Close contacts of xenograft recipients: Ethical considerations due to risk of xenozoonosis

With decades of pre-clinical studies culminating in the recent clinical application of xenotransplantation, it would appear timely to provide recommendations for operationalizing oversight of xenotransplantation clinical trials. Ethical issues with clinical xenotransplantation have been described for decades, largely centering on animal welfare, the risks posed to the recipient, and public health risks posed by potential spread of xenozoonosis. Much less attention has been given to considerations relating to potentially elevated risks faced by those who may care for or otherwise have close contact with xenograft recipients. This paper examines the ethical and logistical issues raised by the potential exposure to xenozoonotic disease faced by close contacts of xenotransplant recipients-defined herein as including but not limited to caregivers, household contacts, and sexual partners-which warrants special attention given their increased risk of exposure to infection compared to the general public. We discuss implications of assent or consent by these close contacts to potentially undergo, along with the recipient, procedures for infection screening and possible quarantine. We then propose several options and recommendations for operationalizing oversight of xenotransplantation clinical trials that could account for and address close contacts' education on and agency regarding the risk of xenozoonosis.

Revisiting the Use of Ulysses Contracts in Xenotransplantation

BACKGROUND

Xenotransplantation clinical trials may begin soon. A persistent risk of xenotransplantation, known for decades, is the possibility that a xenozoonotic infection could be transferred from a xenograft to its recipient and then to other human contacts. Because of this risk, guidelines and commentators have advocated for xenograft recipients to agree to either long-term or lifelong surveillance mechanisms.

METHODS

For the past few decades, one solution that has been proposed to ensure that xenograft recipients will comply with surveillance protocols is the use of a heavily modified Ulysses contract, which we review.

RESULTS

These contracts are most often used in psychiatry, and their application to xenotransplantation has been espoused several times with minimal criticism.

CONCLUSIONS

In this article, we argue against the applicability of Ulysses contracts in xenotransplantation based upon (1) the telos of the advance directive that may not be applicable to this clinical context, (2) the suspect nature of enforcing Ulysses contracts in xenotransplantation, and (3) the ethical and regulatory hurdles that such enforcement would require. Although our focus is on the US regulatory landscape in preparation for clinical trials, there are applications globally.

Extracorporeal cardiopulmonary resuscitation dissemination and integration with organ preservation in the USA: ethical and logistical considerations

Use of extracorporeal membrane oxygenation (ECMO) in cardiopulmonary resuscitation, termed eCPR, offers the prospect of improving survival with good neurological function after cardiac arrest. After death, ECMO can also be used for enhanced preservation of abdominal and thoracic organs, designated normothermic regional perfusion (NRP), before organ recovery for transplantation. To optimize resuscitation and transplantation outcomes, healthcare networks in Portugal and Italy have developed cardiac arrest protocols that integrate use of eCPR with NRP. Similar dissemination of eCPR and its integration with NRP in the USA raise novel ethical issues due to a non-nationalized health system and an opt-in framework for organ donation, as well as other legal and cultural factors. Nonetheless, eCPR investigations are ongoing, and both eCPR and NRP are selectively employed in clinical practice. This paper delineates the most pressing relevant ethical considerations and proposes recommendations for implementation of protocols that aim to promote public trust and reduce conflicts of interest. Transparent policies should rely on protocols that separate lifesaving from organ preservation considerations; robust, centralized eCPR data to inform equitable and evidence-based allocations; uniform practices concerning clinical decision-making and resource utilization; and partnership with community stakeholders, allowing patients to make decisions about emergency care that align with their values. Proactively addressing these ethical and logistical challenges could enable eCPR dissemination and integration with NRP protocols in the USA, with the potential to maximize lives saved through both improved resuscitation with good neurological outcomes and increased organ donation opportunities when resuscitation is unsuccessful or not in accordance with individuals' wishes.

Ventilator Triage Policies During the COVID-19 Pandemic at U.S. Hospitals Associated With Members of the Association of Bioethics Program Directors

BACKGROUND

The coronavirus disease 2019 pandemic has or threatens to overwhelm health care systems. Many institutions are developing ventilator triage policies.

OBJECTIVE

To characterize the development of ventilator triage policies and compare policy content.

DESIGN

Survey and mixed-methods content analysis.

SETTING

North American hospitals associated with members of the Association of Bioethics Program Directors.

PARTICIPANTS

Program directors.

MEASUREMENTS

Characteristics of institutions and policies, including triage criteria and triage committee membership.

RESULTS

Sixty-seven program directors responded (response rate, 91.8%); 36 (53.7%) hospitals did not yet have a policy, and 7 (10.4%) hospitals' policies could not be shared. The 29 institutions providing policies were relatively evenly distributed among the 4 U.S. geographic regions (range, 5 to 9 policies per region). Among the 26 unique policies analyzed, 3 (11.3%) were produced by state health departments. The most frequently cited triage criteria were benefit (25 policies [96.2%]), need (14 [53.8%]), age (13 [50.0%]), conservation of resources (10 [38.5%]), and lottery (9 [34.6%]). Twenty-one (80.8%) policies use scoring systems, and 20 of these (95.2%) use a version of the Sequential Organ Failure Assessment score. Among the policies that specify the triage team's composition (23 [88.5%]), all require or recommend a physician member, 20 (87.0%) a nurse, 16 (69.6%) an ethicist, 8 (34.8%) a chaplain, and 8 (34.8%) a respiratory therapist. Thirteen (50.0% of all policies) require or recommend that those making triage decisions not be involved in direct patient care, but only 2 (7.7%) require that their decisions be blinded to ethically irrelevant considerations.

LIMITATION

The results may not be generalizable to institutions without academic bioethics programs.

CONCLUSION

Over one half of respondents did not have ventilator triage policies. Policies have substantial heterogeneity, and many omit guidance on fair implementation.

PRIMARY FUNDING SOURCE

None.

A critical role for human caspase-4 in endotoxin sensitivity

Response to endotoxins is an important part of the organismal reaction to Gram-negative bacteria and plays a critical role in sepsis and septic shock, as well as other conditions such as metabolic endotoxemia. Humans are generally more sensitive to endotoxins when compared with experimental animals such as mice. Inflammatory caspases mediate endotoxin-induced IL-1β secretion and lethality in mice, and caspase-4 is an inflammatory caspase that is found in the human, and not mouse, genome. To test whether caspase-4 is involved in endotoxin sensitivity, we developed a transgenic mouse expressing human caspase-4 in its genomic context. Caspase-4 transgenic mice exhibited significantly higher endotoxin sensitivity, as measured by enhanced cytokine secretion and lethality following LPS challenge. Using bone marrow-derived macrophages, we then observed that caspase-4 can support activation of caspase-1 and secretion of IL-1β and IL-18 in response to priming signals (LPS or Pam3CSK4) alone, without the need for second signals to stimulate the assembly of the inflammasome. These findings indicate that the regulation of caspase-1 activity by human caspase-4 could represent a unique mechanism in humans, as compared with laboratory rodents, and may partially explain the higher sensitivity to endotoxins observed in humans. Regulation of the expression, activation, or activity of caspase-4 therefore represents targets for systemic inflammatory response syndrome, sepsis, septic shock, and related disorders.

Clinical efficacy in reducing dentin hypersensitivity of a dentifrice containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride compared to a dentifrice containing 8% strontium acetate and 1040 ppm fluoride under consumer usage conditions before and after switch-over

OBJECTIVE

The objective of this 16-week, double-blind, randomized, switch-over design study was to compare the efficacy in reducing dentin hypersensitivity of a dentifrice containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride as sodium monofluorophosphate (Colgate Sensitive Pro-Relief [also marketed as elmex Sensitive Professional]) to a desensitizing dentifrice containing 8% strontium acetate and 1040 ppm fluoride as sodium fluoride (Sensodyne Rapid Relief) under relevant consumer usage conditions.

METHODS

Qualifying subjects from the San Francisco, CA, USA area, who presented two hypersensitive teeth with a tactile hypersensitivity score (Yeaple Probe) between 10 and 50 grams of force and an air blast hypersensitivity score of 2 or 3 (Schiff Cold Air Sensitivity Scale), participated in this two-phase double-blind study. Subjects were randomly assigned to one of two test groups. The first phase of the study consisted of twice-daily at-home brushing with the first assigned dentifrice for eight weeks. The second phase of the study consisted of switching product use to the second assigned dentifrice for a second eight-week period. Dentin hypersensitivity examinations, which comprised tactile and air blast hypersensitivity measures, as well as examinations of oral hard and soft tissues, were conducted at baseline, at the completion of the first study phase, and at two weeks and eight weeks of the second phase.

RESULTS

One-hundred and twenty-one subjects complied with the study protocol and completed the study. Study Phase I: Subjects who brushed twice daily for eight weeks with the arginine/calcium carbonate dentifrice experienced statistically significant improvements in mean tactile and air blast hypersensitivity scores (51.3% and 39.4%, respectively) relative to that experienced by subjects who brushed with the strontium acetate dentifrice. Study Phase II: Subjects who brushed with the arginine/calcium carbonate dentifrice for the first eight weeks of the study and then switched to brush with the strontium acetate dentifrice for the second eight weeks of the study, did not exhibit further improvements in mean tactile or mean air blast hypersensitivity scores after two and eight weeks of switch-over product use. However, subjects who brushed with the strontium acetate dentifrice for the first eight weeks of the study and then switched to brush with the arginine/calcium carbonate dentifrice exhibited statistically significant improvements in mean tactile and air blast hypersensitivity scores two weeks (35.2% and 29.9%, respectively) and eight weeks (40.3% and 35.3%, respectively) after product switch-over. Relative to the subjects who switched from twice-daily brushing with the arginine/calcium carbonate dentifrice to brush with the strontium acetate dentifrice, those who switched from brushing with the strontium acetate dentifrice to brush with the arginine/calcium carbonate dentifrice exhibited statistically significant improvements in mean tactile hypersensitivity scores (10.3%) and in mean air blast hypersensitivity scores (16.3%) eight weeks after product switch-over.

CONCLUSION

Eight weeks of brushing with Colgate Sensitive Pro-Relief(elmex Sensitive Professional) provides significant reductions in mean dentin hypersensitivity relative to the identical use of Sensodyne Rapid Relief. Additionally, the dentin hypersensitivity reductions achieved by twice-daily brushing with Sensodyne Rapid Relief are significantly improved by switching to twice-daily brushing with Colgate Sensitive Pro-Relief (elmex Sensitive Professional) for two and eight weeks. Further, the dentin hypersensitivity reductions achieved by twice-daily brushing with Colgate Sensitive Pro-Relief (elmex Sensitive Professional) are not improved by switching to twice-daily brushing with Sensodyne Rapid Relief for two or eight weeks. Eight weeks' use of Colgate Sensitive Pro-Relief (elmex Sensitive Professional), after having used Sensodyne Rapid Relief for an initial eight-week time period, provides statistically significant improvements in dentin hypersensitivity relative to eight weeks' use of the Sensodyne Rapid Relief.

The clinical effect of a single direct topical application of a dentifrice containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride on dentin hypersensitivity: the use of a cotton swab applicator versus the use of a fingertip

OBJECTIVE

The primary objective of this examiner-blind, randomized clinical study was to compare the effect of a toothpaste containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride, as sodium monofluorophosphate (MFP), in providing instant relief of dentin hypersensitivity when delivered as a single direct topical application using a cotton swab applicator versus using a fingertip. A secondary objective was to evaluate the effect on dentin hypersensitivity of the dentifrice after seven days of twice-daily at-home brushing, subsequent to the single direct topical application performed at the beginning of the study.

METHODS

Qualifying subjects possessed two baseline-designated hypersensitive teeth with a tactile hypersensitivity score of 10 to 50 grams of force (Yeaple Probe), and an air blast hypersensitivity score of 2 or 3 (Schiff Cold Air Sensitivity Scale). In the first phase of the study, subjects topically self-applied the test product using a fingertip, a previously validated method, for one of the hypersensitive teeth (fingertip test teeth), and a cotton swab applicator for the second hypersensitive tooth (swab test teeth). In the second phase of the study, subjects brushed with the test dentifrice twice daily for seven days. Dentin hypersensitivity assessments, as well as examinations of oral hard and soft tissues, were conducted immediately after direct topical product application, and after the subsequent seven-day brushing period.

RESULTS

Eighty-four subjects complied with the study protocol and completed the study. Immediately after direct topical application, the fingertip test teeth and the swab test teeth exhibited statistically significant (p <0.05) improvements from baseline in mean tactile hypersensitivity scores (191.7% and 182.1%, respectively), and mean air blast hypersensitivity scores (58.1% and 56.3%, respectively). After the seven-day brushing period, the fingertip test teeth and the swab test teeth continued to exhibit statistically significant (p < 0.05) improvements from baseline in mean tactile hypersensitivity scores (191.7% and 190.5%, respectively) and mean air blast hypersensitivity scores (57.4% and 58.2%, respectively). No statistically significant (p > 0.05) differences were indicated between the fingertip test teeth and the swab test teeth with respect to mean tactile hypersensitivity scores or mean air blast hypersensitivity scores immediately after topical application (3.4% and 4.4%, respectively), or after seven days of twice-daily brushing with the product (0.41% and -1.90%, respectively).

CONCLUSION

The results of this examiner-blind clinical study support the conclusions that 1) both fingertip and cotton swab methods of application provide significant reductions in dentin hypersensitivity immediately after a single direct topical application of the 8.0% arginine-calcium carbonate dentifrice, 2) when topical application is followed by seven days of twice-daily brushing with the dentifrice, the sensitivity relief obtained instantly after topical application is maintained, and 3) after topical application and after seven days of brushing, neither method of topical application provided a level of control of dentin hypersensitivity that differed significantly from the other.

Clinical efficacy of an optimized stannous fluoride dentifrice, Part 4: A 3-month calculus clinical study, northwest USA

The objective of this 3-month, double-blind study was to investigate the efficacy of Colgate Optimized Stannous Fluoride (COSF) dentifrice for the control of supragingival dental calculus accumulation. After 3 months' use, the COSF dentifrice group exhibited a statistically significant 56.6% reduction in supragingival calculus formation, as compared to the control dentifrice group. The results of this study support the conclusion that the COSF dentifrice is efficacious for controlling the accumulation of supragingival calculus.

Effects of liquid nitrogen cryotherapy and bone grafting on artificial bone defects in minipigs: a preliminary study

Liquid nitrogen cryotherapy has been advocated as an adjunct in the enucleation and curettage of locally aggressive lesions of the jaws. Simultaneous autogenous bone grafting has also been advocated to accelerate bone formation and reduce morbidity. There is, however, relatively little scientific basis for either of these hypotheses. In this study, nine Yucatan minipigs had artificial defects created in the mandible, which were treated with liquid nitrogen spray. Half of the defects were grafted with autogenous bone from the chin and half were closed primarily. Two animals were sacrificed 3 days postoperatively to measure the width of necrosis and the rest were sacrificed at 3 months to assess healing and new bone formation. It was found that drilling the artificial defects alone caused bone necrosis for a mean depth of 0.09 mm. Liquid nitrogen cryospray caused a mean depth of bone necrosis of 0.82 mm (range 0.51-1.52 mm). The defects that were bone grafted healed well clinically. Defects not bone grafted showed a 50% rate of wound breakdown and sequestrum formation with delayed healing. Vital staining showed a non-significantly greater rate of bone formation in the grafted defects. Digitally superimposed radiography showed a non-significantly greater bone density in the non-grafted defects at 3 months postoperatively. It appears that liquid nitrogen cryospray does devitalize an area of bone around defects in the mandible. The width of necrosis is usually less than 1 mm and subsequent healing is enhanced by autogenous bone grafting. This has clinical implications.

A randomized clinical trial of the desensitizing efficacy of three dentifrices

The effect on dentinal hypersensitivity from the use of a new dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength Toothpaste, Colgate-Palmolive Co.) over an 8-week period was compared to a commercially available dentifrice containing 5.0% potassium nitrate and 0.243% sodium fluoride in a silica base (positive control [Sensodyne Fresh Mint Toothpaste, Block Drug Company, Inc.]) and to a commercially available nondesensitizing dentifrice containing 0.243% sodium fluoride in a silica base (negative control [Colgate Winterfresh Gel, Colgate-Palmolive Co.]). A total of 120 participants were stratified into 3 balanced groups according to baseline mean air blast (thermal) and tactile (Yeaple Probe) sensitivity scores, gender, and age. Participants brushed their teeth twice daily (morning and evening) for 1 minute. Dentinal hypersensitivity examinations were conducted at baseline, 4 weeks, and 8 weeks by the same dental examiner. After 4- and 8-weeks' use of their assigned products, participants in the new dentifrice group demonstrated statistically significant improvements (p < 0.05) in tactile and air blast sensitivity, as compared to those using the positive and negative control dentifrices.

Desensitizing efficacy of a new dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride

PURPOSE

To evaluate the relative effectiveness provided by a new dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength) for reducing dentin hypersensitivity over an 8-wk period, as compared to that provided by a commercially-available antihypersensitivity dentifrice containing 5.0% potassium nitrate and 0.76% sodium monofluorophosphate in a dicalcium phosphate base (Fresh Mint Sensodyne dentifrice).

MATERIALS AND METHODS

To qualify for participation in this examiner-blind study, male and female adults from the San Francisco, California area were required to present with tactile and air blast dentin hypersensitivity in at least 2 non-molar teeth at two examinations, spaced 1 wk apart. Qualifying subjects were randomized into two treatment groups, which were balanced for gender, age, and baseline sensitivity scores. Subjects were provided with a soft-bristled toothbrush. Examinations for tactile and air blast sensitivity were repeated after 4 wks' use of the study dentifrices, and again after 8 wks' usage.

RESULTS

101 subjects complied with the protocol, and completed the entire study. After 4 wks, subjects assigned to the Colgate Sensitive Maximum Strength group exhibited a statistically significant improvement over the Fresh Mint Sensodyne dentifrice group with respect to tactile sensitivity scores, and a statistically significant improvement over the Sensodyne dentifrice group with respect to air blast sensitivity scores. Correspondingly significant improvements were presented after 8 wks. Thus, the results of this examiner-blind clinical study support the conclusion that Colgate Sensitive Maximum Strength dentifrice provided superior levels of control of tactile and air blast sensitivity than did the clinically tested, commercially-available Sensodyne anti-hypersensitivity dentifrice.

Efficacy of a dentifrice containing 5% potassium nitrate and 1500 PPM sodium monofluorophosphate in a precipitated calcium carbonate base on dentinal hypersensitivity

The effect on dentinal hypersensitivity from the use of a dentifrice containing 5.0% potassium nitrate, 1500 ppm sodium monofluorophosphate in a precipitated calcium carbonate (PCC) base over an eight-week period was compared to a placebo dentifrice without potassium nitrate. A total of forty-eight subjects were entered into the study and stratified into two balanced groups according to their baseline mean thermal (air blast) and tactile (Yeaple Probe) sensitivity scores. The two groups were randomly assigned to use either the potassium nitrate/PCC dentifrice or a placebo dentifrice without potassium nitrate. The two groups were well balanced with regard to their mean baseline thermal tactile sensitivity scores, sex and age. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice and a commercially available soft-bristled toothbrush. Dentinal hypersensitivity examinations, which included tactile and thermal sensitivity, were conducted at baseline, four weeks, and eight weeks. Examinations were conducted by the same dental examiner (TS) on the subjects at each examination. After four weeks' use of their assigned products, those subjects in the potassium nitrate/PCC dentifrice group demonstrated statistically significant improvements (p < 0.0001), as compared to the placebo dentifrice without potassium nitrate, in tactile and thermal sensitivity. After eight weeks' use of their assigned products, those subjects in the potassium nitrate/PCC dentifrice group again demonstrated statistically significant improvements (p < 0.0001), in tactile and thermal sensitivity, as compared to the placebo dentifrice without potassium nitrate. Thus it can be concluded from this study that the use of a dentifrice containing 5.0% potassium nitrate and 1500 ppm sodium monofluorophosphate in a precipitated calcium carbonate (PCC) base is a clinically effective method for reducing dentinal hypersensitivity.

Adherence of two film-forming medications to the oral mucosa

This study provides a comparison among 10 patients of old and new formulas of Zilactin (Zila Pharmaceuticals, Phoenix). The original formula contained tannic acid; the new formula replaced tannic acid with benzyl alcohol as the active ingredient. The U.S Food and Drug Administration's (FDA) ruling that tannic acid must be eliminated as the active ingredient from the Zilactin formula was the reason for the change. In the study, no side effects were reported for either formula, except for a minor burning sensation at the time of application. Moreover, the new Zilactin formula, on average, provided a statistically significant rate of adherence of 21 percent to the oral mucosa.

The comparative efficacy of two commercial tartar control dentifrices in preventing calculus development and facilitating easier dental cleanings

Tartar control dentifrices have been proven effective in reducing the build-up of supragingival calculus deposits between professional tooth cleanings. In addition to providing consumers with a cleaner dentition, these formulations can, in principle, contribute to easier professional tooth cleaning. Until recently, clinical methods for evaluating the effects of tartar control dentifrices were limited to the assessment of area coverage of calculus on the tooth surface. The development of the Quanticalc dental scaler permits the quantitative clinical measurement of force and stroke number associated with supragingival calculus debridement. In this clinical study, two commercial tartar control dentifrices, one containing 5.0% pyrophosphate as the tartar control agent and the other containing a combination of 1.3% pyrophosphate and 1.5% Gantrez copolymer, were compared for efficacy in reducing the development of supragingival calculus between prophylaxes, and in facilitating easier calculus removal in subsequent scaling. Results showed that the two commercial dentifrices were equally effective in reducing calculus extent between prophylaxes. In contrast, the 5.0% pyrophosphate dentifrice was observed to be almost twice as effective on a percentage basis as the lower dosage pyrophosphate dentifrice in facilitating easier calculus removal. The enhanced activity of the 5.0% pyrophosphate dentifrice may be postulated to be due to elevated dosage of tartar control crystallization inhibitor or to potential side effects of copolymer in the other commercial dentifrice. Importantly, these results substantiate that the clinical benefits of tartar control dentifrices are not completely described by actions in reducing calculus build-up as assessed by VMI, and that important clinical benefits and differences in efficacy may be provided by these formulations in facilitating easier dental cleaning of supragingival calculus.

Anticalculus efficacy of three dentifrices

PURPOSE

To evaluate the anticalculus effect of three commercial dentifrices.

MATERIALS AND METHODS

A 12-week independent and double-blind clinical study was conducted on a population of calculus-forming adult male and female subjects in Budapest, Hungary to directly compare the anticalculus efficacy of three commercially-available dentifrices, as compared to a placebo dentifrice. The three commercially-available anticalculus dentifrices compared in this clinical study to a 0.243% sodium fluoride/silica placebo dentifrice were as follows: (1) A dentifrice containing 1.3% soluble pyrophosphate and 1.5% of a PVM/MA copolymer in a 0.243% sodium fluoride/silica base. (2) A dentifrice containing 0.3% triclosan and 2% of a PVM/MA copolymer in a 0.243% sodium fluoride/silica base. (3) A dentifrice containing 0.3% triclosan and 0.75% zinc citrate in a 1.14% sodium monofluorophosphate/silica base.

RESULTS

All three anticalculus dentifrices provided statistically significant reductions in supragingival calculus formation, as compared to a placebo dentifrice, after 12 weeks of use. The reductions in supragingival calculus formation ranged from 39% to 55%, as compared to a placebo dentifrice, for the three commercially-available anticalculus dentifrices. There was no statistically significant difference among the three commercially-available dentifrices with regard to anticalculus efficacy.

Photography without film: low-cost digital cameras come of age in dermatology

BACKGROUND

Photography is integral to the practice of dermatology. Digital imaging techniques have only recently been used to assess cutaneous disorders. Previously reported imaging systems have been both expensive and cumbersome. Consequently, they have failed to gain wide-spread acceptance.

METHODS

We describe our experience using an inexpensive digital camera. Photographs taken with this portable digital camera (FotoMan) compare favorably to those obtained with conventional 35 mm cameras.

RESULTS

This inexpensive digital camera provides photographs of acceptable quality for a variety of dermatologic applications. Images created with this system are available within minutes and are less expensive than traditional photographs.

CONCLUSIONS

Digital imaging is a new and exciting development. The digital camera described is simple to operate and provides a useful alternative or adjunct to conventional photography.

Four clinical studies comparing the efficacy of flat-trim and multi-level trim commercial toothbrushes

Four independent clinical studies were conducted to compare the short- and long-term effectiveness of three commercially available toothbrushes. Two of the four studies compared plaque removal in a single-use, crossover design, and two studies compared plaque and gingivitis reduction efficacy for a long-term, three-month use. The Turesky modification of the Quigley-Hein Plaque Index and the modified Gingival Index were used to assess plaque and gingivitis levels, respectively. The two long-term studies directly compared the Oral-B P-35 and Crest Complete toothbrushes, while the two single-use studies compared the Oral-B P-35, Crest Complete and Colgate Precision toothbrushes. In all four studies, there were no significant differences found between any of the toothbrushes.

Effects of two fluoride dentifrices containing triclosan and a copolymer on calculus formation

A 12-week, double-blind, parallel and unsupervised clinical study was conducted to compare the effects on supragingival calculus formation of two dentifrices containing triclosan (Irgacare MP) and a copolymer of methoxyethylene and maleic acid (Gantrez) as compared to a placebo dentifrice. All 147 adult male and female subjects completed the study. Subjects were stratified into three balanced groups on the basis of their Volpe-Manhold index calculus scores as obtained from a 3-month pre-test period using a placebo dentifrice. After a complete oral prophylaxis, subjects were assigned to the use of either the placebo dentifrice, a dentifrice containing 0.3% triclosan and 2.0% of a copolymer in a 0.243% sodium fluoride silica base, or a dentifrice containing 0.3% triclosan and 2.0% of a coplymer in a 0.76% sodium monofluorophosphate alumina base. Subjects, after brushing with their assigned dentifrice and soft-bristled toothbrush for 12 weeks, were evaluated by the examining dentist for supragingival calculus formation using the Volpe-Manhold assessment method. These examinations showed that the dentifrice containing 0.3% triclosan/2.0% copolymer in a 0.243% sodium fluoride silica base reduced supragingival calculus deposits by 23.12% and the dentifrice containing 0.3% triclosan/2.0% copolymer in a 0.76% sodium monofluorophosphate alumina base reduced supragingival calculus deposits by 26.15%. Both of these reductions in supragingival calculus were compared to the placebo dentifrice and were statistically significant at the 99% level of confidence.

Interpretation of bitewing radiographs: application of the kappa statistic to determine rater agreements

The interrater agreement of 34 dentists in determining the presence or absence of caries and the depth of caries in bitewing radiographs was studied. The kappa statistic was used to determine rater agreement, and results indicate that there was substantial agreement on the presence or absence of caries and only fair agreement on the specific depth of caries. Because of the degree of disagreement in determination of the extent of caries among examiners, it is recommended that this fact be taken into account in relation to the findings on bitewing radiographs, particularly when there may be differences of opinion between parties.

The historical profile

Sir William Osler once said one should "never treat a stranger." His statement is especially applicable to the practice of dentistry in which the physical and emotional stability of the patient is determined primarily by using the medical history. However, patients do not always appreciate the significance of medically related questions asked by a dentist. The accomplished clinician must, therefore, not only master the science of inquiry and the art of observation but must also establish the rapport that precedes the unguarded flow of pertinent information from the patient. This information is germinal to successful treatment.

A two-year clinical study comparing the effect of dentifrices on selected dental materials

1 A two-year double-blind human clinical study has been conducted to determine the comparative effect of two commercially available dentifrices on selected dental materials. 2 Forty-three adult subjects were selected to participate. They received either acrylic resin or silicate restorations in their anterior teeth, or a full cast gold veneer crown with an acrylic surface. 3 The subjects were randomly assigned to either one of the two dentifrices and utilized the dentifrice in their normal manner at least 3 times per day. 4 The dental restorations were clinically evaluated in reference to their surface characteristics immediately after placement, and after 3, 6, 12 and 24 months' use of the dentifrices. The acrylic surfaces of the veneer crowns were also evaluated at these same time periods; however, in this case an in vivo tooth surface reflectance measurement technique was also utilized. 5 The results of this clinical study provide the following conclusion after 24 months use of the two dentifrices: There was no difference between the two dentifrices in that neither dentifrice produced any abnormal or unusual effect on the surface characteristics of either the acrylic or silicate anterior restorations, or the acrylic surfaces of the veneer crowns.