Longevity of anterior resin-bonded bridges: survival rates of two tooth preparation designs.

BACKGROUND: Significant developments have occurred in the design of resin-bonded bridges (RBB) over the past two decades. They are commonly used as an alternative treatment option for a single missing tooth. The longevity of these bridges needs to be further investigated to evaluate long-term outcomes for this option to remain relevant. METHODS: A cohort of patients who received anterior resin-bonded bridges (ARBB) over two decades was studied retrospectively. Longevity of 206 ARBB was assessed using Kaplan-Meier probability estimates. The two modified tooth preparation designs investigated were: (A) mesial and distal vertical grooves only; and (B) one proximal groove adjacent to the pontic and two palatal grooves. Age and gender of the patient cohort were also recorded. RESULTS: Overall survival rate of ARBB was 98% at 5 years, 97.2% at 10 years, and 95.1% from 12 years till 21 years. Survival curves showed minor differences when compared for the two designs, age groups and gender of ARBB recipients. Differences in the proportion of surviving bridges for design A (95.96%) and design B (98.13%) were not statistically significant (Fisher's exact test). CONCLUSIONS: Anterior RBB with described tooth preparation designs demonstrate a high survival rate.

Targeted Therapy and Immunotherapy Response Assessment with F-18 Fluorothymidine Positron-Emission Tomography/Magnetic Resonance Imaging in Melanoma Brain Metastasis: A Pilot Study.

INTRODUCTION: This pilot study aimed at exploring the utility of the proliferation tracer F-18 fluorothymidine (FLT) and positron-emission tomography (PET)/magnetic resonance imaging (MRI) (FLT-PET/MRI) for early treatment monitoring in patients with melanoma brain metastasis (MBM) who undergo targeted therapy or immunotherapy. MATERIAL AND METHODS: Patients with newly diagnosed MBM underwent baseline and follow-up FLT-PET/MRI scans at 3-4 weeks of targeted therapy or immunotherapy. Up to six measurable brain lesions ≥1.0 cm per subject, as identified on T1-weighted post-gadolinium images, were included for quantitative analyses. The maximum SUV of each lesion was divided by the mean SUV of the pons to obtain the SUV ratio (SUVR). RESULTS: Five enrolled subjects underwent the baseline FLT-PET/MRI study in which the MBM showed a median size of 1.7 cm (range 1.0-2.9) and increased metabolic activity with SUVR of 9.9 (range 3.2-18.4). However, only two subjects (cases #1 and #2) returned for a follow-up scan. At baseline, a total of 22 lesions were analyzed in all five subjects, which showed a median size of 1.7 cm (range 1.0-2.9) and median SUVR of 9.9 (range 3.2-18.4). At follow-up, case #1 was a 55-year-old man who received targeted BRAF inhibitor and MEK inhibitor therapy with dabrafenib and trametinib. Fused PET/MRI data of six measured lesions demonstrated a significant reduction in MBM proliferative activity (median -68%; range -38 to -77%) and size (median -23%; range -4 to -55%) at three weeks of therapy. Nevertheless, the subject eventually progressed and died 13 months after therapy initiation. Case #2 was a 36-year-old man who received immunotherapy with nivolumab and ipilimumab. The five measured MBM lesions showed a mixed response at both proliferative and morphologic imaging at 1-month follow-up. Some lesions demonstrated interval decrease while others interval increase in proliferative activity with a median -44% (range -77 to +68%). On MRI, the size change was +7% (range -64 to +50%). The therapy was switched to dabrafenib and trametinib, which led to a partial response. The patient is still alive 16 months following therapy initiation. CONCLUSION: The five cases presented show the potential benefit of hybrid FLT-PET/MRI for the diagnosis of MBM and treatment monitoring of targeted therapy and immunotherapy. However, further studies are required to assess their complementary role in distinguishing true progression from pseudoprogression.

Educating medical students in oral health care: current curriculum and future needs of institutions in Malaysia and Australia.

Poor oral health has been associated with compromised general health and quality of life. To promote comprehensive patient management, the role of medical professionals in oral health maintenance is compelling, thus indicating the need for educational preparation in this area of practice. This study aimed to determine the extent of training in oral health in Malaysian and Australian medical schools. An audio-recorded semi-structured phone interview involving Academic Programme Directors in Malaysian (n = 9, response rate=81.8%) and Australian (n = 7, response rate = 35.0%) medical schools was conducted during the 2014/2015 and 2014 academic years, respectively. Qualitative data was analysed via thematic analysis, involving coding and grouping into emerging themes. Quantitative data were measured for frequencies. It was found that medical schools in Malaysia and Australia offered limited teaching of various oral health-related components that were mostly integrated throughout the curriculum, in the absence of structured learning objectives, teaching methodologies and assessment approaches. Barriers to providing oral health education included having insufficient expertise and overloaded curriculum. As medical educators demonstrated support for oral health education, collaboration amongst various stakeholders is integral to developing a well-structured curriculum and practice guidelines on oral health management involving medical professionals.

The shortened dental arch concept: awareness and opinion of dentists in Victoria, Australia.

BACKGROUND: The occlusion of a complete dental arch is generally desirable but not necessary nor always achievable in many individuals. It is, however, relevant for dentists to consider what minimum number of teeth is required by individuals for oral function. This study investigated dentists' awareness and opinion of the shortened dental arch (SDA) concept in an Australian context. METHODS: A self-administered voluntary and anonymous questionnaire was mailed to a sample of 434 dentists, randomly selected from both rural and metropolitan locations in Victoria, Australia. The information collected included awareness of the SDA concept and its application as a treatment option. RESULTS: More than half of the respondents (61%) were aware of the SDA concept. All respondents 'agreed' or 'strongly agreed' with the seven criteria of SDA proposed in this study based on Käyser (1989). The majority (78.4%) believed that the SDA concept is useful in clinical practice. Dentists with <20 years of experience expressed more awareness compared to others (χ(2) test, p = 0.004). CONCLUSIONS: Most dentists who responded to this survey agreed that the SDA is a practical and useful treatment modality for older adults with limitations to complex restorative care. However, application of the SDA varied considerably among dentists.

Fracture patterns of glass-ionomer cement overlays versus stainless steel bands during endodontic treatment: an ex-vivo study.

AIM: To compare fracture patterns of posterior teeth temporized with: mesio-occlusal-distal (MOD) glass-ionomer cement (GIC) interim restorations, stainless steel (SS) bands, GIC dome overlays and GIC dome overlays with occlusal temporary restorations. METHODOLOGY: The root canals of 92 extracted human premolars and molars were prepared with rotary NiTi instruments and dressed with calcium hydroxide paste prior to cavity preparation for standardized MOD restorations. Teeth were divided into four groups (n = 23) and temporarily restored with: GIC interim restorations (GIC group), stainless steel bands (SS group), GIC dome overlays (GIC-O group) or GIC dome overlays with intermediate restorative material (IRM) in the access cavities (GIC-IRM group). Teeth were subjected to compressive axial load until fracture; fracture forces and fracture modes were recorded. Statistical analysis included Kaplan-Meier plots, Cox proportional hazards model, one-way analysis of variance, chi-square and Fisher's exact tests. RESULTS: There was a significantly higher risk of failure in the GIC group compared with the SS (P < 0.001), GIC-O (P < 0.001) and GIC-IRM (P = 0.001) groups. The mean fracture force for SS was significantly higher than GIC-O (P = 0.03) and GIC-IRM (P < 0.001). GIC fracture force was significantly lower than all other groups (P < 0.001). Significantly fewer unfavourable fractures were observed in SS compared with GIC (P = 0.001), GIC-O (P = 0.007) and GIC-IRM (P < 0.001). CONCLUSIONS: Glass-ionomer cement dome overlays with reduced cuspal height and occlusal inclines may be recommended for broken-down posterior teeth, without any risk of poor aesthetics, gingival irritation or further proximal tooth structure loss. Stainless steel bands may only need to be used in extensively broken-down teeth or in the presence of parafunctional habits.

Development of a rural outplacement programme for dental undergraduates: students' perceptions.

OBJECTIVES: To describe the development and implementation of a new rural dental outplacement module in the final year curriculum and report initial student perceptions. METHODS: The Melbourne Dental School, University of Melbourne, introduced a required 4-week rural outplacement [termed Rural Dental Rotation (RDR)] in July 2006 to provide education and clinical training to all final year students. Seventy dental students (Bachelor of Dental Science and Bachelor of Oral Health) were rostered in groups of 6-10 students to Shepparton (Victoria, Australia), from July 2006 to June 2007 for 4 weeks per group. Students were introduced to the culture and oral health needs of the indigenous population in the region, and were involved in oral health promotion in specific health programmes. At the end of each roster students provided feedback of their experiences through a voluntary anonymous questionnaire. RESULTS: The RDR offered a rural learning experience to all final year dental undergraduates and also provided dental services to the local community on a continuing basis. Students agreed that the RDR was a worthwhile experience (mean 4.77 +/- 0.46 on 1-5 scale) and was 'enjoyable' (mean 4.71 +/- 0.45). There was only one student who did not consider rural practice in future. This was because of family reasons. The majority (79.1%) expressed definite affirmation, whereas some (19.4%) indicated the possibility of taking up rural practice. CONCLUSIONS: Overall feedback indicated that the students found it a very positive and enjoyable experience. It provided an opportunity to appreciate cultural safety and understand the specific oral health needs of indigenous Australians. The key benefit of such a programme to the community is the increased likelihood of attracting new dental graduates to rural areas.

Effect of denture thickness on tooth movement during processing of complete dentures.

In this investigation the effect of denture thickness on tooth movement during processing of complete dentures was studied. A maxillary cast from a patient was duplicated to obtain 10 identical casts. Base plates were constructed on five casts using 1.25 mm thick wax. Base plates were constructed on the other five casts using 2.5 mm thick wax. Teeth were placed on the ridge of each cast and a TMS pin was placed vertically, upright, in each tooth. The dentures were invested, cured, decasted, finished and polished. Each denture was radiographed immediately before processing, after deflasking, on removal from the cast and after finishing and polishing using a standard technique. The radiographs were digitized using an Eikonix image digitizer. The results showed that there were significant variations in tooth movement between thick and thin denture bases. Also an increase in the molar-to-molar distance was found in both the thin and thick dentures but the magnitude of tooth movement was more in thick dentures.

Tooth movement during processing of complete dentures and its relation to palatal form.

Tooth movement during processing of acrylic resin complete dentures was investigated in relation to palatal form. Eleven clinical casts were radiographed at four denture-processing stages. Seven points were located across each cast. Radiographs were digitized and the images obtained were processed and analyzed for precise measurement of tooth movement. A palatal form index was developed. With respect to a relationship between tooth movement and palatal form, certain trends were found with varying degree and direction, shedding light on the behavior of base material and the dimensional changes that occurred during processing.