ABSTRACT
Primary molar teeth that are retained beyond their exfoliation pose a clinical decision-making challenge for dental teams. The retention of these teeth may be due to absence of a permanent successor. As a result, careful planning is required to determine if retention or extraction is necessary. This article aims to discuss the prevalence of retained primary molars, assessment and treatment planning considerations, from both orthodontic and restorative perspectives.
Subject(s)
Anodontia , Humans , Anodontia/diagnostic imaging , Anodontia/therapy , Molar , Tooth, Deciduous , Dentistry , Clinical Decision-MakingABSTRACT
Dentin dysplasia(DD) is a rare autosomal dominant disorder associated with disturbance of the dentin. While the crowns appear clinically normal, on radiography, the pulp spaces appear partially or completely obliterated, with short blunted roots, and multiple periapical radiolucencies affecting the apparently sound teeth. Clinical signs include spontaneous abscess formation or increased tooth mobility which can lead to exfoliation. DD can therefore have a significant impact on the patient's dentition, and treatment is often challenging. Shields' classification of dentin disorders has been recently criticised for failing to consider differential variations and expressions of these disorders. This paper describes a case of a 23-year-old woman with previously undiagnosed DD, who presented with clinical and histological features belonging to several of these diseases, thus highlighting the potential diagnostic challenges faced with Shields' classification.
Subject(s)
Dentin Dysplasia/diagnosis , Tooth Root/abnormalities , Cone-Beam Computed Tomography , Dentin Dysplasia/classification , Dentin Dysplasia/pathology , Dentin Dysplasia/surgery , Female , Humans , Oral Hygiene , Radiography, Panoramic , Tooth Extraction , Tooth Root/diagnostic imaging , Young AdultABSTRACT
Four groups of specimens were constructed using bovine enamel and composite resin. After a period of ageing, the specimens were roughened and acid etched before they were cemented to air abraded base metal alloy beams with a universal resin cement. After further ageing, tensile peel testing was carried out using a Universal Testing Machine. The force required to produce failure increased as the amount of composite resin on the bonding surface of the abutment increased. This difference reached statistical significance (p < 0.5) when the abutments contained > 50% composite. The mode of failure was mixed on the majority of retainers. Within the limitations of the study, findings suggest that RBB retainers can be cemented to abutments restored with composite resin without a reduction in bond strength.
Subject(s)
Composite Resins/chemistry , Dental Abutments , Dental Bonding , Dental Enamel/ultrastructure , Dental Materials/chemistry , Denture Retention/instrumentation , Denture, Partial, Fixed, Resin-Bonded , Acid Etching, Dental/methods , Animals , Cattle , Cementation/methods , Chromium Alloys/chemistry , Dental Etching/methods , Dental Restoration Failure , Dental Stress Analysis/instrumentation , Materials Testing , Resin Cements/chemistry , Stress, Mechanical , Surface Properties , Temperature , Tensile Strength , Time Factors , Water/chemistryABSTRACT
AIMS: The purpose of the present study was to measure the intrapulpal temperature rise occurring during polymerisation of different shades of resin-based composites (RBCs), and two light-emitting diode (LED) units. METHODS: Seventy non-carious permanent molars, that had been extracted for orthodontic purposes and stored in 2% thymol for not more than four months, were selected. Patient age range was 11-18 years. Standard cavity preparation with standardised remaining dentine thickness and placement of thermocouples (TCs) was prepared using a novel split-tooth technique. Cavities were filled with one of two shades of RBC (A2 and C4, Filtek Z250, 3M ESPE, Seefeld, Germany), and cured with two LED high-intensity units (Elipar Freelight2, 3M ESPE, Seefeld, Germany; Bluephase, Ivoclar Vivadent, Schaan, Liechtenstein) and a conventional halogen light-curing unit (LCU) (Prismetics Lite 2, Dentsply, Weybridge, Surrey, UK) as a control. RESULTS: Pulp temperature rises during bonding [A2 results: H;2.67/0.48:E;5.24/1.32;B;5.99/1.61] were always greater than during RBC curing [A2 results: 2.44/0.63;E3.34/0.70;B3.38/0.60], and these were significant for both LED lights but not for the halogen control, irrespective of shade (Mann-Whitney test: 95% confidence limits). Temperature rises were at times in excess of the values normally quoted as causing irreversible pulp damage. Pulp temperature rises during bonding were higher with the LED lights than with the halogen control. There was no significant difference in temperature rise between the two LED lights when bonding but there was a significant difference between the two LED lights and the halogen control LCUs (Kruskal-Wallis Test: 95% confidence limits). CONCLUSIONS: The results support the view that there is a potential risk for heat-induced pulpal injury when light-curing RBCs. The risk is greater during bonding and with high energy, as compared to low-energy output systems. As the extent of tolerable thermal trauma by the pulp tissues is unknown, care and consideration should be given to the choice of LCU and the exposure time when curing RBCs, and especially during bonding.
