A comparative in vitro analysis of various temporization materials with respect to pulp chamber temperature changes during polymerization.

AIM: (1) To compare the temperature rise in the pulp chamber with different resin materials used for making provisional fixed partial dentures in anterior and posterior region while using Polyvinylsiloxane impression materials as matrix. (2) To identify a superior provisionalization material based on the amount of heat dissipated suitable for anterior and posterior provisional fixed partial denture fabrication. SETTINGS AND DESIGN: Temporary crowns and bridges are integral to Fixed Prosthodontics. It has been observed that conventional fixed prosthesis temporisation materials release heat due to the exothermic polymerisation reaction. When such a provisional material is directly let to set on a vital tooth, the heat transfer causes irreversible changes in the pulp tissue depending of the degree of change. Hence, this study observes amount of heat generation in various materials during temporisation procedure, by simulating similar conditions. MATERIALS AND METHODS: Two Models were fabricated, one simulating missing lateral incisor (Model A) and another simulating missing first molar (Model B). Intact maxillary central incisors and canine for Model A and intact mandibular Second Premolar and Second Molar were selected to act as abutments. These abutment teeth were fitted with the tip of a K-type Thermocouple inside their pulp chambers and these were connected to a digital thermometer. Five temporisation materials were chosen for fabrication of temporary crowns through Direct technique. (1) polymethy methacrylate (Self Cure acrylic), (2) bisacryl composite (Protemp 4), (3) visible light cure urethane dimethacrylate (Revotec LC), (4) barium glass and fumed silica infused methacrylate (Dentsply Integrity) and (5)nano-hybrid composite (VOCO Structur 3). Ten observations were made for each provisional material on each model. During each observation, temperature rise was recorded at 30s interval from the time of application, through the peak and till a decrease in temperature is observed. Polyvinyl siloxane was used as matrix for all except light cure resin, where polypropylene sheet was used. STATISTICAL ANALYSIS USED: Anova test used for statistical. RESULTS: ANOVA test revealed that there was a significant difference in the temperature changes associated with the provisional restorative materials used. Among the five, polymethy methacrylate (self cure resin) showed the maximum rise in temperature, followed by bisacryl composite (Protemp 4), visible light cure urethane dimethacrylate (Revotec LC), barium glass and fumed silica infused methacrylate (Dentsply Integrity) and nano-hybrid composite (VOCO Structur 3). There was no comparable difference between Model A and B but an overall reduction of temperature rise was observed in model B. CONCLUSION: VOCO Structur 3 showed the least temperature rise in the pulp chamber, and overall temperature rise was less for model B which can be attributed to the residual dentin thickness.

Screening for cognitive impairment in an Australian aged care assessment team as part of comprehensive geriatric assessment.

Accurate detection of mild cognitive impairment (MCI) is important to stratify and address risk. Yet, few short cognitive screening instruments are validated for this. . In Australia, all clients referred to an Aged Care Assessment Team (ACAT) receive comprehensive geriatric assessment (CGA) including the Standardized Mini-Mental State Examination (SMMSE). We compared the accuracy of the quick mild cognitive impairment (Qmci) screen to the SMMSE in 283 participants: 195 with dementia, 47 with MCI, and 41 with subjective cognitive decline (SCD) in an Australian community-based ACAT. Both had similar accuracy in identifying dementia, AUC of 0.86 for the Qmci versus 0.93 for the SMMSE (p = 0.10), but the Qmci was more accurate than the SMMSE in differentiating MCI from SCD, AUC of 0.84 versus 0.71, respectively, p = 0.046. These suggest that the new, short (3-5 min) Qmci screenis appropriate for use in an ACAT or other units conducting CGA.

Effectiveness of 'rehabilitation in the home' service.

OBJECTIVES: Rehabilitation in the home (RITH) services increasingly provide hospital substitution services. This study examines clinical outcomes in a large metropolitan RITH service in Western Australia. METHODS: The 2010 database of Fremantle Hospital RITH service was interrogated to identify the clinical profile of cases, length of stay (LOS) and clinical outcomes. Negative outcomes included death or unexpected hospital readmission. Multiple logistic regression modelling was used to explore associations with negative outcomes. This study was reviewed by the Institutional Review Board which deemed it not to require ethics approval. RESULTS: There were 1348 cases managed by RITH: 70.6% were aged≥65 years; elective joint replacement (29.7%), medical conditions (20%), stroke (13%), hip fractures (10%) were major contributors. The majority (93.3%) were discharged after a median of 9 days. Negative outcomes occurred in 90 cases (6.7%), including five deaths (0.4%) and 85 readmissions (6.3%). Independent associations with negative outcomes included older age (odds ratio (OR) (95% CI); 1.02, P=0.006), orthopaedic conditions (OR 1.91, P=0.004) and longer inpatient LOS (OR 1.96, P=0.003). Age above 80 years was independently associated with risk of negative outcome (OR 2.99, P=0.004). CONCLUSIONS: RITH had a low rate of negative outcomes. The database proved useful for monitoring quality of service provision. WHAT IS KNOWN ABOUT THE TOPIC?: Rehabilitation in the home environment has proven cost effective for multiple conditions, particularly stroke and elective joint surgery, among others, facilitating better quality of life, with reduced rates of delirium and mortality. Overall there are few negative outcomes and death is rare. WHAT DOES THIS PAPER ADD?: Although RITH services are widely utilised as bed substitution services, there is scant literature on clinical outcomes while within the service. This study focuses on frequency of good and poor clinical outcomes in a well-established RITH service in Western Australia, suggesting pattern recognition of an at-risk cohort by identifying potentially useful predictors of poor outcome. WHAT ARE THE IMPLICATIONS FOR PRACTITIONERS?: RITH services are a safe alternative for many, including older people. Health administration databases are useful tools to monitor clinical outcomes. Clinical indicators such as older age, long hospital stay and orthopaedic diagnoses may be useful predictors of poor outcomes in such services.

Central auditory maturation and babbling development in infants with cochlear implants.

OBJECTIVE: To examine the relationship between the maturation of central auditory pathways and the development of canonical (speechlike) babbling in infants with cochlear implants. DESIGN: Comparison of the latencies of the P1 cortical auditory evoked potential and vocalizations produced by subjects before they were fitted with a cochlear implant and at several time points within the first year after implantation. SUBJECTS: Two congenitally deaf children who were implanted with a multichannel cochlear implant at ages 13 and 14 months. INTERVENTIONS: P1 response latencies were recorded in response to a /ba/ stimulus before implantation and at several time points following implantation. Vocalizations produced by the subjects while interacting with their caregiver were audiorecorded twice before implantation and at monthly sessions following implantation. RESULTS: Subjects showed a rapid decrease in P1 latencies resulting in normal P1 latencies within about 3 months after implantation. Before implantation, the vocalizations were primarily of a precanonical nature. After 3 months' experience with the implants, the proportion of canonical vocalizations increased dramatically relative to the number of precanonical utterances. CONCLUSIONS: Results of this study suggest that the development of P1 response latencies and the development of early communicative behaviors may follow a similar developmental trajectory in children implanted early. Although preliminary, these findings indicate that the development of early communicative behaviors following implantation may be positively influenced by the rate of plastic changes in central auditory pathways.