Evaluation of the efficacy of a prosthodontic stent in determining the position of dental implants

Purpose: To evaluate the efficacy of a dual purpose (diagnostic and surgical) acrylic resin stent with gutta percha marker used in conjunction with 3D imaging in determination of the position and inclination of dental implants. Materials and Methods: This study was performed as a case control study. A total of 41 implants, of which 20 had been placed without the use of stents and 3D imaging (control group) and 21 were placed using stents and 3D imaging (study group), were studied. A diagnostic and surgical stent with radio‐opaque indicator (gutta percha) was fabricated to determine the planned prosthetic position and inclination of the implant. Computed tomography images were obtained and were analyzed using Denta Scan software. The position of the implant was analyzed in mesiodistal and buccolingual dimensions in terms of both position and angulation. SPSS v15.0 was used for statistical analysis (p < 0.05 was considered statistically significant). Results: The study group demonstrated an overall 98.9% efficacy of the test technique being used in the study. On qualitative assessment, the results obtained were within the defined ideal threshold level for four of five parameters (distance from buccal and lingual cortical plate, inter‐implant distance, and buccolingual angulation of the implant relative to underlying alveolar bone). For mesiodistal distance from adjacent teeth, the observation was not above threshold value for only one case. For the control group, the overall efficacy was 66.9%. Conclusion: The technique of combined use of a prosthodontic stent and 3D imaging is an efficacious and better technique in achieving an ideal position of dental implants as compared to conventional techniques using periapical and panoramic radiographs and a cast.     

Effect of sociodemographic variables on complete denture satisfaction

PURPOSE

The objective of this study was to evaluate the effect of sociodemographic factors on quality of satisfaction towards denture treatment.

MATERIALS AND METHODS

One hundred subjects (filling inclusion criteria) who were wearing a denture for at least two months were enrolled and divided into five groups on the basis of sociodemographic variables (age, gender, literacy level, socio-economic and marital status). Questionnaires consisting of 38 questions (positive and negative attitude towards denture satisfaction) related to patients'' perception of clinical outcome in different domains such as mastication, appearance, speech, comfort, health, denture care and social status were scored by the subjects. Questions reflecting positive attitude were scored as 2, 1, or 0 (yes, uncertain and no, respectively) and reversely for the negative questions. Statistical analysis was done by using Statistical Package for Social Sciences (α = .05).

RESULTS

Level of denture satisfaction was higher in age subgroup belonging to 45 - 65 years of age in relation to comfort, health and denture care. Female and male showed significant priority for denture treatment because of esthetic and function respectively. Level of satisfaction was statistically significant with literacy level. Upper high income group showed significantly higher level of satisfaction only in case of social status. Married group showed significantly higher satisfaction level only with comfort.

CONCLUSION

Patients'' sociodemographic variables were influential factors on denture satisfaction.     

Current biomedical waste management practices and cross-infection control procedures of dentists in India

Objectives: To investigate the knowledge, attitudes and behaviour of dentists working in dental clinics and dental hospitals regarding biomedical waste management and cross‐infection control. Methods: A national survey was conducted. Self‐administered questionnaires were sent to 800 dentists across India. Results: A total of 494 dentists responded, giving a response rate of 61.8%. Of these, 228 of 323 (70.6%) general dentists reported using boiling water as a sterilising medium and 339 (68.6%) dentists reported disposing of hazardous waste such as syringes, blades and ampoules in dustbins and emptying these into municipal corporation bins. Conclusions: Dentists should undergo continuing education programmes on biomedical waste management and infection control guidelines. Greater cooperation between dental clinics and hospitals and pollution control boards is needed to ensure the proper handling and disposal of biomedical waste.     

Normative bone mineral density data at multiple skeletal sites in Indian subjects

Summary

Age-related change in bone mineral density (BMD) varied according to skeletal site in Indian subjects. A larger proportion of subjects was classified as osteoporotic and osteopenic using the Caucasian database than newly derived peak BMD values at most skeletal sites. Results establish useful normative data for reliable interpretations of individual dual-energy X-ray absorptiometry (DEXA) values

Introduction

Osteoporosis is believed to occur at a relatively younger age in the Indian population. With increasing knowledge on significant differences in BMD between various racial groups, there is increased emphasis for the use of population-specific reference database.

Methods

BMD at multiple skeletal sites was measured using DEXA (Prodigy, Lunar) in 615 Indian women (20–86 years) and 489 Indian men (20–83 years). Best-fit models were drawn for each skeletal site. Osteopenia and osteoporosis diagnosis rates were calculated using Caucasian and derived Indian peak BMD values.

Results

Age-related change in BMD varied with skeletal site in both sexes. Peak BMD in women was observed between 31 and 40 years of age at the hip, spine, and radius 33% and between 20 and 30 years at the ultradistal radius. Peak BMD in men was attained between 20 and 30 years at the hip and radius 33% and between 31 and 40 years at the spine and ultradistal radius. A larger proportion of Indian subjects was classified as osteoporotic and osteopenic based on the Caucasian database than newly derived Indian peak BMD values at all skeletal sites except radius 33% and femoral neck in females above 40 years of age.

Conclusion

Results establish useful normative data for the Indian population for reliable interpretations of individual DEXA values.     

Injuries in amateur horse racing (point to point racing) in Great Britain and Ireland during 1993-2006

Objectives

To provide a breakdown of injury incidence from amateur jump racing (also known as point to point racing) in Great Britain and Ireland during 1993–2006 and to compare the injury epidemiology with professional horse racing in Great Britain, Ireland and France.

Design

Retrospective review.

Setting

Great Britain and Ireland.

Participants

Amateur jockeys.

Main outcome measures

Injury rates.

Results

Injury data suggest that point to point racing is more dangerous from an injury point of view than professional jump racing, which has previously been shown to be more dangerous than flat racing. Amateur jockeys have more falls than their professional counterparts, and this in turn puts them at greater risk of sustaining more serious injuries.

Conclusions

Amateur (point to point) jockeys represent a sporting population that previously has been little studied. They represent a group at high risk of injury, and hence formal injury surveillance tracking and counter measures for injury prevention are recommended.Horse racing is the most popular spectator sport throughout the world. In Great Britain, spectator numbers top five million annually, and major individual races like the Kentucky Derby in the US and the Melbourne Cup in Australia have television audiences estimated at over 500 million.In addition to professional horse racing, the various modes of amateur and recreational horse racing have high participation rates as well.¹This paper is designed to provide a breakdown of injury incidence from amateur jump racing (also known as point to point racing) in Great Britain and Ireland during 1993–2006 and to compare the injury epidemiology with professional horse racing in Great Britain, Ireland and France.^2,3 Comparison with professional racing will highlight the added risks inherent in point to point racing.     

Interactions between nitric oxide and corticosterone in the regulation of progenitor cell proliferation in the dentate gyrus of the adult rat.

It is well established that L-NAME, a generic NOS inhibitor, stimulates neurogenesis in the dentate gyrus of the adult rat and corticosterone reduces it. These experiments explore the interaction between L-NAME and corticosterone. L-NAME (50 mg/kg), as expected, increased proliferation, but also lowered plasma corticosterone levels. However, the stimulating action of L-NAME depends on the presence of rhythmic changes in plasma corticosterone, as it is abolished in rats treated with a subcutaneous implant of corticosterone, which flattens the diurnal rhythm. Adrenalectomized rats implanted with corticosterone also failed to respond to L-NAME. Giving them a single daily injection of corticosterone (2 mg/kg) in an attempt to replicate the diurnal rhythm restored the sensitivity of the progenitor cells to L-NAME. The mechanism for this result remains to be investigated. Excess corticosterone given by daily injection (40/mg/kg) reduced proliferation but did not alter the response to L-NAME, even though this occurred from a lower baseline. nNOS was demonstrable only in the inner (proliferative) layer of the dentate gyrus in control rats, and did not alter following excess corticosterone treatment. iNOS was detectable at low levels in control rats, but was increased markedly following corticosterone. eNOS was evident throughout the dentate gyrus, and also increased after corticosterone (particularly in the hilus). Aminoguanidine (100 mg/kg/day; an iNOS antagonist) significantly increased proliferation in corticosterone-treated rats (40 mg/kg/day) but not in controls without additional corticosterone, confirming that iNOS plays a role in corticosterone-regulated neurogenesis. Corticosterone may thus act on progenitor cells in part at least through increased nitric oxide (NO) formation. The effects of reduced NO on neurogenesis may rely on a dual mechanism: corresponding reductions in plasma corticosterone and increased induction of iNOS (and/or eNOS) within the dentate gyrus. The possibility that NO acts downstream of glucocorticoids in the dentate gyrus is suggested.     

Residual association at C9orf72 suggests an alternative amyotrophic lateral sclerosis-causing hexanucleotide repeat

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of motor neurons. Single-nucleotide polymorphism rs3849942 is associated with ALS, tagging a hexanucleotide repeat mutation in the C9orf72 gene. It is possible that there is more than 1 disease-causing genetic variation at this locus, in which case association might remain after removal of cases carrying the mutation. DNA from patients with ALS was therefore tested for the mutation. Genome-wide association testing was performed first using all samples, and then restricting the analysis to samples not carrying the mutation. rs3849942 and rs903603 were strongly associated with ALS when all samples were included (rs3849942, p = [3 × 2] × 10⁻⁶, rank 7/442,057; rs903603, p = [7 × 6] × 10⁻⁸, rank 2/442,057). Removal of the mutation-carrying cases resulted in loss of association for rs3849942 (p = [2 × 6] × 10⁻³, rank 1225/442,068), but had little effect on rs903603 (p = [1 × 9] × 10⁻⁵, rank 8/442,068). Those with a risk allele of rs903603 had an excess of apparent homozygosity for wild type repeat alleles, consistent with polymerase chain reaction failure of 1 allele because of massive repeat expansion. These results indicate residual association at the C9orf72 locus suggesting a second disease-causing repeat mutation.     

Association of testosterone and bone mineral density with tooth loss in men with chronic periodontitis

A study was conducted to compare the mean testosterone and bone mineral density (BMD) levels in men with and without tooth loss. Two hundred three male subjects aged 30-65 years satisfying the study criteria were selected and then examined for bone mineral density, testosterone level, clinical attachment loss, probing pocket depth, tooth mobility and tooth loss due to periodontal disease. Statistical analysis was performed using the Statistical Package for Social Sciences (version 15.0) (SPSS Inc., Chicago, Ill, USA), and differences were considered to be significant at P < 0.05. Independent sample "t" test was used to compare the results, and receiver-operator curve (ROC) analysis was performed to obtain the cut-off. The mean testosterone level in subjects without tooth loss was 4.41 ± 2.57, whereas that in subjects with tooth loss was 2.79 ± 1.15 (P = 0.001). The mean BMD in subjects without tooth loss was 0.99 ± 0.13, whereas that in subjects with tooth loss was 0.96 ± 0.12 (P = 0.046). The testosterone level and BMD in subjects with tooth loss were significantly lower than those in subjects without tooth loss. Testosterone is a good predictor of tooth loss, but its efficiency decreases with increasing tooth loss. BMD is not a good predictor of tooth loss.