecular oxygen (O2(a1deltag)) in micellar media and microemulsions.

The effects of microheterogeneous media (micelles and microemulsions) on the lifetime and, to our knowledge for the first time, on the emission of singlet molecular oxygen (O2 (a1Ag), denoted as 1O2) were investigated. Micellar media and various types of microemulsions based on anionic (sodiumdodecyl sulfate), cationic (cetyltrimethylammonium chloride) or nonionic (Triton X-100) surfactants were formulated for this purpose. The nonradiative and radiative deactivation rate constants (k(d) and k(e), respectively) were determined in selected microheterogeneous media and in the pure solvents used for their formulation, by combining steady-state and time-resolved 1O2, luminescence detection techniques. We have shown that a simple additive model, as used in homogeneous mixtures of solvents, was inadequate for predicting values of k(d) and k(e) in organized media. In contrast, both 1O2 lifetimes (taudelta = 1/k(d)) and k(e) in the microheterogeneous systems investigated could be predicted with good precision from the composition of the media and the taudelta and k(e) values in the pure solvents, using a two-pseudophase kinetic model for the 1O2 distribution. Such a model takes into account the average times spent by 1O2 in the aqueous and lipophilic pseudo-phases of the organized media, the corresponding equilibrium constant (Keq) depending on the nature of the system.

Clinical and microbiological effects of local chlorhexidine applications.

AIM: To study the effects of an application of chlorhexidine varnish (40%) on dental plaque. DESIGN: Randomised controlled clinical trial. SUBJECTS: 40 patients (50% females), aged 25-34 years after undergoing any necessary restorative treatment. Exactly one half of these individuals practiced good oral hygiene, the efforts of the others were poor. METHOD: Test groups received a chlorhexidine varnish application, the control group received a placebo varnish. Initially and after 2 and 6 weeks, a modified Dentocult SM-test, bleeding on probing, and a plaque index (Quigley-Hein) were recorded. RESULTS: In contrast to the control group, improvements in plaque index and bleeding on probing scores were found in patients with poor oral hygiene. The results of the Dentocult SM-tests showed a considerable reduction of streptococcus colonisation. The test group with good oral hygiene showed only slight improvement of the examined indices after chlorhexidine application. The index parameters of all patients of the placebo groups remained unchanged over the examination time period. CONCLUSION: The application of a chlorhexidine varnish reduced the quantity of the Streptococcus mutans colonies significantly and improved clinical parameters in patients with elevated plaque accumulation.

Degradation of polyvinyl alcohol (PVA) by homogeneous and heterogeneous photocatalysis applied to the photochemically enhanced Fenton reaction.

The reaction mechanism of the oxidative degradation of polyvinyl alcohol (PVA) by the photochemically enhanced Fenton reaction was studied using a homogeneous (Fe2+(aq) + H2O2) and a heterogeneous reaction system (iron(III)-exchanged zeolite Y+ H2O2). In the homogeneous Fenton system, efficient degradation was observed in a batch reactor, equipped with a medium pressure mercury arc in a Pyrex envelope and employing 80% of the stoichiometric amount of H2O2 required for the total oxidation of PVA and a concentration ratio as low as I mole of iron(II) sulfate per 20 moles of PVA sub-units (C2H40). Model PVA polymers of three different molecular weights (15,000, 49,000 and 100,000 g mol(-1)) were found to follow identical degradation patterns. Strong experimental evidence supports the formation of supermacromolecules (MW: 1-5 x 10(6) g/mol) consisting of oxidized PVA and trapped iron(III) at an early reaction stage. Low molecular weight intermediates, such as oxalic acid, formic acid or formaldehyde were not found during PVA degradation in the homogeneous Fenton system, and we may deduce that the manifold of degradation reactions is mainly taking place within the super-macromolecules from which CO2 is directly released. However, in the heterogeneous Fenton system, the reaction behavior was found to be distinctly different: a decrease of the molecular weights of all three tested monodisperse PVA samples was observed by the broadening of the GPC-traces during irradiation, and oxalic acid was formed. The results lead to the mechanistic hypothesis that during the heterogeneous Fenton process, the cleavage of the PVA-chains may occur at random positions, the reactive centres being located inside the iron(III)-doped zeolite Y photocatalysts.

[Effect of nonelectrolytes on the polymerization of G-actin]. / Vliianie neélektolitov na polimerizatsiiu G-aktina.

The non-electrolytes--urea, thiourea, sucrose, glycerin, polyethylendioxid, glutaraldehyde--inhibit polymerization of G-actin in vitro. The results are discussed in association with the capability of some non-electrolytes preventing colloid reactions of alterated protoplasm and increasing the stability of cells to injuring agents.

[Synthesis and breakdown of pyridine nucleotide coenzymes in the cell nuclei of guinea pig kidneys in diphtheria intoxication]. / Sintez i raspad piridinnukleotidnykh kofermentov v iadrakh kletok pochek morskoi svinki pri difteriinoi intoksikatsii.

The effect of diphteria toxin on the synthesis and degradation of NAD+ and the hydrolysis of NADP+ in the nuclei of guinea pig kidney were studied. Treatment of animals with diphteria toxin (DT) results in considerable reduction of NADpyrophosphorylase activity, which starts 12 hours after incubation and is minimal (50% of that of the control animals) 18 hours after it. During this time interval DT does not affect the activity of NADase and decreases that of NADPase in the nuclei. Thus under diphterial intoxication a decrease of NADPase activity, the synthesis of NAD+ being reduced, probably provides for kidney cells more favourable conditions for maintenance of their synthetic reactions and for restoration of their normal metabolism. It was found that the non-ionic detergent Triton X-100 promotes the NADpyrophosphorylase activity in cell nuclei of intact animals by 40% (on the average) and does not affect the NAD+ synthesis in DT injected animals. Therefore DT not only reduces the nuclear NADpyrophosphorylase activity but also affects the nuclear envelope. The alteration of nuclei under DT treatment is suggested by the decrease of their histone content (30% on the average as compared with the control). The decrease of NADpyrophosphorylase activity under DT intoxication can be considered as an adaptive reaction limiting the availability of NAD+ as the substrate of the EF2 mono (ADP-ribosilation) which results in its unability to promote translation.

[The effect of different antitubercular agents on phagosome fusion with lysosomes, on the F-actin content in mouse peritoneal macrophages and on G-actin polymerization in vitro]. / Vliianie razlichnykh protivotuberkuleznykh sredstv na sliianie fagosom s lizosomami, na soderzhanie F-aktina v peritoneal'nykh makrofagakh myshi i na polimerizatsiiu G-aktina in vitro]

Effects of various antituberculosis remedies (ATR)--isoniazid (INA), saluzid (SA), streptosaluzid (SS), ethambutol (EB), sodium para-aminosalicylate (SPAS) on phagosome-lysosome (PL) fusion, on F-actin content in mouse macrophages and on G-actin polymerization in vitro were studied. The ATR of choice have been shown to stimulate the PL fusion. INA (0.2 mM), SA (0.02 mM), SS (0.05 mM), EB (0.08 mM) and SPAS (0.5 mM) increased the F-actin content and changed its localization within macrophages. ATR changed the character of G-actin polymerization in vitro. Possible mechanisms of interrelation between cytoskeleton (actin part) changes and PL fusion are discussed. The results obtained suggest to use the ATR-induced changes in PL fusion and F-actin content in the cells for estimating therapeutic effects of respective antituberculosis remedies.

Local treatment with BPPcysMPEG reduces allergic airway inflammation in sensitized mice.

According to the hygiene hypothesis, triggering the immune system with microbial components during childhood balances the inherent Th2 bias. In contrast, specific immunotherapy involves exposure of the patient to the allergen in order to achieve desensitization to subsequent contact. In a human in vitro allergy model the potential of the TLR2/6 agonist BPPcysMPEG to modulate antigen presenting cells and allergen-specific immune responses was evaluated. Specific immunomodulation via co-administration of the allergen and BPPcysMPEG enhanced expression of co-stimulatory molecules on DC and increased secretion of the proinflammatory cytokine TNF-α. Acting as an adjuvant, BPPcysMPEG elevated allergen-specific immune responses in co-culture with autologous lymphocytes. Although administration of BPPcysMPEG alone enhanced expression of co-stimulatory molecules on DC, proliferation of autologous lymphocytes was not induced. Based on this finding, the potential of BPPcysMPEG to reduce allergic airway inflammation by preventive modulation of the innate immune system via TLR2/6 agonization was investigated in mice. Local administration of BPPcysMPEG altered cellular influx and cell composition in BAL fluid. Furthermore, the Th2-associated cytokines IL-4 and IL-5 were diminished. Allergen-specific restimulation of cells from mediastinal lymph nodes and splenocytes suggested an alteration of immune responses. The treatment with BPPcysMPEG induced a Th1-dominated cytokine milieu in mediastinal lymph nodes, while allergen-specific immune responses in splenocytes were diminished. The co-administration of allergen and BPPcysMPEG reduced cytokine secretion upon restimulation in mediastinal lymph nodes and splenocytes. From these data we conclude that BPPcysMPEG was able to influence the immune system with regard to subsequent allergen contact by TLR2/6 agonization.

[Two-year results of a modular short hip stem prosthesis--a prospective study]. / Zwei-Jahres-Ergebnisse einer modularen Kurzschaft-Hüftendoprothese--eine prospektive Studie.

AIM: The short-term results of a prospective, consecutive series of 50 cementless modular short hip stem endoprostheses are reported. METHOD: 48 cases were available for clinical and radiological follow-up at an average time of 2.4 years post-op. One patient did not consent to a follow-up investigation, 1 early revision was necessary 4 weeks post-op after a fall precipitating a periprosthetic fracture. RESULTS: The average age at the time of THA was 54 years and the Harris hip score reached 95 points at the time of follow-up. One implant had aseptic loosening and 1 implant was revised due to a failure of the modular titanium neck adapter. An equal number of patients received modular neck adapters with neutral or 7.5 degrees retroversion. No 140 degrees neck and no anteverted neck adapters were used. Radiological results of the 2/3 porous coated hip stem showed a metaphyseal bone remodelling with hypertrophies in coated Gruen zones 3 (17%) and 6 (46%) and marked spot welds and increased bone density (86%) in the distal area of the coating. Primary implant migration between 2 and 10 mm was present in 7 cases due to a low osteotomy and implant position combined with an implant undersizing and lack of proximal-lateral support. At the time of the last follow-up these cases had no clinical symptoms with an average HHS of 96 points and with full bony integration. CONCLUSION: Our results support the use of the investigated short hip stem for THA when the femoral bone quality and morphology support the metaphyseal anchoring concept. The surgical technique must avoid a stem position without proximal-lateral cortical contact to the femoral osteotomy, as this reduces primary implant stability. Further follow-up is necessary to validate the long-term success of this procedure.

Bicontact Plasmacup THA in patients with staged bilateral hip replacement.

AIM: In a retrospective study, all patients with bilateral cementless Bicontact-Plasmacup total hip arthroplasty in the period May 1993 to June 2000 were followed up clinically and radiologically. METHOD: Out of 537 hip replacements performed in this period with this combination of implants, 46 patients had bilateral surgery. At follow-up, the Harris Hip Score, the radiological changes between primary implantation and most recent follow-up and the radiologically visible wear of the polyethylene cup component were studied. RESULTS: Thirty-seven patients were followed up. One patient had died and 8 patients could not be contacted. The average age at the first hip replacement was 57.8 years and it was 59.1 years at the second operation. The follow-up period was 6.5 years (min 4.8 and max 9.8 years). The average Harris Hip Score at the time of follow-up was 91 points. Up to the time of follow-up, no stem or cup implant had to be revised. There were no radiological signs of stem loosening. In the case of the cup components, increased linear wear values of more than 0.15 mm/year were found in 4 THAs that used a 28-mm ceramic-polyethylene bearing. In two of these cases, the cup was in a markedly steep position. One of these cup components was assessed as loosened. CONCLUSION: The results of this study have confirmed the biomechanical concept of the implant system employed. In contrast to the stem design, the cup design and slide bearing options have been supplemented in the meantime. The ceramic bearing was only available from 1997 and was used less often in this group of patients than would be indicated today for patients of the same age and degree of activity.

Penetration depth of a dye marker into dentine using a novel hydrodynamic system (RinsEndo).

AIM: To investigate the efficiency of a hydrodynamic irrigation system compared with conventional cleansing techniques in root canals. METHODOLOGY: Forty-five freshly extracted single-rooted teeth were de-coronated and their root canals were enlarged to size 30 at the apex. The teeth were randomly divided into three groups (n = 15) for the final rinsing sequence using 2% NaOCl plus acid fuchsin: group I: static application of irrigant, 3 min; group II: flushing with a syringe; 5-mL NaOCl, 1 min; group III: RinsEndo-system; 5-mL NaOCl, 50 s. Apical extrusion was documented photographically. The roots were sectioned at 2, 4, 6 and 8 mm from their apices and the penetration depths of dye into dentine measured, using a stereomicroscope. Wilcoxon's test and Pearson's chi-squared test were employed to prove statistic relevance. RESULTS: Greater dye penetration depth into the dentinal tubules was achieved when employing hydrodynamic rinsing procedures. Using this technique, 23% of the specimens were penetrated for more than 50% of their dentine thickness, whereas the results for flushing with a syringe were 12% (static application, 7%). No penetration of dentine occurred in 63% of specimens with static application, 39% flushing with a syringe and 15% using the hydrodynamic system (P < 0.05 Pearson's chi-squared test). Apical extrusion occurred more frequently after hydrodynamic rinsing (extruded specimens: RinsEndo = 80%; static application/flushing with a syringe = 13%; P < 0.05 Pearson's chi-squared test). CONCLUSIONS: Hydrodynamic rinsing demonstrated an improvement over conventional methods in terms of dentine penetration of a dye marker. A higher risk of apical extrusion with the RinsEndo-system was evident.

The influence of the calibration mode of a laser fluorescence device on caries detection.

The aim of the present study was to assess the influence of the calibration mode of a laser fluorescence measurement device on caries detection. While positioning the probe on an occlusal carious lesion or stained fissure using a clamp, the occlusal surface of each of 62 teeth was covered with a light-body silicone impression material to facilitate a reproducible probe position. Then, measurements of the occlusal lesions were performed after standard and individual calibration at four non-carious areas on the buccal surface of each tooth. Mean laser fluorescence values of the occlusal reading point following standard calibration were about 4-5 units higher compared to values measured after individual calibration. After 1 week, readings after both standard and individual calibration were not different from baseline values (p > 0.05). During individual calibration, a mean range of about 2 units could be observed when comparing the readings of the occlusal reading point with respect to the four different areas of each buccal surface. The present study indicates that laser fluorescence readings are dependent on the mode of calibration. Moreover, for individual calibration, the probe position has to be recorded carefully. It is suggested that the same mode of calibration should always be used, when employing laser fluorescence measurements for longitudinal caries monitoring.