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Objective: To assess the implication of COVID-19 pandemic on the practice of restorative dentistry in Nigeria.Materials and Methods: A cross-sectional study regarding the impact of COVID-19 on restorative dental practice was carried out among dentists across different cadres working in either private or public practice. Data was obtained using an online survey questionnaire regarding the infection control practice, availability and use of personal protective equipment, practice modifications to combat COVID-19 outbreak and the impact of COVID-19. Data was analysed using the chi-square test and p-value <0.05 was considered statistically significant.Results: Amongst 137 dentists that participated in the study, majority of respondents were males (58.4%), a greater proportion (49.6%) were in the age range 35-44 years and 78.1% worked in public hospitals. A significantly higher number of male respondents (p=0.019) and public dental workers (p=0.036) immediately changed their mode of dental service delivery following the COVID-19 outbreak. Majority of respondents (60.6%) carried out restorative dental procedures despite the pandemic; most of these procedures being emergency dental treatment and non-aerosol generating dental procedures. About half of respondents had respiratory masks (51.8%) and isolation gowns (54.0%) available. Majority reported that the pandemic had decreased patient flow (88.3%), increased treatment fee (53.3%) and had an impact on the income generated (92%). Only 20.4% of respondents hadproblems with their staff; the problems being emotional problems, work abandonment and demand of salary increase. The pandemic has had a negative impact on most respondents (74.5%) and only 31.4% respondents were optimally prepared to render dental services.Conclusion: COVID-19 pandemic has changed the mode of restorative dental practice in Nigeria; resulting in a psychological impact on dentists and a financial burden on dental practice. &nbsp

Decayed or damaged tooth structure is widely being repaired with the resin based dental composites (RBCs) in the clinical practice. However, relatively high failure rate and short lifespan are common in the case of the larger posterior teeth restorations, caused by the polymerization shrinkage of RBCs. In order to reduce the polymerization shrinkage inorganic dental inserts were introduced. The aim of this study was to fabricate dental inserts based on hydroxyapatite doped with 5 mol. % of magnesium ions (MgHAP) and determine their bonding ability with a restorative material widely used in the clinical practice – Clearfil Universal adhesive. The MgHAP powder and insert were characterized using energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) analysis and scanning electron microscopy (FE-SEM). Bonding ability of the inserts with restorative material was measured by shear bond strength (SBS) test, and the type of fracture was determined by the optical microscope. The obtained mean SBS value of the MgHAP inserts was 12.7 MPa, with mostly cohesive type of the fracture present. These inserts present promising dentin substitutes for application in the restorative dentistry.

Decayed or damaged tooth structure is widely being repaired with the resin based dental composites (RBCs) in the clinical practice. However, relatively high failure rate and short lifespan are common in the case of the larger posterior teeth restorations, caused by the polymerization shrinkage of RBCs. In order to reduce the polymerization shrinkage inorganic dental inserts were introduced. The aim of this study was to fabricate dental inserts based on hydroxyapatite doped with 5 mol. % of magnesium ions (MgHAP) and determine their bonding ability with a restorative material widely used in the clinical practice – Clearfil Universal adhesive. The MgHAP powder and insert were characterized using energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) analysis and scanning electron microscopy (FE-SEM). Bonding ability of the inserts with restorative material was measured by shear bond strength (SBS) test, and the type of fracture was determined by the optical microscope. The obtained mean SBS value of the MgHAP inserts was 12.7 MPa, with mostly cohesive type of the fracture present. These inserts present promising dentin substitutes for application in the restorative dentistry.

Objective: To assess the implication of COVID-19 pandemic on the practice of restorative dentistry in Nigeria.Materials and Methods: A cross-sectional study regarding the impact of COVID-19 on restorative dental practice was carried out among dentists across different cadres working in either private or public practice. Data was obtained using an online survey questionnaire regarding the infection control practice, availability and use of personal protective equipment, practice modifications to combat COVID-19 outbreak and the impact of COVID-19. Data was analysed using the chi-square test and p-value <0.05 was considered statistically significant.Results: Amongst 137 dentists that participated in the study, majority of respondents were males (58.4%), a greater proportion (49.6%) were in the age range 35-44 years and 78.1% worked in public hospitals. A significantly higher number of male respondents (p=0.019) and public dental workers (p=0.036) immediately changed their mode of dental service delivery following the COVID-19 outbreak. Majority of respondents (60.6%) carried out restorative dental procedures despite the pandemic; most of these procedures being emergency dental treatment and non-aerosol generating dental procedures. About half of respondents had respiratory masks (51.8%) and isolation gowns (54.0%) available. Majority reported that the pandemic had decreased patient flow (88.3%), increased treatment fee (53.3%) and had an impact on the income generated (92%). Only 20.4% of respondents hadproblems with their staff; the problems being emotional problems, work abandonment and demand of salary increase. The pandemic has had a negative impact on most respondents (74.5%) and only 31.4% respondents were optimally prepared to render dental services.Conclusion: COVID-19 pandemic has changed the mode of restorative dental practice in Nigeria; resulting in a psychological impact on dentists and a financial burden on dental practice. &nbsp

Objective: To assess the implication of COVID-19 pandemic on the practice of restorative dentistry in Nigeria.Materials and Methods: A cross-sectional study regarding the impact of COVID-19 on restorative dental practice was carried out among dentists across different cadres working in either private or public practice. Data was obtained using an online survey questionnaire regarding the infection control practice, availability and use of personal protective equipment, practice modifications to combat COVID-19 outbreak and the impact of COVID-19. Data was analysed using the chi-square test and p-value <0.05 was considered statistically significant.Results: Amongst 137 dentists that participated in the study, majority of respondents were males (58.4%), a greater proportion (49.6%) were in the age range 35-44 years and 78.1% worked in public hospitals. A significantly higher number of male respondents (p=0.019) and public dental workers (p=0.036) immediately changed their mode of dental service delivery following the COVID-19 outbreak. Majority of respondents (60.6%) carried out restorative dental procedures despite the pandemic; most of these procedures being emergency dental treatment and non-aerosol generating dental procedures. About half of respondents had respiratory masks (51.8%) and isolation gowns (54.0%) available. Majority reported that the pandemic had decreased patient flow (88.3%), increased treatment fee (53.3%) and had an impact on the income generated (92%). Only 20.4% of respondents hadproblems with their staff; the problems being emotional problems, work abandonment and demand of salary increase. The pandemic has had a negative impact on most respondents (74.5%) and only 31.4% respondents were optimally prepared to render dental services.Conclusion: COVID-19 pandemic has changed the mode of restorative dental practice in Nigeria; resulting in a psychological impact on dentists and a financial burden on dental practice. &nbsp

Direct pulp capping materials ideally promote the formation of dentin bridge. Mineral trioxide aggregate is mostly used for direct pulp capping. However, this material showed difficult sealing ability and poor handling. Phosphorylated pullulan has recently gained attention because of its high biocompatibility, bioadhesive behavior and dentin regeneration ability. It shows high biocompatibility and is capable to act as a carrier and can adhere to hard tissue. The purpose of this study was to histologically evaluate monkeys’ pulpal responses to a newly developed material phosphorylated pullulan containing mineral trioxide aggregates as a direct pulp capping and to evaluate its sealing ability using scanning electron microscopy (SEM). Cavities were prepared in monkey’s teeth. The pulps were intentionally exposed and randomly divided into four groups according to the application of pulp capping materials – a newly developed direct pulp capping material containing phosphorylated pullulan (PL), conventional direct pulp capping materials such as NEX-MTA cement (NX), Theracal LC (TH) and Dycal (DY). The teeth were then extracted after 3, 7 and 70 days, fixed and prepared according to routine histological techniques to observe pulpal reactions. Tissues were demineralized and subsequently sectioned. Sections were stained with hematoxylin / eosin for micromorphological observation. SEM observation was performed to study the pulp capping material / dentin interface. No serious inflammatory reactions of the pulp, such as necrosis or abscess formation were observed in PL group. For PL, dentin bridge was very thick and dentinal tubule and odontoblast cells were observed at 70 days. SEM observation revealed good sealing ability of PL.

Direct pulp capping materials ideally promote the formation of dentin bridge. Mineral trioxide aggregate is mostly used for direct pulp capping. However, this material showed difficult sealing ability and poor handling. Phosphorylated pullulan has recently gained attention because of its high biocompatibility, bioadhesive behavior and dentin regeneration ability. It shows high biocompatibility and is capable to act as a carrier and can adhere to hard tissue. The purpose of this study was to histologically evaluate monkeys’ pulpal responses to a newly developed material phosphorylated pullulan containing mineral trioxide aggregates as a direct pulp capping and to evaluate its sealing ability using scanning electron microscopy (SEM). Cavities were prepared in monkey’s teeth. The pulps were intentionally exposed and randomly divided into four groups according to the application of pulp capping materials – a newly developed direct pulp capping material containing phosphorylated pullulan (PL), conventional direct pulp capping materials such as NEX-MTA cement (NX), Theracal LC (TH) and Dycal (DY). The teeth were then extracted after 3, 7 and 70 days, fixed and prepared according to routine histological techniques to observe pulpal reactions. Tissues were demineralized and subsequently sectioned. Sections were stained with hematoxylin / eosin for micromorphological observation. SEM observation was performed to study the pulp capping material / dentin interface. No serious inflammatory reactions of the pulp, such as necrosis or abscess formation were observed in PL group. For PL, dentin bridge was very thick and dentinal tubule and odontoblast cells were observed at 70 days. SEM observation revealed good sealing ability of PL.

Yamaguchi S., Lee C., Karaer O., et al. Predicting the Debonding of CAD/CAM Composite Resin Crowns with AI. Journal of Dental Research, 98(11), 1234-1238. © 2019 Sage Publications. DOI: 10.1177/0022034519867641., A preventive measure for debonding has not been established and is highly desirable to improve the survival rate of computer-aided design/computer-aided manufacturing (CAD/CAM) composite resin (CR) crowns. The aim of this study was to assess the usefulness of deep learning with a convolution neural network (CNN) method to predict the debonding probability of CAD/CAM CR crowns from 2-dimensional images captured from 3-dimensional (3D) stereolithography models of a die scanned by a 3D oral scanner. All cases of CAD/CAM CR crowns were manufactured from April 2014 to November 2015 at the Division of Prosthodontics, Osaka University Dental Hospital (Ethical Review Board at Osaka University, approval H27-E11). The data set consisted of a total of 24 cases: 12 trouble-free and 12 debonding as known labels. A total of 8,640 images were randomly divided into 6,480 training and validation images and 2,160 test images. Deep learning with a CNN method was conducted to develop a learning model to predict the debonding probability. The prediction accuracy, precision, recall, F-measure, receiver operating characteristic, and area under the curve of the learning model were assessed for the test images. Also, the mean calculation time was measured during the prediction for the test images. The prediction accuracy, precision, recall, and F-measure values of deep learning with a CNN method for the prediction of the debonding probability were 98.5%, 97.0%, 100%, and 0.985, respectively. The mean calculation time was 2 ms/step for 2,160 test images. The area under the curve was 0.998. Artificial intelligence (AI) technology—that is, the deep learning with a CNN method established in this study—demonstrated considerably good performance in terms of predicting the debonding probability of a CAD/CAM CR crown with 3D stereolithography models of a die scanned from patients.

Purpose: Connective tissue grafts are widely documented as a predictable technique for treating Miller Class I and II recessions, as well as procedures in which soft tissue augmentation is required for aesthetic reasons. This article aims to explore the resolution of a clinical case with this type of problem. Clinical case: This case describes a technique for reconstructing a pontic area and adjacent papilla by means of two consecutive connective tissue grafts. The first graft served to increase the amount of tissue in the horizontal direction, and the second promoted vertical reconstruction of the defect. Results and Conclusion: In cases with aesthetic requirements, restorative intervention may be able to mask tissue loss, but it can hardly achieve optimal aesthetic results. Periodontal plastic surgery techniques can be used to achieve that ideal result. The clinician must diagnose conditions in order to select correct treatment regimen for each individual case.

Biomimetics is the science of imitating nature is a growing multidisciplinary field, which is now leading to the fabrication of novel materials with remarkable mechanical properties. It is the study of biological structures, their functions and synthetic pathways emerging at the intersection between cellular biology, molecular biology, material sciences, dentistry and medicine. Bio meaning life and Memesis meaning imitation are derived from Greek words. Perceptions regarding the scope of biomimetics appear to vary widely depending upon the specialized discipline of the investigation. Biomimetics provides a new strategy that translates our knowledge of biological structures and functions and creates new synthetic pathways to mimic biological processes.

Introduction. Due to the educational process inertia based on textbook literature, teaching of undergraduate students in dental schools is often behind modern practice. From the aspect of minimally invasive dentistry, composites are materials of choice for the reconstruction of most lesions in posterior teeth. The objective of the study was to systematize data about theoretical and practical teaching of undergraduate students regarding the application of posterior resin composites in the world's dental schools and compare it with the data obtained from the School of Dental Medicine, University of Belgrade. Material and Methods. MEDLINE database was searched for articles based on keywords dental education and posterior composites. Only articles published in the last five years and those which used the same questionnaire were included in the study. Results. Data were analyzed for the dental schools from the UK and Ireland, Spain, Japan, United States and Canada. Increased theoretical and practical teaching of students regarding posterior composites is noted in most schools. The dominant contraindication for using resin composite is allergy to its ingredients. Rubber dam is the most common method of providing aseptic conditions and dry field in the world, whereas in our school it is used in negligible number of cases. In a number of schools, metal matrices and wooden wedges are recommended for the proximal cavity restoration. Glass-ionomer cement is commonly used as a liner. Polishing and finishing of restorations is performed in the same session in 90-100% of the schools except in Japan, where it is carried out after 24 hours. Conclusion. Theoretical and practical teaching of posterior composite restorations is increasing in the world's dental centers. It is necessary to harmonize teaching in our school with international trends in the use of rubber dam, certain aspects of cavity design and protocols for the treatment of deep caries lesions., Uvod. Stomatološka edukacija na osnovnim studijama često zaostaje za savremenom praksom zbog tromosti našeg nastavnog procesa, koji je zasnovan na udžbeničkoj literaturi. S aspekta minimalno invazivne stomatologije, kompoziti su materijali izbora za rekonstrukciju većine lezija na bočnim zubima. Cilj rada je bio da se sistematizuju podaci iz svetskih centara o teorijskoj i praktičnoj edukaciji studenata osnovnih studija stomatologije o primeni kompozita u bočnoj regiji i uporede s edukacijom na Stomatološkom fakultetu Univerziteta u Beogradu. Materijal i metode rada. Pretraživanjem baze podataka MEDLINE prema ključnim rečima dental education i posterior composites, odabrana su istraživanja objavljena u poslednjih pet godina u kojima su korišćene istovetne ankete. Rezultati. Analizirani su podaci za stomatološke škole u Velikoj Britaniji i Irskoj, Španiji, Japanu, Sjedinjenim Američkim Državama i Kanadi. U većini škola uočava se trend povećanja teorijske i praktične obuke učenika. Jedina dominantna kontraindikacija je alergija na sastojke kompozitnih materijala. Koferdam je najčešća metoda obezbeđivanja aseptičnih uslova i suvog polja rada u svetu, dok se kod nas koristi u zanemarljivom broju slučajeva. Najveći broj škola zastupa metalne matrice i drvene kočiće za proksimalne kavitete. Glasjonomer- cement se najčešće koristi za podlaganje dubokih kaviteta. Završna obrada ispuna u istoj seansi se primenjuje u 90-100% škola, osim u Japanu, gde se vrši i odložena obrada nakon 24 časa. Zaključak. Teorijska i praktična nastava o kompozitima u bočnoj regiji sve je češća u svetskim centrima. Potrebno je usklađivanje nastave kod nas s međunarodnim trendovima u pogledu primene koferdama, pojedinih aspekata dizajna kaviteta i protokola za lečenje dubokog karijesa.

Introduction. Due to the educational process inertia based on textbook literature, teaching of undergraduate students in dental schools is often behind modern practice. From the aspect of minimally invasive dentistry, composites are materials of choice for the reconstruction of most lesions in posterior teeth. The objective of the study was to systematize data about theoretical and practical teaching of undergraduate students regarding the application of posterior resin composites in the world's dental schools and compare it with the data obtained from the School of Dental Medicine, University of Belgrade. Material and Methods. MEDLINE database was searched for articles based on keywords dental education and posterior composites. Only articles published in the last five years and those which used the same questionnaire were included in the study. Results. Data were analyzed for the dental schools from the UK and Ireland, Spain, Japan, United States and Canada. Increased theoretical and practical teaching of students regarding posterior composites is noted in most schools. The dominant contraindication for using resin composite is allergy to its ingredients. Rubber dam is the most common method of providing aseptic conditions and dry field in the world, whereas in our school it is used in negligible number of cases. In a number of schools, metal matrices and wooden wedges are recommended for the proximal cavity restoration. Glass-ionomer cement is commonly used as a liner. Polishing and finishing of restorations is performed in the same session in 90-100% of the schools except in Japan, where it is carried out after 24 hours. Conclusion. Theoretical and practical teaching of posterior composite restorations is increasing in the world's dental centers. It is necessary to harmonize teaching in our school with international trends in the use of rubber dam, certain aspects of cavity design and protocols for the treatment of deep caries lesions., Uvod. Stomatološka edukacija na osnovnim studijama često zaostaje za savremenom praksom zbog tromosti našeg nastavnog procesa, koji je zasnovan na udžbeničkoj literaturi. S aspekta minimalno invazivne stomatologije, kompoziti su materijali izbora za rekonstrukciju većine lezija na bočnim zubima. Cilj rada je bio da se sistematizuju podaci iz svetskih centara o teorijskoj i praktičnoj edukaciji studenata osnovnih studija stomatologije o primeni kompozita u bočnoj regiji i uporede s edukacijom na Stomatološkom fakultetu Univerziteta u Beogradu. Materijal i metode rada. Pretraživanjem baze podataka MEDLINE prema ključnim rečima dental education i posterior composites, odabrana su istraživanja objavljena u poslednjih pet godina u kojima su korišćene istovetne ankete. Rezultati. Analizirani su podaci za stomatološke škole u Velikoj Britaniji i Irskoj, Španiji, Japanu, Sjedinjenim Američkim Državama i Kanadi. U većini škola uočava se trend povećanja teorijske i praktične obuke učenika. Jedina dominantna kontraindikacija je alergija na sastojke kompozitnih materijala. Koferdam je najčešća metoda obezbeđivanja aseptičnih uslova i suvog polja rada u svetu, dok se kod nas koristi u zanemarljivom broju slučajeva. Najveći broj škola zastupa metalne matrice i drvene kočiće za proksimalne kavitete. Glasjonomer- cement se najčešće koristi za podlaganje dubokih kaviteta. Završna obrada ispuna u istoj seansi se primenjuje u 90-100% škola, osim u Japanu, gde se vrši i odložena obrada nakon 24 časa. Zaključak. Teorijska i praktična nastava o kompozitima u bočnoj regiji sve je češća u svetskim centrima. Potrebno je usklađivanje nastave kod nas s međunarodnim trendovima u pogledu primene koferdama, pojedinih aspekata dizajna kaviteta i protokola za lečenje dubokog karijesa.

Bij mensen met oude, verkleurde vullingen op de voortanden kan het plakken van een dun schildje, een zogeheten facing, uitkomst bieden als alternatief voor het plaatsen van een kroon. Marco Gresnigt, tandarts-onderzoeker in het Universitair Medisch Centrum Groningen, heeft dit aangetoond. Hij promoveert op 18 januari 2012 aan de Rijksuniversiteit Groningen. Uit zijn onderzoek blijkt dat het mogelijk is om facings aan te brengen na voorbehandeling van de oude vullingen, zodat het plaatsen van een kroon niet nodig is. Voor het aanbrengen van een facing hoeft minder gezond glazuur weggeslepen te worden dan bij kronen het geval is. Hierdoor is er minder kans op zenuwpijn wat prettiger is voor de patiënt. Het esthetische effect van facings is vergelijkbaar met, of soms zelfs beter, dan dat van kronen. Gresnigt promoveert op 18 januari aan de Rijksuniversiteit Groningen op dit onderzoek. Hechting Gresnigt heeft onderzoek gedaan naar de manier waarop facings gehecht kunnen worden op oude, probleemloze vullingen die niet zijn aangetast door cariës (tandbederf). Tot nu toe was het plaatsen van facings op oude vullingen niet goed mogelijk, waardoor tandartsen weinig keuze hadden dan de oude, verkleurde vullingen weg te halen of een kroon te plaatsen. Gresnigt heeft onderzocht hoe tandartsen deze (tand)oppervlakken kunnen voorbehandelen om ze geschikt te maken voor facings. Na de voorbewerking wordt een facing van composiet of porselein aangebracht en met cement vastgehecht. Facings hebben een lange levensduur; na 10 jaar is 90% van de facings nog steeds goed gehecht. Vergelijkend onderzoek Om de kwaliteit van de meest gebruikte materialen voor facings – porselein en composiet – goed met elkaar te kunnen vergelijken, heeft Gresnigt de zogenaamde “split mouth” methode toegepast. Bij de patiënten werd aan de ene kant van de mond een facing van porselein aangebracht en aan de andere kant een facing van composiet. De omstandigheden waaronder de facings met elkaar werden vergeleken

Bij mensen met oude, verkleurde vullingen op de voortanden kan het plakken van een dun schildje, een zogeheten facing, uitkomst bieden als alternatief voor het plaatsen van een kroon. Marco Gresnigt, tandarts-onderzoeker in het Universitair Medisch Centrum Groningen, heeft dit aangetoond. Hij promoveert op 18 januari 2012 aan de Rijksuniversiteit Groningen. Uit zijn onderzoek blijkt dat het mogelijk is om facings aan te brengen na voorbehandeling van de oude vullingen, zodat het plaatsen van een kroon niet nodig is. Voor het aanbrengen van een facing hoeft minder gezond glazuur weggeslepen te worden dan bij kronen het geval is. Hierdoor is er minder kans op zenuwpijn wat prettiger is voor de patiënt. Het esthetische effect van facings is vergelijkbaar met, of soms zelfs beter, dan dat van kronen. Gresnigt promoveert op 18 januari aan de Rijksuniversiteit Groningen op dit onderzoek. Hechting Gresnigt heeft onderzoek gedaan naar de manier waarop facings gehecht kunnen worden op oude, probleemloze vullingen die niet zijn aangetast door cariës (tandbederf). Tot nu toe was het plaatsen van facings op oude vullingen niet goed mogelijk, waardoor tandartsen weinig keuze hadden dan de oude, verkleurde vullingen weg te halen of een kroon te plaatsen. Gresnigt heeft onderzocht hoe tandartsen deze (tand)oppervlakken kunnen voorbehandelen om ze geschikt te maken voor facings. Na de voorbewerking wordt een facing van composiet of porselein aangebracht en met cement vastgehecht. Facings hebben een lange levensduur; na 10 jaar is 90% van de facings nog steeds goed gehecht. Vergelijkend onderzoek Om de kwaliteit van de meest gebruikte materialen voor facings – porselein en composiet – goed met elkaar te kunnen vergelijken, heeft Gresnigt de zogenaamde “split mouth” methode toegepast. Bij de patiënten werd aan de ene kant van de mond een facing van porselein aangebracht en aan de andere kant een facing van composiet. De omstandigheden waaronder de facings met elkaar werden vergeleken

This thesis presents a theoretical and experimental comparison of polymerization induced by microwave energy and polymerization induced by thermal energy of the resin bisphenol A-glycidyl methacrylate used in restorative dentistry. The question of whether microwave interaction with the polymer is microwave heating or some more involved microwave interaction with the material is addressed, as part of a general search for relative advantages and disadvantages of the two methods. Results are that the microwave energy was heating the material and that microwave energy can produce samples equal in strength to samples produced thermally with a substantial reduction of processing time.

OBJECTIVES: The present prospective, longitudinal study assessed the outcome of posterior extensive restorations and identified risk factors for failure of the restorations. MATERIALS AND METHODS: The sample consisted of 722 amalgam restorations, 115 composite resin restorations and 89 crowns placed in 428 adults by one dentist from 1982 to 1999 in Belgium. Well-defined criteria were used for cavity preparation design, type of retention and selection of restorative material. RESULTS: At the closure of the study 48% of the restorations were well functioning, 24% were lost to lack of follow-up, and 28% had failed. The most frequent reasons for failure were fracture of restoration (8%), secondary caries (6%) and fracture of cusp (5%). Failures were more often found in premolar teeth (34%) than in molars (27%) (P=0.05) and occurred in 28% of the amalgam restorations, 30% of the resin restorations and 24% of the crowns (P=0.55). Molar restorations were more frequently repaired than replaced in contrast to premolar restorations. The highest percentage of extractions was related to complete amalgam restorations in premolars. The Kaplan-Meier median survival times were 12.8 years for amalgam restorations, 7.8 years for resin restorations, and more than 14.6 years for crowns, considering all retreatment as failures (P=0.002). The survival was influenced by extension of restoration, age of patient, pulpal vitality, 3-year period of treatment, use of base material and dentinal retentive pins. CONCLUSION: Within the limits of the study the data support the view that extensive amalgam restorations but not composite resin restorations can be used as an appropriate alternative to crowns, with due consideration to the longevity of the restorations.

Stress relaxation of four temporary restoratives was studied. In the vicinity of ambient mouth temperature, the relaxation characteristics of an unmodified zinc oxide-eugenol cement were more favorable than those of IRM and Cavit. The plastic behavior of gutta-percha temporary stopping precluded assessment of its relaxation at temperatures in excess of 22P C. (Author)

Dr. Michael Buonocore, well known for his research in restorative dentistry, working in a lab at the Eastman Dental Center, 1960's.

Dental hygienists are working in the carving room of the Rochester Dental Dispensary.

Dr. Michael Buonocore in research lab with student at the Eastman Dental center, 1960's.

Dr. Michael Buonocore, well known for his research in restorative dentistry, working in a lab at the Eastman Dental Center, 1960's.

Dr. Michael Buonocore in research lab with student at the Eastman Dental center, 1960's.

Dental hygienists are working in the carving room of the Rochester Dental Dispensary.

Yamaguchi S., Lee C., Karaer O., et al. Predicting the Debonding of CAD/CAM Composite Resin Crowns with AI. Journal of Dental Research, 98(11), 1234-1238. © 2019 Sage Publications. DOI: 10.1177/0022034519867641., A preventive measure for debonding has not been established and is highly desirable to improve the survival rate of computer-aided design/computer-aided manufacturing (CAD/CAM) composite resin (CR) crowns. The aim of this study was to assess the usefulness of deep learning with a convolution neural network (CNN) method to predict the debonding probability of CAD/CAM CR crowns from 2-dimensional images captured from 3-dimensional (3D) stereolithography models of a die scanned by a 3D oral scanner. All cases of CAD/CAM CR crowns were manufactured from April 2014 to November 2015 at the Division of Prosthodontics, Osaka University Dental Hospital (Ethical Review Board at Osaka University, approval H27-E11). The data set consisted of a total of 24 cases: 12 trouble-free and 12 debonding as known labels. A total of 8,640 images were randomly divided into 6,480 training and validation images and 2,160 test images. Deep learning with a CNN method was conducted to develop a learning model to predict the debonding probability. The prediction accuracy, precision, recall, F-measure, receiver operating characteristic, and area under the curve of the learning model were assessed for the test images. Also, the mean calculation time was measured during the prediction for the test images. The prediction accuracy, precision, recall, and F-measure values of deep learning with a CNN method for the prediction of the debonding probability were 98.5%, 97.0%, 100%, and 0.985, respectively. The mean calculation time was 2 ms/step for 2,160 test images. The area under the curve was 0.998. Artificial intelligence (AI) technology—that is, the deep learning with a CNN method established in this study—demonstrated considerably good performance in terms of predicting the debonding probability of a CAD/CAM CR crown with 3D stereolithography models of a die scanned from patients.

Yamaguchi S., Lee C., Karaer O., et al. Predicting the Debonding of CAD/CAM Composite Resin Crowns with AI. Journal of Dental Research, 98(11), 1234-1238. © 2019 Sage Publications. DOI: 10.1177/0022034519867641., A preventive measure for debonding has not been established and is highly desirable to improve the survival rate of computer-aided design/computer-aided manufacturing (CAD/CAM) composite resin (CR) crowns. The aim of this study was to assess the usefulness of deep learning with a convolution neural network (CNN) method to predict the debonding probability of CAD/CAM CR crowns from 2-dimensional images captured from 3-dimensional (3D) stereolithography models of a die scanned by a 3D oral scanner. All cases of CAD/CAM CR crowns were manufactured from April 2014 to November 2015 at the Division of Prosthodontics, Osaka University Dental Hospital (Ethical Review Board at Osaka University, approval H27-E11). The data set consisted of a total of 24 cases: 12 trouble-free and 12 debonding as known labels. A total of 8,640 images were randomly divided into 6,480 training and validation images and 2,160 test images. Deep learning with a CNN method was conducted to develop a learning model to predict the debonding probability. The prediction accuracy, precision, recall, F-measure, receiver operating characteristic, and area under the curve of the learning model were assessed for the test images. Also, the mean calculation time was measured during the prediction for the test images. The prediction accuracy, precision, recall, and F-measure values of deep learning with a CNN method for the prediction of the debonding probability were 98.5%, 97.0%, 100%, and 0.985, respectively. The mean calculation time was 2 ms/step for 2,160 test images. The area under the curve was 0.998. Artificial intelligence (AI) technology—that is, the deep learning with a CNN method established in this study—demonstrated considerably good performance in terms of predicting the debonding probability of a CAD/CAM CR crown with 3D stereolithography models of a die scanned from patients.