What are the indications for three-dimensional X-ray-diagnostics and image-based computerised navigation aids in dental implantology?

Purpose: The objective of this systematic review as a basis for an expert consensus was to answer the following question: What are the indications for three-dimensional (3D) X-ray-diagnostics and image-based computerised navigation aids in dental implantology? Materials and methods: Independent professionals performed a systematic literature search up to 30 June 2010, looking upon existing national and international guidelines, consensus papers of scientific societies and the literature database of the Cochrane Library and MEDLINE. As there were only a few randomised controlled trials (RCTs) and other systematic, clinical studies on this subject, the research was supplemented by results from basic research and animal studies and related topics. Additional literature was included on the basis of recommendations by experts involved in the consensus process. The paper was given consent at the DGI Consensus Conference in a structured consensus process guided by an independent moderator of the AWMF (Association of the Scientific Medical Societies in Germany). This led to the following clinical recommendations. Results and conclusions: Part 1: No randomised or controlled studies on humans confirmed the superiority of 3D imaging regarding the quality of the surgical result and or the incidences of complications in implantology. The clinician should be aware of the additional increased radiation exposure compared to 2D images, especially critical in young individuals. Possibilities of reducing the field of view and therefore the radiation exposure should be utilised. The ALARA principle (as low as reasonably achievable) should be followed. Indications for 3D imaging were formulated. Part 2: The application of navigation-supported implantology requires surgical experience in the field of non-navigation-based implantology. The surgeon should always be capable of switching to conventional surgery in a clinical case. Indications for computerised navigation aids were formulated.     

How effective is ART in the management of dental caries?

The ART approach involves excavating cavitated dentine caries with hand instruments, then restoring the cavity and sealing any associated fissures and pits with an adhesive restorative material, resulting in a sealant restoration. Until recently, ART has mainly been used under field conditions, and thus the adhesive restorative material used has been glass ionomer which does not require mixing machines and curing lights. Since the inception of ART, a growing number of studies world-wide have taken place. A total of four studies have reported 3-year survival percentages for one-surface ART restorations. The highest 3-year survival percentage in permanent teeth was 88%, which is comparable to the 85% survival of one-surface amalgam restorations placed under the same field conditions after 3 years. The outcomes depend to some extent on the material used, operator experience and presence of caries. The presence of caries as a reason for failure was higher in the early than in the most recent studies. Only one study has reported on the use of ART restorations in the deciduous dentition. It is concluded that: a very large proportion of dentine lesions in the permanent teeth can be treated using the ART approach; the 3-year survival rate of the more recently placed one-surface ART restorations in permanent teeth was higher than that of ART restorations placed in the beginning; the survival of one-surface ART restorations in the permanent dentition with newer glass ionomers is comparable to that of one-surface conventional restorations placed using amalgam in a comparable setting after 3 years; more studies of longer duration are needed to confirm these findings; ART should be considered a caries treatment modality that benefits people; and educational courses need to be organised before the approach is applied in the clinic.     

Impact of oral fluids on dental ceramics: What is the clinical relevance?

Objectives

In this brief and selective overview, basic factors contributing to aqueous induced dissolution, phase changes of zirconia and mechanical strength degradation of dental ceramics are considered.

Methods

Dissolution is important for porcelain and glass-ceramic materials as they predominantly contain a silica glass structure with various other cations incorporated which disrupt the silica network. In glass-ceramic materials and porcelains containing crystalline components the situation is more complex as the difference in the dissolution rate may increase the surface roughness and contribute to abrasion of the opposing definition.

Results

Factors contributing to the aqueous dissolution of silicate based dental ceramics and induced destabilization of Y-TZP zirconia or low temperature degradation (LTD) are considered. It is also noted that there have been a number of reports of spontaneous fracture of 3Y-TZP specimens because of LTD in the absence of external stress. A simple analysis of this situation is presented which indicates a strong specimen-size effect and also implicates the role of the remnant “pseudo-grain” structure resulting from the pressing of spray-dried powder agglomerates.

Significance

The final section of this review addresses the consequences of various environments on crack growth and strength degradation. In some situations it is suggested that the aqueous environment may enhance the strength of restorative materials. In all instances discussed above the clinical consequences are pointed out.     

How is the biocompatibilty of dental biomaterials evaluated?

All biomaterials used in dentistry must be evaluated for biocompatibility using screening assays to protect patient health and safety. The purpose of this review is to explain the international biocompatibility guidelines, and to explain the structure of a test program. The test program requires the structured assessment of materials into four phases; general toxicity, local tissue irritation, pre-clinical, and clinical evaluation. Different types of screening assays are available, and it is important to understand the advantages and limitations of the various types of assays that are available, so that they can be selected for appropriateness and interpreted accurately. New scientific advances in terms of the chemical properties of dental materials, tissue engineering, stem cell, genetic transfer, biomaterial, and growth factor therapies are under development. These new therapies create improved opportunities to restore and regenerate oral tissues, but they can also present new hazards to patients. Prior to their clinical use, these new technologies must be proven to be safe, and not hazardous to human health. A structured biocompatibility assessment and advice on the selection of assays are outlined to evaluate these new therapies.     

Does osteoporosis increase marginal bone loss around dental implants in the posterior of the maxilla?

Osteoporosis is caused by an imbalance in bone remodelling. The aim of this study was to compare the marginal bone loss (MBL) around dental implants placed in the posterior maxilla between osteoporotic and non-osteoporotic female patients. This was a prospective cohort study. Female patients needing a dental implant restoration in the posterior maxilla were included. Dual-energy X-ray absorptiometry was performed and the T-score recorded. MBL was measured at 12 months after loading. The patients were assigned to one of two groups: group 1, osteoporotic (T-score ≥2.5); group 2, non-osteoporotic (T-score <2.5). In this study, osteoporosis was the primary predictor variable and MBL was the outcome variable. The mean MBL was compared between the two groups using an independent t-test. Pearson’s correlation test was applied to identify any correlation between the T-score and MBL. Ninety female patients were studied, 44 in group 1 and 46 in group 2. The mean MBL was 1.20 ± 0.29 mm in group 1 and 0.87 ± 0.15 in group 2; this difference in mean MBL was statistically significant (P = 0.001). There was a correlation between T-score and MBL (P = 0.001). Despite the correlation between T-score and MBL, this study did not provide enough evidence to prove any causal relationship between MBL and osteoporosis.     

Why is there heterogeneity in the effect of dental checkups? Assessing cohort effect

Celeste RK, Nadanovsky P. Why is there heterogeneity in the effect of dental checkups? Assessing cohort effect. Community Dent Oral Epidemiol 2010; 38: 191–196. © 2010 John Wiley & Sons A/S Abstract – Objectives: To evaluate age as a potential effect modifier of the relation between frequency of dental check‐up and oral health. Methods: Data from a Brazilian oral health survey carried out in 2002–2003 was obtained for three age groups: 15–19‐year‐old (n = 16411); 35–44‐year‐old (n = 13 269); and 65–74‐year‐old (n = 5 300). Individuals were examined by dentists and followed to an interview. Self‐reported time since last dental visit was measured as ‘less than 1 year’; ‘from 1 to 2 years’; ‘3 or more years’ or ‘never’. Outcomes modelled with negative binomial regression were DMFT index and DT, MT and FT. Results: Visiting the dentist more recently was associated with fewer teeth with untreated dental caries (DT) and more teeth with fillings (FT) across all age groups. Among the 15–19‐year‐old, the longer the time since last visit the lower the DMFT and MT. On the other hand, among the 35–44 and the 65–74‐year‐old the longer the time since last dental visit the higher the DMFT and MT, though this trend reverted in the ‘never visited’ group. Conclusions: Age modified the effect of dental visits on DMFT and MT. In younger cohorts, the low frequency of dental check‐up among those with good oral health may reflect the fact that these young people do not feel they need to go to the dentist very often, while in older cohorts, the current low frequency of dental check‐up associated with bad oral health may be a reflection of a lifetime of high disease incidence coupled with access barriers. Questions regarding the time and frequency of dental visits may capture different dimensions of utilization of dental services, and so pooled estimates are not appropriate. Our results may help explaining contrasting results in previously published studies.     

Magnetic resonance imaging for three-dimensional printing of the bony orbit: is clinical use imminent?

The aim of this study was to examine the accuracy of three dimensionally (3D) printed models of the bony orbit derived from magnetic resonance imaging (MRI) for the purpose of preoperative plate bending in the setting of orbital blowout fracture. Retrospective computed tomography (CT) and MRI data from patients with suspected orbital fractures were used. Virtual models were manually generated and analysed for spatial accuracy of the fracture margins. 3D-printed models were produced and orbital fan plates bent by a single operator. The plates were then digitized and analysed for spatial discrepancy using reverse engineering software. Seven orbital blowout fractures were evident in six orbits. Analysis of the virtual models revealed high congruence between blowout fracture margins on CT and MRI (n = 7, average deviation 0.85 mm). Three zygomaticomaxillary complex fractures were seen, for which MRI did not demonstrate the same accuracy. For plates bent to the 3D-printed models of blowout fractures (n = 6), no significant difference was found between those bent to CT versus those bent to MRI when compared for average surface and average border deviation (Wilcoxon signed rank test). Orbital blowout fractures can be defined on MRI with clinically acceptable accuracy. 3D printing of orbital biomodels from MRI for bending reconstructive plates is an acceptable and accurate technique.     

Bicycle helmets--does the dental profession have a role in promoting their use?

OBJECTIVES: To review the available literature regarding the: epidemiology of bicycle related head injuries; consequences of head injuries; rates of cycle helmet use; impact of educational campaigns and legislation on usage rates; effectiveness of cycle helmets in protecting against head and facial injuries; arguments against the compulsory use of bicycle helmets. DATA SOURCES: A computerised Medline search was conducted using the keywords: head injury, facial injury, bicycle helmets, accidents. DATA SELECTION: All available information was considered. DATA SYNTHESIS: Data was collated manually. CONCLUSIONS: The wearing of bicycle helmets contributes significantly to the prevention of head injuries (HI) and traumatic brain injury (TBI), particularly in children and adolescents.There is evidence to support the role of cycle helmets in the prevention of injuries to the middle third of the face and some dental injuries. There is a case for the implementation of legislation accompanied by educational campaigns to increase significantly the use of cycle helmets.The dental profession could: play an active role in promoting cycle helmet use; support calls for the compulsory wearing of cycling helmets, particularly for children; press for modification of helmet design and standards to increase protection of the face.     

Blood pressure measuring equipment in the dental surgery: use or ornament?

OBJECTIVE: To survey the attitudes, knowledge and practice of general dental practitioners (GDPs) with regard to hypertension in dental patients and to assess opinion with regard to the concept of screening. SETTING: General dental practice. SUBJECTS AND METHODS: GDPs via a postal survey. To achieve an acceptable level of accuracy, at least 196 responses were required. RESULTS: Out of 300 questionnaires, 207 were returned (69% response rate). Most practitioners (98%) had received training in the measurement of blood pressure. Only 4.8% measured blood pressure routinely and this figure rose to 9.2% in patients with a known history of hypertension. Only 27.1% felt that the involvement of dentists in screening for hypertension was a good idea but 85.3% thought that education of practitioners about hypertension would be valuable. CONCLUSION: Most GDPs thought that education of practitioners about hypertension was a good idea. They did not, however, want to be involved with screening of patients for hypertension.     

Gender differences in dental anxiety: is the chair position important?

Dental anxiety in the general population is more prevalent in females than in males. The presence of dental anxiety was studied in a group of 189 females and 176 males using the following scales: the Dental Anxiety Scale (divided into DAS 1 containing 6 items, which explores a patient's dental anxiety and DAS 2 containing 13 items, which looks at dental anxiety concerning dentist-patient relations), the Self-Rating Depression Scale (SDS), and the Quality of Life Index (QL-Index). The results obtained showed significant differences only in relation to dental anxiety regarding the use of instruments (such as needles and handpieces) and the tilted-back position of the chair (DAS 1). No significant gender differences emerged between the two groups in relation to dental anxiety regarding dentist-patient relations (DAS 2), depression (SDS), and the quality of life (QL-Index). The results may explain why women avoid dental care and indicate new designs to make the chair position more comfortable would be useful.     

Income or education,which has a stronger association with dental implant use in elderly people in Japan?

Objectives: Although inequalities in dental implant use based on educational level have been reported, no study has used income as a proxy for the socioeconomic status. We examined: (i) income inequalities in implant use; and (ii) whether income or education has a stronger association with implant use in elder Japanese. Methods: In 2016, a self-reported questionnaire was mailed to participants aged 65 years or older living across Japan as part of the ongoing Japan Gerontological Evaluation Study. We used data from 84,718 respondents having 19 or fewer teeth. After multiple imputation, multi-level logistic regression estimated the association of dental implant use with equivalised income level and years of formal education. Confounders were age, sex, and density of dental clinics in the residential area. Results: 3.1% of respondents had dental implants. Percentages of dental implant use among the lowest (≤ 9 years) and highest (≥ 13 years) educational groups were 1.8 and 5.1, respectively, and among the lowest (0 < 12.2 ‘1,000 USD/year’) and highest (≥ 59.4 ‘1,000 USD/year’) income groups were 1.7 and 10.4, respectively. A fully adjusted model revealed that both income and education were independently associated with dental implant use. Odds ratios for implant use in the highest education and income groups were 2.13 [95% CI = 1.94–2.35] and 4.85 [95% CI = 3.78–6.22] compared with the lowest education and income groups, respectively. From a model with standardised variables, income showed slightly stronger association than education. Conclusion: This study reveals a public health problem that even those with the highest education but low income might have limited accessibility to dental implant services.Key words: Dental implant(s), access to care, dental services research, dental public health, epidemiology