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Effective management of head and neck cancer (HNC) poses a significant challenge in the field of oncology, due to its intricate pathophysiology and limited treatment options. The most common HNC malignancy is head and neck squamous cell carcinoma (HNSCC). HNSCC treatment includes a combination of surgery, radiation, and chemotherapy. While HNSCC is treatable if diagnosed early, this is often not the case and is considered incurable once in its late stages and metastatic disease has developed. Therapies are also limited once resistant disease has occurred. SP-1-39, a novel colchicine-binding site inhibitor (CBSI), has been recently reported for its potential efficacy in a variety of cancer cell lines including breast, melanoma, pancreatic, and prostate. SP-1-39 also shows abilities to overcome paclitaxel resistance in a paclitaxel-resistant prostate cancer xenograft model. To evaluate the potential of SP-1-39 as a new HNSCC treatment option, herein we systematically performed preclinical studies in HNSCC models using SP-1-39 and demonstrated that, in vitro, SP-1-39 inhibits the proliferation of 2 HNSCC cell lines with low nanomolar IC50 values (1.4 to 2.1 nM), induces HNSCC cell apoptosis in a dose-dependent manner, interferes with migration of HNSCC cells, and leads to HNSCC cell cycle arrest in the G2/M phase. In vivo, SP-1-39 suppresses the primary tumor growth of a Detroit 562 subcutaneous xenograft mouse model in 6- to 8-wk-old, male NSG (NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ) mice, with no detectable cytotoxic effects at a low dose of 2.5 mg/kg. This efficacy of SP-1-39 is better when compared with the treatment using a reference chemotherapy drug, paclitaxel at 10 mg/kg. Collectively, these data demonstrate that SP-1-39 is a promising candidate for further development for more efficacious HNSCC treatment. [ABSTRACT FROM AUTHOR]

PURPOSE: This literature review aimed to find answers to relevant questions regarding the clinical outcome of endontically treated teeth restored with fiber posts. MATERIALS AND METHODS: All clinical studies published since 1990 in journals indexed in MEDLINE were retrieved by searching PubMed with the query terms 'fiber posts and clinical studies.' The reference list of the collected articles was also screened for further relevant citations. The strength of the evidence provided by the reviewed papers was assessed according to the criteria of evidence-based dentistry. RESULTS: Five randomized controlled trials (RCTs) on fiber posts have been published in peer-reviewed journals. A meta-analysis is not applicable to these studies since they do not address the same specific clinical question. Retrospective and prospective trials without controls are also available. CONCLUSIONS: Two RCTs indicate that fiber-reinforced composite posts outperform metal posts in the restoration of endontically treated teeth. However, this evidence cannot be considered as conclusive. Longer-term RCTs would be desirable. The placement of a fiber-reinforced composite post protects against failure, especially under conditions of extensive coronal destruction. The most common type of failure with fiber-reinforced composite posts is debonding. [ABSTRACT FROM AUTHOR]

The purpose of this study was to observe microabraded enamel surfaces after various applications of Prema to evaluate the mineralized, dense outer-enamel layer. The loss of enamel during the manual method was also compared to that resulting from the mechanical method. Twenty-four intact, freshly extracted maxillary incisors were randomly divided into four groups: five applications, 10 applications, 15 applications, and 20 applications. Each group was further subdivided into manual or mechanical application. Round cavity preparations (about 3 mm) were made in the mesial or distal half on the facial surface and obturated to serve as a reference point. The compound was applied for 5 seconds, rinsed with tap water for 10 seconds, and air dried, and applications were repeated. Manual applications were performed with a Prema Hand Applicator. After the prescribed applications, the teeth were sectioned mesiodistally. Enamel losses were measured by computer image analysis. No statistically significant difference was observed between the manual and mechanical techniques. The sections were further polished down to approximately 100 µm thick and examined with polarized and transmitted light microscopy and microradiography. None of the sections showed the highly mineralized region that has been reported in previous studies. The dark superficial region reported elsewhere probably is an artifact caused by the edge effect of thicker enamel sections. [ABSTRACT FROM AUTHOR]

Wear phenomena of ceramic inlays are not fully understood. The aim of the present study was to evaluate ceramic wear, antagonist enamel wear, and luting cement wear over 8 years. The two-fold null hypothesis was that there would be (1) no difference in wear behavior between ceramic and enamel, and (2) no influence of filler content of luting composites on composite wear. From 96 restorations, 36 Class II inlays from 16 participants were selected. For inlays with opposing enamel cusps (n=17), replicas of inlays and enamel were scanned with a 3-D laser scanner. Luting gaps of inlays (n=36) were analyzed with a profilometer, including 3-D data analysis. Ceramic and enamel wear increased between 4 and 8 years, with significantly higher values for enamel after 6 years (p<0.05). Luting gap wear increased continuously up to 8 years (p<0.05), with no influence of luting composites (p>0.05) and location of teeth (p>0.05). [ABSTRACT FROM AUTHOR]

Regenerative endodontics has gained much attention in the past decade because it offers an alternative approach in treating endodontically involved teeth. Instead of filling the canal space with artificial materials, it attempts to fill the canal with vital tissues. The objective of regeneration is to regain the tissue and restore its function to the original state. In terms of pulp regeneration, a clinical protocol that intends to reestablish pulp/dentin tissues in the canal space has been developed—termed revitalization or revascularization. Histologic studies from animal and human teeth receiving revitalization have shown that pulp regeneration is difficult to achieve. In tissue engineering, there are 2 approaches to regeneration tissues: cell based and cell free. The former involves transplanting exogenous cells into the host, and the latter does not. Revitalization belongs to the latter approach. A number of crucial concepts have not been well discussed, noted, or understood in the field of regenerative endodontics in terms of pulp/dentin regeneration: (1) critical size defect of dentin and pulp, (2) cell lineage commitment to odontoblasts, (3) regeneration vs. repair, and (4) hurdles of cell-based pulp regeneration for clinical applications. This review article elaborates on these missing concepts and analyzes them at their cellular and molecular levels, which will in part explain why the non-cell-based revitalization procedure is difficult to establish pulp/dentin regeneration. Although the cell-based approach has been proven to regenerate pulp/dentin, such an approach will face barriers—with the key hurdle being the shortage of the current good manufacturing practice facilities, discussed herein. [ABSTRACT FROM PUBLISHER]

Saghiri MA, Asgar K, Lotfi M, Garcia-Godoy F. Nanomodification of mineral trioxide aggregate for enhanced physiochemical properties. International Endodontic Journal., 45, 979-988, 2012. Abstract Aim To analyse the physicochemical properties of a Nano white mineral trioxide aggregate (NWMTA) and compare it with white mineral trioxide aggregate (WMTA). Methodology White mineral trioxide aggregate and NWMTA were prepared and mixed according to the manufacturer's instructions. Surface area of powder before hydration, setting time, X-ray diffraction and microhardness at pH values of 4.4 and 7.4 were evaluated by Brunauer-Emmett-Teller, ISO Specification no.6876, Vickers microhardness, and energy-dispersive X-ray spectroscopy equipped with X-ray colour (dot) map for both cements. anova and Mann-Whitney were used for statistical analysis at a significance level of 0.5. Results The mean ± SD of surface area and setting time were 1.8 ± 0.2 m2 g−1 and 43 ± 2 min for WMTA and 7.8 ± 1.2 m2 g−1 and 6 ± 1 min for NWMTA, respectively. Mean ± SD of Microhardness were 16 ± 2, 51 ± 1, 69 ± 1 and 81 ± 2 for WMTA at pH values of 4.4 and 7.4 and for NWMTA correspondingly. Numbers of open porosity over the surface were 88 ± 24 and 44 ± 13 for WMTA and NWMTA, respectively. Statistical tests revealed significant differences between the groups ( P < 0.001) in surface area, setting time and surface hardness for both cements. Uniform distribution of strontium was only observed in NWMTA. However, other compounds were not significantly different. Conclusion Increasing surface area of powder can reduce setting time and increase microhardness even at lower pH values after hydration. [ABSTRACT FROM AUTHOR]

Saghiri MA, Asgar K, Boukani KK, Lotfi M, Aghili H, Delvarani A, Karamifar K, Saghiri AM, Mehrvarzfar P, Garcia-Godoy F. A new approach for locating the minor apical foramen using an artificial neural network. International Endodontic Journal, 45, 257-265, 2012. Abstract Aim To develop a new approach for locating the minor apical foramen (AF) using feature-extracting procedures from radiographs and then processing data using an artificial neural network (ANN) as a decision-making system. Methodology Fifty straight single-rooted teeth were selected and placed in a socket within the alveolar bone of a dried skull. Access cavities were prepared and a file was place in the canals to determine the working length. A radiograph was taken to evaluate the location of the file in relation to the minor foramen and further checked after retrieving the tooth from the alveolar socket. The location of the file tip was categorized into: beyond the AF ( long), within the root canal ( short) and just at the minor AF ( exact). Each radiograph was used to extract relevant features using K-means, Otsu method and Wavelet protocol. Thirty-six extracted features were used for training and the rest were used for evaluating the multi-layer Perceptron ANN model. Results Analysis of the images from radiographs (test samples) by ANN showed that in 93% of the samples, the location of the AF had been determined correctly by false rejection and acceptation error methods. Conclusion Artificial neural networks can act as a second opinion to locate the AF on radiographs to enhance the accuracy of working length determination by radiography. In addition, ANN can function as a decision-making system in various similar clinical situations. [ABSTRACT FROM AUTHOR]

Mendoza-Mendoza A, Solano-Reina E, Iglesias-Linares A, Garcia-Godoy F. Abalos C. Retrospective long-term evaluation of autotransplantation of premolars to the central incisor region. International Endodontic Journal, 45, 88-97, 2012. Abstract Aim This retrospective case-series study aimed to examine the long-term outcomes of autogenously transplanted premolars. Methodology Twelve patients in whom donor premolars were used to replace maxillary central incisors lost by trauma were clinically and radiologically monitored. Standardized clinical and radiographic records were systematically obtained during the follow-up period of 14 years, to determine the influence of specific clinical criteria on the overall success rate of transplantation. Results The success rate of premolar autotransplantation in the maxillary central incisor area was 80% after 14 years follow-up. The highest success rate occurred in those teeth transplanted with two-thirds of full root development. Complete pulp obliteration was positively related to autotransplant viability, followed by root formation in the bony crypt. Conclusions Autotransplantation of donor teeth, at the stage of ½ to ¾ of their expected root length, can provide a successful treatment solution for over 14 years. [ABSTRACT FROM AUTHOR]

Aim To compare bioactive and bio-adhesive therapies to enhance stem cell attachment to the root dentine of human teeth. Methodology Dentine slabs ( n = 72) were cut from the lower 3 mm of the roots of extracted human permanent teeth. The root dentine slabs were untreated, or coated with bio-adhesive, or human recombinant transforming growth factor-beta1 (hrTGF-B1), or human recombinant bone morphogenic protein-2 (hrBMP-2). The dentine slabs were placed with the root surface in contact with confluent periodontal stem cell (PSC) cultures using aseptic techniques. The cells and dentine slabs were submerged in culture media for 4, 24 and 72 h. The specimens were fixed in formalin, dehydrated and processed for scanning electron microscopy (SEM). Results SEM micrographs at ×2000 magnification revealed PSC extensive adherence to root dentine for all of the bio-adhesive and bioactive treatments. The addition of bioactive molecules did not improve PSC attachment. Few cells attached to the negative control treatments. Conclusions Bio-adhesive and bioactive growth factors were not needed to promote PSC attachment to the root dentine of human teeth, because it already appears to have good natural properties to promote PSC attachment. This suggests PSC can be used for the clinical replantation of avulsed teeth without the need for bio-adhesive and bioactive treatments. [ABSTRACT FROM AUTHOR]

Aim To measure and compare the responses of pulp tissue to cavity preparation and restoration variables using a novel tooth slice culture model. Methodology Experimental cavities (265) were continuously cut, under carefully controlled conditions, into the dentine of the labial aspect of 28-day-old Wistar rat incisors, and slices of these teeth maintained in organ culture for up to 2 weeks. The experimental variables examined were: the preparation method, remaining dentine thickness, coolant, drill speed, conditioning with EDTA and filling materials. The reactions of the dentine–pulp complex to the experimental variables were measured using pathohistometric analysis and the correlations between variables were determined using analysis of variance statistical tests. Results In rank order of surgically induced restorative pulpal injury, from the most to the least injurious were: remaining dentine thickness, absence of coolant during cavity preparation, bur speed, cavity conditioning treatments and the filling material. Conclusions To reduce pulp injury and to promote pulpal repair activity, the correct use of appropriate materials are important. However, of relatively greater importance is the operative technique adopted, the need to avoid the excess removal of dentine and to minimize trauma during preparation. [ABSTRACT FROM AUTHOR]

Wear phenomena of ceramic inlays are not fully understood. The aim of the present study was to evaluate ceramic wear, antagonist enamel wear, and luting cement wear over 8 years. The two-fold null hypothesis was that there would be (1) no difference in wear behavior between ceramic and enamel, and (2) no influence of filler content of luting composites on composite wear. From 96 restorations, 36 Class II inlays from 16 participants were selected. For inlays with opposing enamel cusps (n = 17), replicas of inlays and enamel were scanned with a 3-D laser scanner. Luting gaps of inlays (n = 36) were analyzed with a profilometer, including 3-D data analysis. Ceramic and enamel wear increased between 4 and 8 years, with significantly higher values for enamel after 6 years (p < 0.05). Luting gap wear increased continuously up to 8 years (p < 0.05), with no influence of luting composites (p > 0.05) and location of teeth (p > 0.05). [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to measure the oral health and hygiene status among 265 South Florida nursing home residents aged between 45 and 98 years. Methods: The oral health and hygiene status of the residents were assessed by noting the presence of calculus, caries, gingivitis, cheilitis, apthous ulcer, dry mouth and red or white lesions. Results: The incidence of nursing home residents with calculus was 79.6% and the remaining 20.4% were edentulous. More than half of residents had oral problems (50.6%) the commonest was gingivitis (36.6%), followed by caries (26%) and tooth fracture (15.9%). Almost half the residents wore dentures (47.2%). Statistical analysis was conducted using analysis of variance ( P-values). Ageing of the residents was statistically correlated to a worsening of oral hygiene status ( P < 0.0066), absence and presence of one or two dentures ( P < 0.0034) and a loss of teeth ( P < 0.0001). Conclusions: The ageing of residents is correlated to increasing oral health problems and the loss of teeth. Oral health neglect affects almost all of the nursing home residents. Care providers should receive education and training from dental hygienists to improve the standard of oral hygiene and health of the elderly. [ABSTRACT FROM AUTHOR]

The prevalence and levels of mutans streptococci (MS) and lactobacilli (LB) in saliva and its possible correlation with dental caries and periodontal conditions was investigated in 473 Italian schoolchildren, 9 and 13 years of age. A clinical examination and sampling of stimulated whole saliva was carried out in the school and oral health was assessed as DMFT and CPITN using the WHO criteria. The saliva samples were frozen in liquid nitrogen and after thawing, cultivated on selective media. To test the influence of cryopreservation, fresh samples from 20 subjects were cultivated. Thirty-five percent of the children were caries-free with a mean DMFT of 1.9 at the age of 13. The majority exhibited healthy periodontal conditions. Salivary MS and LB were identified in 52% and 21% of the children, respectively. The prevalence of MS was higher among the 13-year-olds than the 9-year-olds while no such difference was found regarding LB. There was a statistically positive relationship ( P<0.01) between the levels of MS and LB and both were significantly correlated to caries ( P<0.01). The correlation coefficient of microbial recovery between frozen and unfrozen samples was 0.99. In conclusion, the data provided cross-sectional information of a clear positive relationship between selected micro-organisms in saliva and caries in 9- and 13-year-old children in spite of a relatively low prevalence of the disease. The findings are discussed in a risk selection perspective. [ABSTRACT FROM AUTHOR]

Previous studies have shown that various factors such as ionic composition or pH of the extraction medium may significantly influence leaching of components from restorative materials. Therefore, it was the aim of this investigation to determine the release of fluoride from a resin-modified glass-ionomer cement (GIC) following storage in various extraction media, including an esterase buffer. Specimens of the resin-modified GIC, Fuji II LC, were stored for 144 h in deionized water, acidic buffer (pH 4.2), neutral buffer (pH 7.0), and neutral buffer supplemented with porcine liver esterase. Fluoride release into the various media was measured every 48 h over a 6-day period. In addition, activity of porcine esterase in neutral buffer (artificial saliva) was measured for up to 144 h. The data were statistically evaluated by three-way ANOVA using the Student-Newman-Keuls test ( P<0.05). It was found that esterase activity in neutral artificial saliva decreased during the first 24 h to approximately 40% of the baseline value and then remained constant for up to 6 days. Fluoride release into the various storage media varied significantly ( P<0.05). The highest amounts of fluoride were released into deionized water (30.9 ppm±1.1) and acidic buffer (26.9 ppm±0.7) after 48 h. In addition, significantly more fluoride leached into esterase-containing neutral artificial saliva (6.9 ppm±0.2) than into neutral buffer without enzyme (6.3 ppm±0.2) after 96 h. Our data indicate that fluoride release from the resin-modified GIC investigated may be increased under acidic conditions and by hydrolysis in saliva. [ABSTRACT FROM AUTHOR]

Summary. The aim of this study was to investigate (i) the effect of Gluma 2000 conditioning solution on the dentine of primary teeth, (ii) the penetration of Gluma 2000 adhesive resin into the etched dentine, (iii) the shear bond strength of a composite resin restorative material ( Pekafill) bonded with Gluma 2000 to dentine, and (iv) the depth of penetration of adhesive resin into the etched dentine as a function of the conditioning time. Dentine surfaces conditioned for 15, 30,60 and 120 seconds were examined by scanning electron microscopy. The smear layer was totally removed and, with the longer conditioning times, a fine crystalline precipitation, presumably calcium oxalate, was formed. After Gluma 2000 bonding of composite resin and dissolution of the teeth the resin interface showed excellent penetration into the etched dentine. Shear bond strengths of composite resin bonded with the adhesive resin were similar following conditioning for 15, 30, 60 and 120 seconds. Microphotographs of debonded specimens indicated that the mode of failure was cohesive within the resin. The depth of penetration of resin into etched dentine was determined by scanning electron microscopy, and a linear relationship was found between the thickness of the resin-impregnated layer and conditioning time. It was therefore concluded that depth of resin penetration and shear bond strength are not correlated. The study shows that the Gluma 2000 bonding system produces reliable adhesion of composite resin to dentine of primary teeth. Résumé. L'efficacité du Gluma 2000 pour le collage d'obturations à la résine dans les dents temporaires: étude in vitro Le but de cette étude a été de vérifier: (i) l'efficacité d'une solution de préparation de Gluma 2000 sur la dentine de dents temporaires, (ii) la pénetration de la résine de liaison dans la mordancée, (iii) la résistance de la couche de liaison d'une obturation à la résine composite (Pékafill) collée avec du Gluma 2000 à la dentine et, (iv) la profondeur de pénétration de la résine de liaison dans la dentine en fonction du temps d'application. Les surfaces dentinaires preparées avec cette solution, pendant 15, 30,60 et 120 secondes, ont été étudiée par microscope électronique à balayage. La couche de liaison a été complétement retiré et pour les temps d'application les plus longs, une précipitation de cristalline sans doute de l'oxalate de calcium s'est formée. Après collage par l'agent de liaison Gluma 2000 de la résine d'obturation et dissolution de dents, l'interface de résine montrait une excellente pénétration dans la résine mordancée. Les forces de liaison de la résine composite, collée avec l'agent de liaison, étaient similaires après préparation pendant 15, 30,60 et 120 secondes. La profondeur de pénétration de la résine dans la dentine mordancée a été étudiée au microscope électronique à balayage et une relation linéaire a été trouvée entre l'épaisseur de la couche imprégnée de résine et le temps d'application. Il a donc été conclu que la profondeur de pénétration de la résine et la résistance de la couche de liaison ne sont pas corrélées. Cette étude montre que le système de liaison Gluma 2000 donne une adhésion fiable de la résine composite à la dentine des dents temporaires. Zusammenfassung. Eine in vitro Studie zur Prüfung des Bondingeffektes von Gluma 2000 zum Milchzahndentin Das Ziel dieser Studie war wie folgend: 1. die Wirksamkeit von Gluma 2000 als 'Condioner' für Milchzahndentin zu prüfen. 2. Die Penetration von Gluma 2000 in das angeäzte Dentin. 3. die Abscherungsstärke eine Komposites (Pékafill) welches mit Gluma 2000 an Dentin gebondet wurde. 4. Die Tiefe der Penetration des Bonding-Kunststoffes in das angeäzte Dentin in Relation zur 'Conditioning-Zeitspanne' Dentinflächen wurden während 15, 30, 60 und 120 Sekunden conditioniert und darauf mit einen Elektronenmikroskop Untersucht. Die Schmierschicht wurde total entfernt. Bei längeren Konditionierzeiten hatte sich eine Kristalline Schicht, scheinbar Oxalate gebildet. Bei der Anwendung von Gluma 2000 und nach der Auflösung der Zähne zeigte sich eine exellente Penetration in das geäzte Dentin. Diese wurde elektronmikroskopisch festgestellt. Eine lineare Relation wurde gefunden zwischen der Dicke der mit Kunststoff imprägnierten Schicht und Konditioniertzeit. Daraus wurde geschlossen dass die Tiefe der Penetration des Kunststoffes und der Abscherungsstärke nicht korreliern: Die Studie zeigt dass Gluma Bondingsystem eine genügende Adhesion von Komposites zu den Milchzandentin ergibt. Resumen. Eficacia del Gluma 2000 para la unión de resina en dentina de dientes temporales: estudio in vitro Los propósitus de este fueron evaluar: (1) el efecto de la solución acondicionadora de Gluma 2000 en la dentina de dientes temporales; (2) la penetración del la resina adhesiva del Gluma 2000 en la dentina acondicionada; (3) la fuerza de cizallamiento de una resina composite (Pekafill) unida a la dentina con Gluma 2000; (4) la profundidad de penetración de la resina adhesiva en la dentina grabada como función del tiempo de acondicionamiento. Las superficies dentinarias fueron acondicionadas por 15, 30, 60, 120 segundos y examinadas con el microscopio electrónico de barrido. El barro dentinario ('smear layer') fue removido y, con los mayores tiempos de grabado, se formó una delgada precipitación cristalina, presumiblemente oxalato de calcio. Después de unir la resina con Gluma 2000 y disolución del diente, la interface de la resina mostró una excelente penetración a la dentina grabada. Las fuerzas de unión de la resina fueron similares después de 15, 30, 60 y 120 segundos. La microfotografías de los especímenes después de realizar la prueba de cizallamiento indicaron que la falla fue cohesiva en la resina. La profundidad de penetración de la resina en la dentina grabada fue determinada con el microscopio electrónico de barrido encontrándose una relación linear entre el espesor de la capa impregnada de resina y el tiempo de acondicionamiento. Se concluyó que la profundidad de penetración de la resina y la fuerza de uniôn por cizallamiento no estuvieron correlacionadas. El estudio muestra que el sistema Gluma 2000 produce una adhesión confiable de la resina composite en dientes temporales. [ABSTRACT FROM AUTHOR]

Summary. The purpose of this study was to assess the effect of etching time with Gluma 2000 conditioning agent on, first, the shear bond strength of composite resin to tooth enamel and, secondly, the micromorphology of the enamel. In the first part of the study flat enamel surfaces were prepared with 600-grit silicon carbide paper on 40 primary and 40 permanent teeth. Ten specimens of each group were etched for 15, 30, 60 or 120 seconds before applying bonding resin and restorative composite resin. After 24 hours' storage in water, the shear bond strength of each specimen was tested. Analysis of variance indicated a significant difference between the eight groups. However, the Student-Newman-Keuls test indicated that the only differences that were significant were the greater bond strengths of the 15-second primary tooth specimens compared with the 15- and 30-second permanent tooth specimens. In most cases the debonded specimens showed cohesive failure in resin close to the coupling interface. In the second part of the study the morphology of the enamel etching patterns in 96 other teeth was studied by scanning electron microscopy. The patterns were similar in primary and permanent teeth, and the longer the etching time the more pronounced was the pattern. The patterns produced in ground enamel were more uniform and predictable than those in pumiced enamel. Examination of bonded resin surfaces after dissolution of the teeth showed complete reproduction of the etched enamel surfaces, indicating excellent flow of the resin into the etched enamel. Résumé. Le propos de cette étude est d'évaluer le résultat de la durée d'application d'acide, par l'agent de conditionnement Gluma 2000, sur premièrement la force de résistance du lien à l'émail dentaire et, deuxièment, la micromorphologie de l'émail. Dans la première partie de l'étude, des surfaces d'émail planes de 40 dents temporaires et 40 dents permanentes ont été préparées avec un carbure siliconé de 600 grains. Dix spécimens de chaque groupe ont été mordancés à l'acide pendant 15, 30, 60 ou 120 secondes avant application de l'agent de liaison et obturation avec une résine composite. Après immersion dans l'eau pendant vingt-quatre heures, la résistance de la liaison de l'obturation à chaque spécimen a été testée. l'analyse de variance a montré des différences significatives entre les huit groupes. Mais, le test Student-Newman-Keuls a montré que les seules différences significatives étaient la résistance plus importante de la liaison aux 15 molaires temporaires mordancées à l'acide 15 secondes, comparée à celles des dents permanentes traitées 15 et 30 secondes. Dans la majorité des cas, les obturations descellées montraient un défaut de cohésion au niveau de l'interface. Dans la seconde partie de l'étude, la morphologie de l'émail, mordancé à l'acide, de 96 autres dents, a été étudiée au microscope électronique à balayage. Les résultats étaient similaires pour les dents temporaires et permanentes et plus marqués, quand le temps d'application était plus long. Les résultats étaient plus uniformes et prévisibles dans l'émail meulé que dans l'émail poli. l'examen des surfaces de liaison à la résine, après dissolution de la dent, montrait une reproduction des surfaces d'émail mordancé à l'acide; la résine avait donc obturé de façon compléte les microrétentions. Zusammenfassung. Ziel der vorliegenden Untersuchung war die Beurteilung der Wirksamkeit der Gluma 2000 Ätzlösung auf Schmelz von Milchzähnen (DI) und von bleibenden Zähnen (DP). Im ersten Teil der Studie wurden von 40 Milchzähnen (DI) und von 40 bleibenden Zähnen (DP) Schmelzoberflächen mit Sic-Papier der Körnung 600 präpariert. Zehn Proben jeder Gruppe wurden für 15, 30, 60 oder 120 Sekunden vor Applikation des Haftmittels und Restaurirungskunststoffes geätzt. Nach 24 stündiger lagerung in Wasser wurde vonjeder Probe die Scherbindungsfestigkeit bestimmt. Die Varianz-analyse zeigte signifkante Unterschiede zwischen acht Gruppen ( p = 0.003). Nach dem Student-Newman-Keuls Test erwiesen sich nur die Vergleiche DI15 vs DI15 und DI15 vs DP30 als signifikant unterschiedlich. Im zweiten Teil der Studie wurde die Morphologie der Schmelzätzmuster an 96 weiteren Zähnen im Rasterelektronermikroskop untersucht. Je länger die Ätzdauer, umso ausgeprägter war das Ätzmuster. Die auf präpariertem Schmelz erzeugten Äztmuster waren gleichmässiger und vorhersehbarer als die auf nur mit Bimsstein-behandeltem Schmelz. Der geätzte Schmelz wurde vom adhäsiven Resin vollständig benetzt. Nach Auflösung der Zähne kannte man die vollständigewiedergabe der geäzten Schmelzflächen sehen, was auf den ausergewöhnlichen guten Flow des Kunststoffes in den angeäzten Schmelz hinweist. Resumen. El Propósito de este trabajo fue evaluar la eficacia de la solución acondicionadora de oxalato de aluminio del agente de unión Gluma 2000 en el esmalte de dientes temporales (DI) y permanentes (DP). Para evaluar la fuerza de unión (SBS) 24 horas despues de almacenar los especímenes en agua, en 40 DI y DP se produjo una superficie plana con papel de SiC grado 600. Diez especímenes de cada grupo fueron grabados por 15, 30, 60 y 120 segundos antes de aplicar el agente de unión y la resina restauradora Pekafill. El análisis de varianza mostró que hubo diferencia significativa ( P = 0.0003) entre los 8 grupos. La prueba de Student-Newman-Keuls identificó las comparaciones DI15 vs DP15 y DI15 vs DP 30 como las únicas estadísticamente diferentes. La morfología de los patrones de grabado ácido del esmalte evaluados con el microscopio electrónico de barrido mostró que a mayor tempo de grabado, más profundo era el efecto en el esmalte. Los patrones del grabado obtenidos en esmalte tratado con el papel de SiC fueron más uniformes que los obtenidos en el esmalte tratado solo con piedra pómez. El esmalte acondicionado fue perfectamente penetrado con la resina de unión. En la mayoría de los casos, los especímenes mostraron falla cohesiva de la resina muy proxima a la interface con el esmalte. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate ceramic wear, antagonist enamel wear, and luting cement wear over 8 years. The 2-fold null hypothesis was that there would be (1) no difference in wear behavior between ceramic and enamel and (2) no influence of filler content of luting composites on composite wear. Seventeen inlays and their corresponding antagonists in 10 patients were included to test the first hypothesis. Criteria for inclusion were as follows: (1) the restorative situation of the antagonist and adjacent teeth had to be unchanged over the whole period, and (2) the contact area of the ceramic inlay had to be exclusively in enamel. Dies in Fuji Rock were made from impressions made at recall sessions at 6 months, 1 year, and 2, 4, 6, and 8 years. One-year assessments were defined as baseline, with 4-, 6-, 8-year dies serving as follow-up. Dies were scanned with a 3-dimensional laser scanner. Thirty-six inlays (with cusp inclinations below 45 degrees) from 16 patients were selected to test the second hypothesis. Twenty of these inlays were luted with a light-cured hybrid-type resin composite (filler 82 wt %), and 16 were luted with a dual-cured luting composite Variolink Low (filler 72 wt %). Three-dimensional scanning of luting gaps was done using a profilometer. Occlusal contact areas were excluded from the measurement. Data concerning the comparison of ceramic versus antagonist wear were normally distributed (Kolmogorov-Smirov test) and were therefore analyzed with paired t tests. Significant changes in wear were computed using Friedman 2-way analysis of variance (ANOVA) (P = .05). Differences between groups in the luting gap analysis were evaluated using pair-wise with the Mann-Whitney U test (P = .05). Differences over the investigation period were calculated using Friedman 2-way ANOVA. Linear regression analysis was used to assess the correlation between width and depth of the luting gap. Ceramic and enamel wear increased between 4 and 8 years, with significantly higher values for enamel after 6 years (P < .05). Luting gap wear increased continuously up to 8 years (P < .05), with no influence of luting composites (P < .05) or location of teeth (P < .05). [ABSTRACT FROM AUTHOR]