Biomedical subjects
F J Burke
Publications and source records attributed to F J Burke.
Improving and monitoring autoclave performance in dental practice.
The sterilisation of instruments is central to the infection control process in the dental surgery, with the autoclave being most frequently used for this process. For effective operation, among other factors, it is essential that the autoclave is loaded correctly and tested regularly to ensure that it is operating at a temperature and pressure which will kill all micro-organisms. Biological indicators are another method of verifying the sterilisation process, since the sterilisation of the bacterial spores within the test ampoule provides a guarantee that sterilising conditions have been achieved.
Incisal edge reattachment: indications for use and clinical technique.
This article presents an overview of the evolution of the incisal edge reattachment procedure. Case reports are described of patients presenting with traumatised teeth in which the reattachment procedure was performed. A review is provided of present in vivo studies detailing long-term success rates in the clinical application of this procedure. Finally, a recommended technique for diagnosis and treatment is offered to improve success in this procedure which may benefit a significant segment of the paediatric and adolescent populations.
The aetiology of the non-carious cervical lesion.
Erosion and abrasion have been widely reported as causes of non-carious cervical lesions (NCCL). However, more recently, tooth flexure has been implicated in the formation of these lesions generating renewed interest in the pathogenesis of the non-carious loss of cervical tooth substance. This paper considers the causes of erosion and abrasion, related to modern lifestyles, and reviews the literature concerning tooth flexure as a cause of NCCL. A description of different types of NCCL is given, as an aid to determining the aetiology, yet at the same time accepting that the causation and pathogenesis of NCCL is probably multi-factorial resulting in many different clinical presentations. Consideration is given to the indications for treatment of NCCL and to the selection of materials for restoring such defects.
Fracture resistance of teeth restored with onlays of three contemporary tooth-colored resin-bonded restorative materials.
STATEMENT OF PROBLEM: There are uncertainties regarding the use of large indirect composites and ceramics in the restoration of posterior teeth. PURPOSE: This study investigated the fracture resistance of teeth restored with restorations of 3 contemporary resin-bonded tooth-colored materials placed in a standardized onlay preparation. MATERIAL AND METHODS: A random sample of preparations for tooth-colored onlays was obtained from a full service dental laboratory. A preparation was then duplicated in 30 natural teeth by copy milling. An additional 10 teeth were not prepared, and acted as a control. Ten onlays of each of the 3 materials (Belle Glass, SR Isosit, and Empress) were produced and resin bonded into place according to the manufacturers' instructions. The restorations were compressively loaded to fracture and the mode of failure recorded. RESULTS: The fracture resistances obtained for the teeth restored with the composite material (mean 1.56 kN; SD 0.54) were greater than those obtained for the teeth restored with the ceramic material (mean 0.99 kN; SD 0.49) and the fiber-reinforced composite material (mean 0.99 kN; SD 0.56). CONCLUSION: Teeth restored with composite onlay restorations demonstrated a higher fracture resistance than equivalent sized onlay restorations produced from fiber-reinforced composite or a ceramic material. Failure under compressive loading may be found to be less catastrophic when a fiber-reinforced composite rather than a composite or ceramic material is used.
Fracture resistance of teeth restored with dentin-bonded crowns constructed in a leucite-reinforced ceramic.
OBJECTIVES: Laboratory studies and preliminary clinical data have demonstrated satisfactory fracture resistance of all-ceramic crowns placed using a resin-composite luting material and a dentin-bonding system. This study investigates the fracture resistance of crowns constructed in a leucite-reinforced ceramic when placed using a dentin-bonding system and a dual-cure resin composite luting material and compares this with the fracture resistance of feldspathic porcelain crowns. METHOD: Standardised preparations were carried out on 10 sound, unrestored, maxillary premolar teeth, the mean bucco-palatal width of which did not vary by more than 2.5%. Ceramic crowns (Fortress; Chameleon Dental, KS, US) were constructed using a standardised technique. Their fitting surface was etched with hydrofluoric acid. The crowns were placed using the dentin-bonding system Mirage ABC and the luting system Mirage FLC (Chameleon Dental, KS, US). The restored teeth were loaded in compression at 1 mm/min through a 4 mm steel bar placed along the midline fissure. RESULTS: A mean fracture load of 0.88 kN was recorded. Results from previous work indicate a fracture resistance of 0.77 kN for feldspathic porcelain crowns placed using the same luting systems on similarly standardised preparations. Statistical analysis by one-way ANOVA and Tukey's multiple comparison procedure indicated that there was no significant difference in the mean fracture resistance of the teeth restored using the leucite reinforced ceramic and the teeth restored with feldspathic porcelain. SIGNIFICANCE: Crowns constructed in a leucite-reinforced ceramic and placed using dentin-bonding and dual-cure resin composite luting materials may provide some increase in fracture resistance, but the results may not be significantly different from the feldspathic porcelain.
Maximising the fracture resistance of dentine-bonded all-ceramic crowns.
Results of previous studies have indicated that the use of different ceramic materials and differing bonding/luting systems may affect resistance to fracture of teeth restored with dentine-bonded crowns. It is the purpose of this investigation to examine in vitro fracture resistance of dentine-bonded ceramic crowns, using materials in combination which have demonstrated increased fracture resistance when they are used individually. Ten sound maxillary premolar teeth were selected. These teeth were prepared for full crowns in a similar manner to previous, related studies. Standardised crowns were constructed in a leucite reinforced ceramic (Empress: Ivoclar-Vivadent, Liechten-stein) and placed using a dentine-bonding system and resin-composite luting system (3M; St. Paul, MN, USA). Compressive force was applied through a 4 mm diameter steel bar applied to the occlusal surface of the restored specimens. A mean fracturing force of 1.67 kN was recorded, statistical analysis indicating that this was significantly greater than any previously used combination of ceramic material and bonding/luting system, and greater than a group of sound, unrestored teeth. The fracture resistance of teeth restored in vitro by dentine bonded crowns may be enhanced by the combination of the materials described.
Variation in periodontal referral in 2 regions in the UK.
This study investigated the periodontal referral patterns of general dental practitioners (GDPs) in Northern Ireland (NI) and North West England (NWE). A questionnaire dealing with periodontal referral was sent to all 520 GDPs registered in NI and to 274 GDPs in NWE. A usable return was made by 355 (68%) in NI and 189 (70%) in NWE. The NI dentists made significantly more periodontal referrals (median 5, range 0-80) in the year preceding the survey than those in NWE (median 2, range 0-50), p<0.001. Distance was the only factor significantly related to the referral rate in both regions with those who practised more than 25 miles from a specialist referring significantly fewer patients in both regions. In NI, there was a trend towards increased periodontal referral by GDPs who had attended more postgraduate courses; however, in NWE, this was not the case. The GDPs in NWE were significantly less likely than those in NI to refer patients with medical conditions. It is concluded that there is considerable variation in periodontal referral both within and between the 2 regions studied. It is further concluded that in many cases, non-disease factors, such as the accessibility of the specialist service, have powerful effects on the decisions made by dentists and patients in these regions (NI and NWE) in relation to periodontal referral. Much of the variance in referral in North West England, as in Northern Ireland, remains unexplained.
Reconstruction of a hemisectioned tooth with an adhesive ceramic restoration using intraradicular retention.
Hemisection may be a valuable form of treatment for molar teeth when one root is considered unrestorable. However, following hemisection the clinician may encounter difficulty in restoring the remaining tooth fragment, which may not possess adequate bulk for the placement of a post. This case report describes an adhesive technique in which a ceramic crown is bonded intraradicularly to the hemisectioned root.
Predisposing and contributing factors for complete and incomplete tooth fractures.
The rehabilitation of fractured teeth may create problems for both patient and clinician. This paper updates the reader on the many factors that have been implicated in the aetiology of fractures, so highlighting a preventive rather than curative perspective to clinical dentistry.
Restoration longevity and analysis of reasons for the placement and replacement of restorations provided by vocational dental practitioners and their trainers in the United Kingdom.
OBJECTIVE: This study examined the reasons given by vocational dental practitioners and their trainers for placement and replacement of restorations. METHOD AND MATERIALS: Each participant was asked to record the reason for placement or replacement of restorations. The age and class of the restoration being replaced were also recorded, as was the material being used and the material being replaced (if known). RESULTS: Details of the reason for placement or replacement was received on 9,031 restorations. Of the restorations placed, 53.9% were amalgam, 29.8% were resin composite, and 16.3% were glass-ionomer cement. The reasons for placement or replacement of the restorations were principally primary caries (41.3%), secondary caries (21.9%), tooth fracture (6.4%), marginal fracture or degradation (6.1%), and noncarious defects (5.8%). Of the amalgam restorations, most were placed to restore Class II and Class I preparations (65.8% and 29.9%, respectively). Of the composite restorations, most were placed in Class III and Class V cavities (35.5% and 26.3%, respectively). Glass-ionomer cement was used predominantly to restore Class V cavities (63.5%). CONCLUSION: Secondary caries was the most prevalent reason for replacement of restorations, regardless of material. Statistical analysis indicated that amalgam provided significantly greater longevity than composite or glass-ionomer materials.
Reasons for the placement and replacement of restorations in vocational training practices.
AIM: The reasons for placement and replacement of restorations are central to clinical practice. It is the purpose of this paper to assess the reasons for placement and replacement of restorations in the practices of vocational dental practitioners (VDPs) and their trainers. METHOD: VDPs and their trainers were invited to take part in the study. VDPs were asked to record the principal reason for the placement or replacement of all restorations which they provided for a one-month period and, also, to record the age, Class and materials used for each restoration replaced (if known). Trainers were also asked to participate. The data thereby collected were analysed statistically. RESULTS: 56 VDPs and 17 trainers participated. Data were obtained on a total of 9031 restorations, 4423 (49%) being initial placements and 4608 (51%) replacements. Of the total number of restorations assessed, 54% were amalgam, 30% composite and 16% glass ionomer. Principal reasons for placement/replacement of the restorations were primary caries (41%), secondary caries (22%), tooth fracture (6%), margin fracture/degradation (6%), non-carious defects (6%) and bulk fracture (5%). The type of existing restorative material was recorded for 4196 restorations: secondary caries was the most common reason for the replacement of restorations--for 46.0%, 39.6% and 39.8% of amalgam, composite and glass-ionomer restorations respectively. VDPs placed more restorations as a consequence of caries than their trainers. CONCLUSION: Primary caries is the most common reason for the placement of restorations by the participating dentists, and secondary caries is the most common reason for the replacement of restorations of amalgam, composite and glass ionomer. VDPs placed more restorations as a consequence of caries than their trainers.
Appropriate and inappropriate referrals to a unit of conservative dentistry.
Inappropriate referrals to secondary care are an unnecessary cost, notwithstanding the effect on waiting lists. It is essential therefore that only those patients whose referrals are appropriate are actually referred for secondary care. This project aimed to determine whether referrals to a unit of conservative dentistry are appropriate. The records of 120 consecutive new patient referrals who had been examined by one consultant in the unit of conservative dentistry at Glasgow Dental Hospital and School were obtained. A pro forma was designed on which synopses of the relevant clinical findings were written. These synopses were examined by four general dental practitioners (GDPs). A referral was considered appropriate if three or four of the GDPs considered it to be so, a referral was considered inappropriate if three or four of the GDPs concurred. Of the 120 cases examined, a majority of the GDP assessors agreed that 54 warranted referral, with 23 of these being referrals for toothwear. Agreement was not reached in 35 cases, while 31 referrals were considered inappropriate. Of the 31 cases which were considered inappropriate, 27 were thought to be within the scope of general practitioners. In conclusion, the results suggest that around one quarter of referrals to a unit of conservative dentistry are inappropriate. It would appear that a number of GDPs are unable or unwilling to treat a variety of simple conditions in practice and it may be that the development of referral guidelines is necessary to ensure that only those patients who merit a specialist opinion are referred for this service.
Patient attitudes to glove use by dentists.
OBJECTIVE: To evaluate the attitudes of patients on the importance of glove wearing by dentists. DESIGN: A patient survey using a self-completed patient questionnaire. SETTING: Ireland. SUBJECTS AND METHODS: 164 consecutive patients attending a dental accident and emergency department were asked to participate. All the patients were aged 16 years or over. Of the surveyed patients, 157 completed a questionnaire designed to elucidate the patients' attitudes to the wearing of gloves by dentists. RESULTS: Most patients (93.6%; n = 147) considered that dentists should routinely wear gloves, while 1.9% (n = 3) thought the wearing of gloves was unnecessary. 94.9% (n = 149) considered that gloves were worn to protect both the dentist and the patient, with 1.9% (n = 3) feeling that only the dentist was protected. 72% of patients (n = 113) would not attend a dentist who did not wear gloves. 87.2% (n = 138) of patients thought that the dentist should change gloves between patients, while 1.3% (n = 2) considered glove washing to be sufficient. The remaining 11.4% (n = 17) felt that this decision should be left to the dentist. CONCLUSION: The majority of surveyed individuals indicated that dentists should wear gloves while treating patients. The results suggest that many patients refuse to have dental treatment carried out by a dentist who does not wear gloves.