Heat generated during dental treatments affecting intrapulpal temperature: a review.

INTRODUCTION: Heat is generated and transferred to the dentine-pulp complex during various dental procedures, such as from friction during cavity preparations, exothermic reactions during the polymerisation of restorative materials and when polishing restorations. For in vitro studies, detrimental effects are possible when intra-pulpal temperature increases by more than 5.5°C (that is, the intra-pulpal temperature exceeds 42.4°C). This excessive heat transfer results in inflammation and necrosis of the pulp. Despite numerous studies stating the importance of heat transfer and control during dental procedures, there are limited studies that have quantified the significance. Past studies incorporated an experimental setup where a thermocouple is placed inside the pulp of an extracted human tooth and connected to an electronic digital thermometer. METHODS: This review identified the opportunity for future research and develop both the understanding of various influencing factors on heat generation and the different sensor systems to measure the intrapulpal temperature. CONCLUSION: Various steps of dental restorative procedures have the potential to generate considerable amounts of heat which can permanently damage the pulp, leading to pulp necrosis, discoloration of the tooth and eventually tooth loss. Thus, measures should be undertaken to limit pulp irritation and injury during procedures. This review highlighted the gap for future research and a need for an experimental setup which can simulate pulp blood flow, temperature, intraoral temperature and intraoral humidity to accurately simulate the intraoral conditions and record temperature changes during various dental procedures.

Atypical clinical presentation of distal renal tubular acidosis: a case report registered in Amazonas, Brazil / Apresentação clínica atípica da acidose tubular renal distal: relato de caso registrado no Amazonas, Brasil

ABSTRACT We report an unusual case of a 24-year-old girl with a history of recurrent hypokalemic paralysis episodes and skin lesions on the lower limbs and buttocks, both of which had an acute evolution. In subsequent investigations, the patient also had nephrocalcinosis, nephrolithiasis, hyperchloremic metabolic acidosis and persistent alkaline urinary pH. The findings were consistent with distal renal tubular acidosis as the cause of hypokalemic paralysis. Clinical findings, immunological tests and the result of skin biopsy suggested primary Sjögren's syndrome as an underlying cause. The patient developed azotemia due to obstructive nephrolithiasis. All the features presented in this case are an unusual manifestation of distal renal tubular acidosis; so far, we are not aware of a similar report in the literature.

RESUMO Relatamos um caso incomum de uma jovem de 24 anos com história de episódios recorrentes de paralisia hipocalêmica e lesões cutâneas em membros inferiores e nádegas, ambas de evolução aguda. Em investigações subsequentes, verificou-se que a paciente apresentava nefrocalcinose, nefrolitíase, acidose metabólica hiperclorêmica e pH urinário persistentemente alcalino. Os achados foram consistentes com acidose tubular renal distal como causa da paralisia hipocalêmica. Achados clínicos, exames imunológicos e o resultado da biópsia de pele foram compatíveis com a síndrome de Sjögren primária como causa subjacente. A paciente evoluiu com azotemia em decorrência da nefrolitíase obstrutiva. Todas as características apresentadas nesse caso são uma manifestação incomum de acidose tubular renal distal; até o momento, não temos conhecimento de um relato semelhante na literatura.

Atypical clinical presentation of distal renal tubular acidosis: a case report registered in Amazonas, Brazil.

We report an unusual case of a 24-year-old girl with a history of recurrent hypokalemic paralysis episodes and skin lesions on the lower limbs and buttocks, both of which had an acute evolution. In subsequent investigations, the patient also had nephrocalcinosis, nephrolithiasis, hyperchloremic metabolic acidosis and persistent alkaline urinary pH. The findings were consistent with distal renal tubular acidosis as the cause of hypokalemic paralysis. Clinical findings, immunological tests and the result of skin biopsy suggested primary Sjögren's syndrome as an underlying cause. The patient developed azotemia due to obstructive nephrolithiasis. All the features presented in this case are an unusual manifestation of distal renal tubular acidosis; so far, we are not aware of a similar report in the literature.

Real-time pulp temperature change at different tooth sites during fabrication of temporary resin crowns.

AIM: To record the pulp temperature at different tooth sites during fabrication of two different temporary crown systems. METHODOLOGY: Two temporary crown systems were investigated; a conventional direct fabricated and a preformed thermoplastic resin system. Extracted caries-free human teeth (incisor, premolar and molar) were prepared for full coverage ceramic restoration with roots sectioned below the cemento-enamel junction. Thermocouple wires were secured at the surface of crown material, the cut dentine and inside the pulp cavity. Provisional crowns (n = 10/group) from each system were formed prior to placement in a water bath of 37 °C to simulate pulpal temperature. Temperatures were recorded using a K-type thermocouple data logger to collect the mean and peak temperature during crown fabrication. Statistical analysis was carried out on all tested groups and heat flow was calculated. RESULTS: For direct fabricated crowns, the mean rise in pulpal temperature recorded was 0.1 °C with the mean temperature range of 37.3 °C-37.8 °C. For the preformed thermoplastic crowns, the mean rise in pulpal temperature recorded was 37.3 °C-45.1 °C. The increase in temperature was significantly higher (6.5 °C for the incisor group, 7.5 °C for the premolar group, and 6.7 °C for the molar group). For both crown systems, the temperature difference between the three different sites; pulp, crown and tooth surface showed a statistical difference (P < 0.01). CONCLUSIONS: The direct fabrication system showed minimal temperature changes within the teeth, while the preformed thermoplastic fabrication system showed larger temperature change in the teeth.