Fabrication of guide and removal of fiber post by tetrahedron positioning technology at the chair side: a case report and literature review / 口腔疾病防治

Objective @#To explore the technology and efficacy of fabrication of a guide and removal of a fiber post by tetrahedron positioning technology at the chair side.@*Methods@# For one patient with acute chronic periapical periodontitis of the left maxillary lateral incisor who needed to have the fiber post removed, the chair side tetrahedral positioning technique was used to make a guide plate to remove the fiber post. Cone beam CT (CBCT) data were imported into the software to design the guide plate for fiber post removal. The guide plate design on CBCT was transferred to a solid model by using tetrahedral positioning technology. The guide plate was made to guide the removal of the fiber post, and then left maxillary lateral incisor root canal was performed. We evaluated the effect of fiber post removal with tetrahedral positioning technology by reviewing the literature.@*Results @#The guide plate made by tetrahedral positioning technology can accurately locate the position and direction of fiber posts at a low cost and with high speed. After the fiber post was removed, the root canal could be dredged by using root canal preparation instruments. After root canal preparation, the root canal was filled with warm gutta-percha to complete the root canal treatment. After 3 months, the apical radiograph showed that the transmission shadow of the apical area was reduced. The results of the literature review showed that the fiber post removal with guide plates provides a predictable result and a lower risk of iatrogenic damage. Minimally invasive treatment can be carried out, and chair time can be reduced.@*Conclusion@#On the basis of CBCT data, using tetrahedral positioning technology to make fiber post removal guides can help reduce the risk of fiber post removal and has the characteristics of speed, low cost and short chair side processing. However, the accuracy comparison between tetrahedral positioning technology and 3D printing guides needs further study.

A survey of the understanding of the scope of work undertaken by dental hygienists and chair-side dental assistants among dental students in Seoul / 대한구강보건학회지

OBJECTIVES: This study was conducted to investigate the awareness of the students currently attending dental colleges/schools in Seoul regarding the scope of work done by a dental hygienist (DH) and a chair-side dental assistant (DA).METHODS: A direct questionnaire survey was conducted among 950 students who currently attend dental colleges/schools in Seoul. We were able to use a total of 458 samples for final analysis after excluding inappropriate ones. The contents of this structuralized survey included the obligation of proper name badge use for dental health care personnel, the legal work scopes of a DH and a DA in accordance with the revised execution of the ‘Legal Acts on Medical Technicians’, and the inclusion/exclusion of such contents from dental colleges/schools curricula. The results were statistically analyzed via the IBM SPSS Statistics 25.0 software.RESULTS: Many subjects were aware of the difference in scope of work performed by a DH and a DA (P < 0.001), but not their legal obligation to wear appropriate name badges in accordance with the ‘Proposal for the Establishment of the Name Badge Standards for Healthcare Practitioners'. The subjects generally showed higher comprehension of the scope of work performed by a DH (74.3%) than that performed by a DA (57.7%). Without the presence of any corresponding curriculum, accurate responses tended to increase with the students' seniority. Most students (94.4%) agreed with the need to include a class that teaches the scope of work performed by a DH and a DA in their school curricula.CONCLUSIONS: We have found that education regarding ‘Name Badge Standards for Healthcare Practitioners’ and classification of a dental assistant's scope of work is lacking in the existing curriculum. Therefore, it is necessary to establish additional curriculum.

Understanding chair-side digital technology for stomatology from an engineering viewpoint / 中华口腔医学杂志

In recent years with the rapid development of digital technology for stomatology, the application field, application model, technical features and technical connotation of the chair-side digital technology has got development and change. The open modular system has gradually replaced the traditional closed system, and the application field of digital technology is no longer limited to chair-side dental restoration, it also has been extend to various kinds of chair-side digital treatment-assisted technology. In this paper, from the engineering point of view, the up to date general connotation of chair-side digital technology was explained, the characteristics and the development of each unit in chair-side digital technology were analyzed, and the application pattern and the localization status were also discussed in this paper. The aim of this paper was to introduce the trend of chair-side digital technological to readers and to better guide clinical application.

Analysis of reasons for failure of chair-side CAD/CAM ceramic restorations / 口腔疾病防治

Objective@#To investigate the failure reasons of all-ceramic restorations fabricated with chair-side CAD-CAM technology (CEREC®) and to improve the clinical survival of all-ceramic restorations. @*Methods @#All-ceramic single-tooth restorations of CEREC® in stomatology hospital of Jiangsu province between 2013 and 2016 were summarized. By clinical examination and CEREC Biogeneric surveying, the failure reasons and related restoration types were evaluated. These results were analyzed with Chi-square test and Spearman correlation analysis. @*Results@#A total of 61 cases with restoration types of 11 inlays, 38 onlays, 2 endocrowns, and 11 all-crowns, resulted in a failure rate of 5.4% in all-ceramic single-tooth restorations in 1-4 years follow-up. The reasons for failure included ceramic fracture (n=33), debonding (n=13), tooth fracture (n=15), which attributed to thin ceramic thickness (n=27), acute line angle (n=6), insufficient enamel bulk (n=3), insufficient retention type (n=10), insufficient resistance type (n=15).@*Conclusion @# The most common reason for failure in CEREC® restorations was insufficient preparation space in occlusal surface.

Clinical Study of Chair-side Immediate Ceramic Restoration Technique for Large-defected Teeth / 中国医科大学学报

Objective To explore the clinical application of digital chair?side immediate all?ceramic restoration system,design and fabricate inlays and onlays to restore the large?defected molars,and to analyze and evaluate the efficacy of this clinical restoration. Methods Totally 84 inlays and 65 onlays were fabricated with IPS e.max CAD series ceramic blocks by using Cerec AC system to conduct immediate all?ceramic restorations of 149 teeth for 108 patients. The inlays and onlays were applied and cemented to the prepared teeth with dual?cured resin luting agent. The restored molars were re?examined by two dentists after six months. The analysis standard was based on the United States Public Health Service(USPHS criteria) and the results were statistically analyzed(α=0.05). Results There was no statistically significant difference in the case numbers of grade A and grade B for each index comparing the immediate condition to the condition after 6 months. Over 90 percent of ceramic inlays and onlays were quali?fied to be grade A. The restorations were well in the aspects of anatomic morphology,marginal integrity,color match,marginal discoloration,reten?tion,gingival health and secondary caries. Conclusion Computer aided design/computer aided manufacture(CAD/CAM)system combined with machinable glass ceramics can achieve a favorable result in restoration of large?defected teeth. Digital chair?side immediate all?ceramic restoration technique is an ideal solution for large?defected tooth restoration.

Evaluation of linear dimensional accuracy of hard chairside and laboratory heat cure reline resins at different time intervals after processing.

Context: Relining with heat cure denture base resin is time‑consuming and the patient has to remain without dentures within this period. Recently, some autopolymerizing resins marketed as hard chairside reline systems with low exothermic heat allow the dentists to reline prosthesis directly in the mouth. However, the decision to use these materials must be based on physical properties such as dimensional accuracy that directly influences the accuracy of fit of the denture base. Aim: The aim was to compare the linear dimensional changes of two hard chairside reline resins with two laboratory heat cure resins at 3 times intervals after processing. Settings and Design: A stainless steel split mold (International Organization for Standardization 1567) was used for sample fabrication. Five measurements of the reference dimensions (AB and CD) were measured directly from the mold and the samples with a profile projector, and mean difference were calculated. Subjects and Methods: Forty samples were fabricated by incorporating the split mold into first pour of denture flasks and packing each of the chairside reline resins (“Kooliner” and “Ufi Gel Hard”) and laboratory heat cure resins (“Dental Products of India Heat Cure” and “Trevalon”). The mean difference in dimensional change at 3 times intervals (0 h, 4 days and 2 months) were calculated and subjected to statistical analysis. Statistical Analysis Used: One‑way ANOVA, RMANOVA and post hoc Tukey’s tests. Results: All resins showed different levels of significant shrinkage (P < 0.001) after processing (T0) ranging from −0.128 to −0.310 mm. After 4 days (T1), there was significant shrinkage (P < 0.001) ranging from −0.168 to −0.296 mm. After 2 months (T2), there was again significant shrinkage (P < 0.001) ranging from −0.018 to −0.216 mm. Chairside reline resins showed less dimensional shrinkage at each time interval than the laboratory heat cure resins. Conclusions: Hard chairside resins are dimensionally accurate than the laboratory heat cure resins.

Análisis de MMPs en fluidos orales en el diagnóstico complementario de las enfermedades periodontales / Oral-fluid MMP analysis in the complementary diagnosis of periodontal diseases

La periodontitis constituye la infección bacteriana más prevalente a nivel mundial y representa un factor de riesgo para diversas patologías sistémicas. El estado de inflamación y destrucción periodontal se manifiestan a través de la presencia de biomarcadores en el suero y fluidos orales, tales como el fluido gingival crevicular (FGC), saliva y enjuague oral. Enzimas como las metaloproteinasas de matriz (MMP) y mieloperoxidasa, constituyen biomarcadores potenciales para ensayos moleculares complementarios a la clínica de uso en el sillón dental. A continuación se presenta una revisión de la literatura respecto de la aplicación potencial del análisis de metaloproteinasas de matriz extracelular (MMPs) en el diagnóstico complementario de las enfermedades periodontales. Se ha demostrado que los niveles de MMP-9, -13 y particularmente de MMP-8, se asocian con el grado de inflamación periodontal, y pueden diferenciar entre sujetos sanos, con gingivitis, periodontitis y peri-implantitis, mientras que la mejoría de los parámetros clínicos en respuesta al tratamiento periodontal se asocia con la reducción de la activación y niveles de estas enzimas en FGC, como así también en el suero. Se concluye que la determinación, particularmente de MMP-8 en fluidos orales presenta un elevado potencial como complemento de los métodos clínicos tradicionales para identificar a los pacientes con periodontitis o en riesgo de desarrollar la enfermedad, monitorear fases del tratamiento y mejoría de signos periodontales e incluso evaluar el estado de inflamación sistémica.

Periodontal disease is the most common bacterial infection worldwide and it can contribute to enhance the risk for the development of several systemic diseases. The status of periodontal inflammation and destruction can be reflected in biomarker measurement in serum and oral fluids, like gingival crevicular fluid (GCF), saliva and mouth-rinse. Some enzymes, such as matrix metalloproteinases (MMPs) and myeloperoxidase are potential candidates for chair-side point-of-care oral fluid assays. This review is focused on the utility of matrix metalloproteinase (MMP) analysis in oral fluid as a complementary diagnostic method to chronic periodontitis. Levels of MMP-9,-13 and specially of MMP-8, reflect oral inflammatory status and discriminate among healthy, gingivitis, periodontitis and periimplantitis individuals, whereas MMP levels and activation in GCF and serum are in line with the improvement of clinical parameters in response to periodontal treatment. As a conclusion, MMP-8 assessment in GCF could represent a helpful adjunctive method to traditional diagnostics to identify periodontitis or patients at risk to develop the disease, monitor treatment phases, improvement of periodontal signs and even screen the systemic inflammation status.

Evaluation of efficiency of manual polishing over autoglazed and overglazed porcelain and its effect on plaque accumulation

PURPOSE: The aim of this study was to evaluate the efficiency of manual polishing over autoglazed and overglazed porcelain and their effect on plaque accumulation. MATERIALS AND METHODS: Thirty-six porcelain discs were fabricated out of which 18 each was subjected for autoglazing and overglazing. Half surface of the discs was left intact; the remaining half was roughened with medium grit diamond bur. Roughened surfaces were repolished by porcelain polishing kits (Shofu, DFS, Eve). All the surfaces were evaluated by the perthometer and SEM. Six discs from each sample were placed in human volunteer's mouth for 72 hours to evaluate the plaque accumulation. Acquired data was subjected to ANOVA comparative evaluation. RESULTS: Roughened surfaces had average roughness value of 2.88+/-0.1935 microm. The repolished surfaces by porcelain correction kits Shofu, DFS and Eve, average roughness value reduced to 0.6250+/-0.1036, 0.9192+/-0.0953, 0.9017+/-0.1305 respectively. Autoglazed and overglazed surfaces showed the mean roughness value (Ra) of 0.4217+/-0.0685, 0.3450+/-0.0729. SEM study showed the improved surfaces when subjected for polishing. Plaque accumulation percentage was the highest on roughened surface (93.83+/-6.2552%), followed by porcelain discs polished by commercial kits. Autoglazed surfaces found to be the best surfaces with the least plaque accumulation (0.5237+/-0.4209%). CONCLUSION: All the polishing kits used in the study reduced the average roughness by approximately 77%. Corrected porcelain surfaces should ideally be reglazed, alternatively, polish the surfaces before final cementation.