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The population is ageing and people are keeping their own teeth for much longer due in part to the efforts of the dental profession in restoring teeth and reducing the number of teeth being extracted. Along with this there is now an increasing expectation by patients that they will retain their own teeth as they age and that dental practitioners will have the knowledge and skills to help them retain their own teeth. Contemporary restorative materials and techniques have increased the range of options available to assist with maintaining the dentition, and many of these procedures enable minimally invasive and cost effective management of the teeth as an alternative to complex and expensive procedures. This paper discusses the restoration of compromised and failing teeth in the ageing patient, and looks at the various issues facing the ageing dentate patient and the dilemma of when to restore or when to extract. Ultimately it is hoped that maintaining healthy teeth for life may not only improve oral function and quality of life, but may in fact reduce the impact of the physical and psychological aspects of ageing. [ABSTRACT FROM AUTHOR]

Fissure sealants have been used successfully as a means of preventing fissure caries. This effectiveness is directly related to sealant retention and retention is dependent upon a meticulous method of application. The aims of this study were to determine if sealant adhesion and penetration were affected by the variation in preparation of the enamel surface, or by pretreatment of the enamel surface with dentine adhesive systems, in fissures of varying morphology. Non-carious posterior teeth were visually examined and sorted according to fissure type, classified as shallow, deep or intermediate. Occlusal fissures were sealed using one of six methods, thermocycled for 200 cycles between 5 and 55°C, in artificial saliva, then placed in a 1.5% procion orange dye for 3 min. Teeth were sectioned bucco-lingually and examined with a light microscope for (1) penetration of the sealant into the fissure pattern and (ii) adhesion of the sealant. All sealant techniques employed in this study adapted well to the enamel surface as the 1.5% procion Reactive orange dye failed to penetrate any of the sealed tooth sections. Shallow fissures were well obturated in both lateral and vertical dimensions. Sealants adapted well to the vertical walls at the orifice of deep fissures but generally failed to penetrate into the deeper aspects. Reducing the etching period with 37% phosphoric acid resulted in increased voids between the sealant and enamel surface and poorer adaptation to the vertical walls. The addition of dentine adhesive systems, Scotchbond Multi-Purpose and All-Bond 2, enhanced the vertical penetration of the sealant, particularly in deep fissures. It is proposed that the dentine adhesive systems may improve the retention rate of sealants in deep fissures particularly if the fissure is not completely dry prior to resin placement. [ABSTRACT FROM AUTHOR]

The article discusses the importance of field work in elementary education. The author argues that interrelation of the children with their natural and social environment is an important part of their educational process . Subjects of study in field work is given such as topography, physiography and vegetation. An outline of preparation for teaching in field study is also given. He also suggests that field work for kindergarten and primary grades should also be done such as visits to various types of areas in the region. The author implies that curiosity and desire for learning of children are manifested when they are experiencing the outdoors and schools need to promote field work to strengthen the contact of students with his environment.

A 19-year-old male was referred to the School of Dentistry, University of Queensland for management and treatment of uncontrolled root caries. A total of 12 teeth had non-cavitated root carious lesions requiring treatment. The lesions were treated with a daily application of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP; GC Tooth Mousse) and in-surgery photo-activated disinfection (PAD). Laser fluorescence (KaVo Diagnodent) was used to monitor the changes in the carious lesions. The combination of CPP-ACP and PAD proved to be very effective and holds great potential as a recommended treatment for stabilising root surface caries in the clinical practice. [ABSTRACT FROM AUTHOR]

Aim: This descriptive epidemiological study aimed to quantify the incidence, characteristics and costs of head, neck and dental injuries in non-professional football players., Methods: Injury data were coded (using Orchard Sports Injury and Illness Classification System) from a de-identified insurance database containing three seasons (2018-2020) of data. Cost data included direct and indirect costs presented by type of injury, age group and sex using means ± SD, range of costs ($AU) and total costs ± SE. Chi-squared tests were used to analyse the data (significance level p < .05) with injury incidence rates (IR) calculated per 1000 match hours and per 1000 injury insurance claims., Results: A total of 388 injuries affecting 240 players were sustained. Of these, 43% (n = 102) of players also sustained one or more secondary injuries, mainly to the head or neck area. Dental injuries (n = 143, 39%, IR = 0.008) accounted for the highest number of primary and secondary injuries and the highest mean direct cost per injury ($AU1152), while head and facial injuries accounted for the highest proportion of total costs ($AU434,101). Players who sustained one or more secondary injuries had the highest direct and indirect mean cost per injury., Conclusions: Given the frequency and cost of dental injuries in non-professional football players, injury prevention initiatives warrant further investigation., (© 2023 The Authors. Dental Traumatology published by John Wiley & Sons Ltd.)

The treatment of glioblastoma (GBM) remains challenging in part due to the presence of stem-like tumor-propagating cells that are resistant to standard therapies consisting of radiation and temozolomide. Among the novel and targeted agents under evaluation for the treatment of GBM are BRAF/MAPK inhibitors, but their effects on tumor-propagating cells are unclear. Here, we characterized the behaviors of CD133(+) tumor-propagating cells isolated from primary GBM cell lines. We show that CD133(+) cells exhibited decreased sensitivity to the antiproliferative effects of BRAF/MAPK inhibition compared to CD133(-) cells. Furthermore, CD133(+) cells exhibited an extended G2-M phase and increased polarized asymmetric cell divisions. At the molecular level, we observed that polo-like kinase (PLK) 1 activity was elevated in CD133(+) cells, prompting our investigation of BRAF/PLK1 combination treatment effects in an orthotopic GBM xenograft model. Combined inhibition of BRAF and PLK1 resulted in significantly greater antiproliferative and proapoptotic effects beyond those achieved by monotherapy (P < 0.05). We propose that PLK1 activity controls a polarity checkpoint and compensates for BRAF/MAPK inhibition in CD133(+) cells, suggesting the need for concurrent PLK1 inhibition to improve antitumor activity against a therapy-resistant cell compartment., (©2015 American Association for Cancer Research.)

The management of patients with extensively worn and badly broken down dentitions presents a difficult challenge in dental practice and restorative treatments are often complex, time consuming and costly to implement, so careful case selection and treatment planning is essential. Ultimately the success of any restorative intervention is very dependent on the stability of the oral environment and the status of the remaining tooth structure. Prior to the commencement of any restorative treatment an understanding of the importance of the disease process, the risk factors in the mouth, and the intrinsic and extrinsic factors which affect the oral balance is critical. While there is a growing range of materials and techniques available for cost effective and conservative management of these cases, failure to take a systematic approach to assessment and stabilization may result in early restorative failure, rapid recurrence of the problems and a repeat restoration cycle. Therefore successful management of these patients must include an appropriate mix of preventive and restorative strategies.

Objectives: To compare curing performance of a second generation LED curing light with a high power tungsten quartz halogen (QTH)., Methods: A hybrid composite resin (Filtek Z 250, 3M, USA) was used as test material and cured using a second generation LED light (Translux Power Blue™, Heraus Kulzer ,Germany) or a very high power QTH light unit (EMS, Switzerland). A two split aluminum mold was used to prepare ten samples with LED light source cured for forty seconds and ten samples prepared using high power QTH light unit, cured for four or six seconds recommended exposure time. Hardness, depth of cure (DOC) and thermal rise during exposure time by these light sources were measured. The data submitted to analysis of variance (ANOVA), Tukey's and student's t tests at 5% significance level., Results: Significant differences were found in hardness, DOC of samples cured by above mentioned light sources and also in thermal rises during exposure time. The curing performance of the tested QTH was not as well as the LED light. TPB light source produced the maximum hardness (81.25, 73.29, 65.49,55.83 and 24.53 for 0 mm, 1 mm, 2 mm, 3 mm and 4 mm intervals) and DOC (2.64 mm) values with forty seconds irradiation time and the high power (QTH) the least hardness (73.27, 61.51 and 31.59 for 0 mm, 1 mm and 2 mm, respectively) and DOC (2 mm) values with four seconds irradiation time. Thermal rises during 4 s and 6 s curing time using high power QTH and tested LED were 1.88°C, 3°C and 1.87°C, respectively., Conclusions: The used high power LED light produced greater hardness and depth of cure during forty seconds exposure time compared to high power QTH light with four or six seconds curing time. Thermal rise during 6 s curing time with QTH was greater compared to thermal changes occurred during 40 s curing time with tested LED light source. There was no difference seen in thermal changes caused by LED light with 40 s and QTH light with 4 s exposure time.

Background and Aims: The aim of the present study was to compare the efficacy of quartz tungsten halogen (QTH) and light emitting diode (LED) curing lights on polymerization of resin composite., Materials and Methods: A hybrid resin composite was used to prepare samples which were cured using two QTH and ten LED light curing sources. Twelve groups, each containing ten samples, were prepared using each light source. The cured depth of the resin was determined using ISO 4049 method and Vickers hardness values were determined at 1.0 mm intervals. Data was analyzed by ANOVA and Tukey test., Results: Data analysis demonstrated a significant difference between light sources for depth of cure. At 1.0 mm below the surface all the tested light sources and at 2.0-mm intervals all light sources except two (Optilux 501 and LEDemetron I) and at 3.0-mm intervals only two light sources (PenCure and LEDemetron II) could produce hardness values higher than 80% of superficial layer values., Conclusion: This study showed that a variety of LED light sources used in the present study are as effective as the high-intensity QTH lights in polymerization of resin composite.

Background: This study aimed to determine the reasons for dentists' choice of materials, in particular amalgam and resin composite, in Australia., Method: A questionnaire was developed to elicit this information. The names and addresses of 1000 dentists in Australia were selected at random. The questionnaire was mailed to these dentists with an explanatory letter and reply-paid envelope., Results: A total of 560 replies were received. Regarding choice of material, 99 per cent of respondents cited clinical indication as an influencing factor, although patients' aesthetic demands (99 per cent of respondents), patients' wish (96 per cent), patients' financial situation (82 per cent), and lecturers' suggestions (72 per cent) were also reported to influence respondents' choice of materials. Twelve per cent of respondents used composite 'always', 29 per cent 'often', 32 per cent 'sometimes', 23 per cent 'seldom' and 4 per cent 'never' in extensive load-bearing cavities in molar teeth. For composite restorations in posterior teeth, 84 per cent 'always', 'often' or 'sometimes' used the total etch technique, 84 per cent used a thick glass-ionomer layer and 36 per cent never used rubber dam. Fifty-nine per cent of respondents reported a decreased use of amalgam over the previous five years. Sixty-eight per cent of respondents agreed with the statement 'discontinuation of amalgam restricts a dentist's ability to adequately treat patients'. Seventy-five per cent considered that the growth in the use of composites increased the total cost of oral health care., Conclusions: Of the respondents from Australia 73 per cent place large composite restorations in molar teeth and their choice of material is influenced greatly by clinical indications, and patients' aesthetic demands.

Composite resin is a widely-used direct tooth coloured restorative material. Photoactivation of the polymerisation reaction can be achieved by visible blue light from a range of light sources, including halogen lamps, metal halide lamps, plasma arc lamps, and Light Emitting Diode (LED) lights. Concerns have been raised that curing lights may induce a temperature rise that could be detrimental to the vitality of the dental pulp during the act of photoactivation. The present study examined heat changes associated with standardised class V restorations on the buccal surface of extracted premolar teeth, using a curing time of 40 seconds. The independent effects of type of light source, resin shade, and remaining tooth thickness were assessed using a matrix experimental design. When a conventional halogen lamp, a metal halide lamp and two different LED lights were compared, it was found that both LED lamps elicited minimal thermal changes at the level of the dental pulp, whereas the halogen lamp induced greater changes, and the metal halide lamp caused the greatest thermal insult of all the light sources. These thermal changes were influenced by resin shade, with different patterns for LED versus halogen or halide sources. Thermal stress reduced as the remaining thickness of tooth structure between the pulp and the cavity floor increased. From these results, it is concluded that LED lights produce the least thermal insult during photopolymerisation of composite resins.

This study examined the effect of a nightguard vital bleaching procedure on enamel surface morphology and the shear bond strength of a composite resin luting cement to enamel. Extracted human teeth were bleached for 1 week using a vital bleaching product. Control teeth were brushed with a fluoride toothpaste and processed similarly to the bleached teeth, however the bleaching product was substituted with artificial saliva in the night guards. Teeth were stored in artificial saliva for 24 h, 1, 6 or 12 weeks and then examined for any surface changes using light and scanning electron microscopy. The effect of etching surfaces with 37% phosphoric acid was examined at the scanning electron microscope level. The shear bond strength of composite resin luting cement to both buccal and lingual surfaces of bleached and control teeth was determined. Light microscopy investigation suggested the bleaching process resulted in a loss of mineral from enamel which was evident 24 h after bleaching and was sustained following 12 weeks storage in artificial saliva. Scanning electron microscopy showed a definite change in the surface texture of the bleached enamel surface. Acid etching of the bleached enamel surface produced loss of prismatic form and the enamel appeared overetched. The mean shear bond strength between composite resin luting cement and etched enamel tended to be lower for bleached enamel surfaces, however no significant difference in shear bond strength was noted between control and experimental groups. The results of this study suggest that bleaching resulted in changes to the surface and subsurface layers of enamel. Although surface changes were observed in the etched enamel, the shear bond strength of composite resin luting cement to etched bleached enamel appeared to be clinically acceptable.

Physiological root resorption of primary molars was assessed using bitewings and orthopantomograms. Thirty-six per cent of teeth examined demonstrated reduced root resorption of one or more roots. Excepting the lower first primary molar, the present study recorded a relatively high incidence of uneven root resorption during the exfoliative process, particularly evident for the upper second primary molar. Discrepancy in size between the premolar and its predecessor, as well as the position of the developing permanent tooth in relation to primary root structure influences the pattern of root resorption. Therefore, constant monitoring of teeth demonstrating uneven resorption is required to avoid the complications associated with over-retained teeth.

The purpose of this study was to investigate the incidence of pulpal floor damage caused by operator error in a standard pulpotomy exercise, and to determine if this damage produced significant changes in dentin morphology and thickness at the base of the pulp chamber. One hundred and fourteen primary molar teeth were utilized in this study, 61 having pulpotomies and the remainder untreated. The dentin thickness in the furcation was measured on all the teeth and the pulpal floor morphology was examined using both light and scanning electron microscopy. The difference in thickness of dentin in the furcation of pulpotomized and non-pulpotomized teeth was not statistically significant. Less than fourteen per cent of pulpotomized teeth showed damage to the pulpal floor and this damage was only minimal in all cases. This study therefore suggests that damage to the pulpal floor during preparation is unlikely to be a factor contributing to failure of pulpotomies.

The ability of glass ionomer linings to aid in the prevention of microleakage under Class V composite resin restorations has been investigated. A conventional glass ionomer lining (Ketac-bond) and two light cured linings (Vitrabond and Timeline) were evaluated with respect to their ability to reduce microleakage. Seventy two Class V cavities were restored either by a bulk fill or incremental fill technique, and following restoration, half the teeth were thermocycled in artificial saliva. Dye penetration, using a Procion orange dye was recorded along the gingival dentine wall and at the occlusal enamel margin for all teeth. The results showed significant differences in leakage along the gingival dentine wall between the various linings under all conditions. Vitrabond produced significantly less leakage than Ketac bond which in turn produced significantly less leakage than Timeline. Significant differences in microleakage were noted between the thermocycled and non-thermocycled groups. Little or no significant differences in leakage were shown between the bulk filled and incremental filled teeth.