Mark Corson

By S. Sobota. Mid-America Nazarene University.

Finally the operator applied a bonding agent 60caps smok ox with amex, which penetrates into the primed dentine generic 60caps smok ox visa. One-bottle systems in which the primer and the bonding agent are combined within one solution are now on the market generic smok ox 60 caps. With such agents there is some evidence to suggest that patients may suffer a high incidence of postoperative sensitivity. There are also a few systems in the market, where the manufacturer has combined etch, prime, and bond solutions into a single solution. There is little independent research as yet to support these systems in relation to long-term performance, but initial results appear to indicate that there is very low postoperative sensitivity. The potential time-saving advantage would, of course, be welcome if researchers prove in the future that these systems provide high bond strength between the polymerized material and the dentine. Key Point New techniques and materials will always emerge in the market, but it is essential for the practitioner to be sceptical until researchers report clinical trials of adequate design and duration. Extrovert exponents of a particular technique or material frequently sway us into purchasing a material prematurely, but to our cost later. Glass ionomer cements This group of materials tend to be more brittle than composites, but have the advantage of adherence to both enamel and dentine without etching. The coefficient of expansion of glass ionomer is very close to that of dentine and once set, these materials remain dimensionally stable in the mouth despite constantly changing moisture and temperature levels. Their biggest advantage over composites is that they are able to release fluoride over an extended period of time. Resin-modified glass ionomer Reinforcement of glass ionomer with resin has been used to produce a fast setting cement but these materials require etching prior to placement. On modifying the materials, fracture toughness/resistance and abrasion resistance improve, and they still retain biocompatibility, fluoride ion hydrodynamics, favourable thermal expansion and contraction characteristics, and most important of all, they retain physico- chemical bonding to tooth structure. Compomer (polyacid-modified resin-based composite) These materials are a combination of composite and ionomer. They have better aesthetics than glass ionomer as a single material and have the advantage of some fluoride release, but there is still a need to etch during the restorative procedure. However, it would appear that they suffer from the disadvantages of loss of retention together with gap formation between the material and tooth substance. They also support remineralization techniques as an early intervention approach in approximal caries, where the lesion has not reached the dentine. Whichever way the clinician chooses to restore approximal caries, it will always entail loss of some sound tooth tissue. In approximal restorations, sufficient tooth preparation just to gain access to the carious dentine is necessary. Shape the outline form only to include the carious dentine and to remove demineralized enamel. Amalgam works well in these situations but clinicians are equally using composite resins more frequently in approximal restorations of young permanent teeth. Although there are some studies reporting good success rates, the overall consensus seems to be that tooth coloured restorations are prone to earlier failure than amalgam restorations. Operators should inform parents of this proviso when discussing the choice of restorative material. Rampant caries does occur in the permanent dentition as well as the primary dentition and once again treatment planning has to consider the person as a whole⎯indeed with children, sometimes the whole family⎯not just the teeth involved in one particular individual. This involves decision-making on • The advisability of restoration versus planned extraction. It is however, important to check for the presence and development of the second premolars before prescribing extraction of the first permanent molars since lack of the premolars necessitates all possible measures to attempt to retain the first permanent molars. The decision on extraction is dependent on the age of the child, the stage of development of the dentition, and the occlusion. Whereas there may be different treatment options with regard to carious first permanent molars, the clinician should usually attempt to retain incisors and/or canines, with extensive caries whenever possible. It may take up to 5 years after eruption for the root to complete its formation and develop an apical constriction. Key Point Whenever it is thought that caries removal might result in a pulpal exposure, efforts should be made to preserve pulp vitality in order to enable normal root maturation to occur. Indirect pulp capping If it is thought that exposure is likely to occur with full caries removal then sometimes it is expedient to leave caries in the deepest part of the lesion. Place a radio-opaque, biocompatible base over the remaining carious dentine to stimulate healing and repair. It is important to completely remove caries from all the lateral walls of the cavity before placement of a restoration since failure to do so will result in spread of secondary caries and the need for future intervention. Alternatives suggested include adhesive resins, and glass ionomer cements, but as yet there are no published studies looking at these techniques in permanent teeth. Whichever material is utilized, the crucial factor is to isolate the pulp well from the oral environment. Re-investigation of these teeth after about 6 months when the pulp has had an opportunity to lay down reparative dentine used to be recommended. However studies have found that the residual carious dentine mostly re-mineralizes and hardens and caries progression does not occur in the absence of micro-leakage. Returning to the operative site, to complete caries removal increases the risk of pulp exposure, therefore the authors consider it wiser to perform the indirect pulp capping and definitive restoration in one appointment. The direct pulp cap When a small exposure is encountered during cavity preparation the operator can place a direct pulp cap. Total etching and sealing with a dentine-bonding agent has been tried but this resulted in increased non-vitality, so it is now contraindicated.

The study of the appropriate uses of this process Clinical Practice Recommendation-12: The dental in assisting dentists and patients to arrive at the best profession smok ox 60 caps sale, together with all interested parties buy 60 caps smok ox overnight delivery, decisions needs renewed commitment cheap smok ox 60 caps visa. The poten- should increase efforts to convince the public as well tial of this approach along with possible misuses as local, state and national policymakers that fluor- need to be understood by dental practitioners, edu- idation of water supplies is a safe and cost-effective cators, researchers, and policymakers. The current meaning of evidence-based dentistry and its interpretation by practitioners, patients and With over 30,000 new cases and over 7,800 deaths policymakers are not the same. Confusion exists reported annually, oral cancer now accounts for and there is a barrier to the use and application of approximately 3% of all cancer deaths in the United evidence-based practice reviews. Creation and adop- States, a number which exceeds that of melanoma tion of uniform diagnostic codes on which to base evi- and cervical cancer. The dental profession must dence-based therapies will help eliminate the current make sure that every individual knows the impor- misapplications of evidence-based clinical practice. Enhanced under- will heighten the awareness of the risks of develop- standing of, and communication regarding, evidence- ing oral or pharyngeal cancer as well as the benefits based dentistry will help reduce the considerable of regular screening. Clinical Practice Recommendation-13: The dental Evidence-based practice involves the incorpora- profession should conduct intensive public service tion of such new knowledge into practices. However information and education efforts to reduce the death evidence-based practice also involves expertise on the rate due to oral cancer through early diagnosis. Given the changing oral disease patterns and treatment options, future clinical practice may be Clinical Practice Recommendation-15: Dental expected to incorporate more diagnostic-based data practitioners, educators, researchers and policymak- into treatment plans. Research and experience sug- ers should develop a common definition of evidence- gest that each patient presents different risk factors based practice. New diagnostic and patient choice to ensure the appropriate application treatment methodologies are available that would of the latest knowledge into the delivery of care. With scientific advances, methods and approaches to evaluation, diagnosis, and treatment planning will Clinical Practice Recommendation-19: A consortium change. Likewise, implementation of preventive inter- of representatives of dental practice, research, education, ventions as well as definitive therapy will evolve. However, outcomes assessments in dentistry are likely Prosthetic services will continue to be a large part of den- to remain incomplete in accuracy and scope until more tal practice. Given longer life expectancy and the inevi- broadly based diagnostic protocols are implemented. Scientific evidence, based The dentist must remain the repository of labo- on outcomes data, would broaden the base of knowledge ratory skill and knowledge. Dental school curriculums must maintain suffi- establish sound scientific application for outcomes, cient focus and resources to continue to prepare den- based on accurate diagnostic protocols. A short- age of qualified dental technicians will create a risk sit- A network of practitioners, assembled by the appro- uation in the areas of access and quality of care, espe- priate professional organizations and connected by cially for the financially disadvantaged populations. Clinical Clinical Practice Recommendation-20: A study should practitioners, to enhance their ability to monitor clin- be undertaken to address the adequacy of the number of ical and procedural protocols, should be able to access dental laboratory technicians and to develop a strategy unbiased and reliable information easily. Clinical Practice Recommendation-18: The dental Clinical Practice Recommendation-21: The dental profession should strive to develop the leading profession should develop strategies to maintain the repository of the most accurate dental diagnostic dentist as a knowledgeable director of laboratory and therapeutic databases. Higher medical costs and com- petitive pressures will lead to more defined contribu- Financing Recommendation-4: The dental profes- tion programs, more voluntary programs, greater sion should develop an active campaign to educate employee cost sharing, and optional coverage for employers and employees regarding dental benefits retirees. These changes will impact the use of dental choices so they can become better health care con- services and the mix of services. This campaign should include dentists as are simply a means of helping fund dental care. If these factors continue and are not corrected, they will Financing Recommendation-2: Financing of dental lead to growing dissatisfaction on the part of services should be structured so it will not inappro- patients; some may be unwilling to continue their priately interfere with the professional judgment of dental insurance plans. Changes in technology, dis- the dentist or create unwarranted intrusion into the ease patterns and demographics may stimulate decisions reached jointly by dentists and patients development of new dental benefit programs that regarding appropriate and best treatment options. These changes Radical changes in the health care delivery system could impact the types of services provided. In many cases this can be directly traced to unwar- ranted intrusion by third parties into the doctor/ Financing Recommendation-5: The dental profes- patient relationship. To remedy this situation na- sion should encourage the dental benefits industry tional legislators have sought to initiate actions that to streamline procedures, reduce administrative bur- would give Americans access to responsible care. A growing care within reasonable distances from their home; number of dentists are distancing themselves from and have the ability to pursue legal action against dental insurance companies proclaiming themselves to negligent health plans. If the dissatis- with regard to including them as reimbursable pro- faction becomes more widespread, it will negatively cedures in their plans. Carriers need to respond quickly to changing science and technology with Financing Recommendation-6: The dental profes- updated coverage that includes the more recent and sion should commence constructive dialogue with efficacious diagnostic and treatment modalities. However, providing access to For the long-term unemployed, adequate public dental care for all requires the cooperation of every financing is essential but currently, in most states, non- segment of society, including policymakers, the dental existent. Most dentists Kids Dental Program where funding does accommo- provide free or discounted care to people who other- date market level reimbursement and administration wise could not afford it. We as a society––policymakers, the dental in improved access to care for covered children. It is essential that the reimburse- The large majority of Americans can and do access ment fees for these services not fall below prevailing dental services, and the private delivery system provides market rates and thus, in the long term, should be high quality dental care for those who avail themselves indexed to assure that goal. However, for the numerous individuals who face date the anticipated increase in demand, these pro- barriers to care, commitment must be made to develop grams may have to be introduced incrementally, new and innovative approaches to facilitate access. Non-economic barriers to care for this population There are two large groups of people with low should be addressed such as cultural diversity, lan- incomes. One group consists of those with incomes guage, education and transportation needs. In 1996, this group consisted of 38 mil- Access Recommendation-1: Public funding should lion people, or 14% of the U.

Consultant obstetric and anaesthetic staff experienced in these conditions should be present cheap smok ox 60 caps with mastercard, and the cardiologist readily available safe 60caps smok ox. Rachael James All anticoagulant options during pregnancy are associated w ith potential risks to the m other and fetus smok ox 60 caps without prescription. Any w om an on w arfarin w ho w ishes to becom e pregnant should ideally be seen for pre- pregnancy counselling and should be involved in the anti- coagulation decision as m uch as possible. Potential risks to the fetus need to be balanced against the increased m aternal throm - botic risk during pregnancy. Anticoagulation for m echanical heart valves in pregnancy rem ains an area of som e controversy. The use of w arfarin during pregnancy is associated w ith a low risk of m aternal com plications1 but it readily crosses the placenta and em bryopathy can follow exposure betw een 6–12 w eeks’ gestation, the true incidence of w hich is unknow n. A single study has reported that a m aternal w arfarin dose 5m g is w ithout this em bryopathy risk. Conversion to heparin in the final few w eeks of pregnancy is recom m ended to prevent the delivery of, w hat is in effect, an anticoagulated fetus. Studies have been criticised for the use of inadequate heparin dosing and/or inadequate therapeutic ranges4 although a recent prospective study w hich used heparin in the first trim ester and in the final w eeks of pregnancy reported fatal valve throm boses despite adequate anticoagulation. Use in pregnancy is m ainly for throm boprophylaxis rather 100 Questions in Cardiology 201 than full anticoagulation but experience is increasing. M anagement W om en w ho do not w ish to continue w arfarin throughout preg- nancy can be reassured that conceiving on w arfarin appears safe but conversion to heparin, to avoid the risk of em bryopathy, needs to be carried out by 6 w eeks. Possible regim es include: • W arfarin throughout pregnancy until near term and then conversion to unfractionated heparin. Coum arin anticoagulation during pregnancy in patients w ith m echanical valve prostheses. Guidelines on the prevention, investi- gation and m anagem ent of throm bosis associated w ith pregnancy. Failure of adjusted doses of subcutaneous heparin to prevent throm boem bolic phenom ena in pregnant patients w ith m echanical cardiac valve prostheses. Matthew Streetly M echanical heart valves are associated w ith an annual risk of arterial throm boem bolism of <8%. This constitutes an unacceptable risk for patients undergoing m ajor surgery, and it is necessary to tem porarily institute alternative anticoagulant m easures. If surgery cannot be delayed, the effect of w arfarin can be reversed by fresh frozen plasm a (2–4 units) or a sm all dose of intravenous vitam in K (0. Recom m encing intravenous heparin in the im m ediate post- operative period m ay increase the risk of haem orrhage to greater levels than the risk of throm boem bolism w ith no anticoagulation. Heparin is usually restarted 12–24 hours after surgery, depending on the type of surgery and the cardiac reason for w arfarin. W arfarin should be restarted as soon as the patient is able to tolerate oral m edication. Marc R Moon The indications for surgical m anagem ent of endocarditis fall into six categories. Congestive heart failure Patients w ith m oderate-to-severe heart failure require urgent surgical intervention. W ith m itral regurgitation, afterload reduction and diuretic therapy can im prove sym ptom s and m ay m ake it possible to postpone surgical repair until a full course of antibiotic therapy has been com pleted. In contrast, acute aortic regurgitation progresses rapidly despite an initial favourable response to m edical therapy, and early surgical intervention is im perative. Persistent sepsis This is defined as failure to achieve bloodstream sterility after 3–5 days of appropriate antibiotic therapy or a lack of clinical im provem ent after one w eek. Recognised virulence of the infecting organism • W ith native valve endocarditis, streptococcal infections can be cured w ith m edical therapy in 90%. Fungal infections invariably require surgical intervention • W ith prosthetic valve endocarditis, streptococcal tissue valve infections involving only the leaflets can be cleared in 80% w ith antibiotic therapy alone; how ever, m echanical or tissue valve infections involving the sew ing ring generally require valve replacem ent. If echocardiography dem onstrates a perivalvular leak, annular extension, or a large vegetation, early operation is necessary 100 Questions in Cardiology 205 4. Extravalvular extension Annular abscesses are m ore com m on w ith aortic (25-50% ) than m itral (1-5% ) infections; in either case, surgical intervention is preferred (survival: 25% m edical, 60-80% surgical). Peripheral embolisation This is com m on (30-40% ), but the incidence falls dram atically follow ing initiation of antibiotic therapy. Surgical therapy is indicated for recurrent or m ultiple em bolisation, large m obile m itral vegetations or vegetations that increase in size despite appropriate m edical therapy. Cerebral embolisation O peration w ithin 24 hours of an infarct carries a 50% exacerbation and 67% m ortality rate, but the risk falls after tw o w eeks (exacer- bation <10% , m ortality <20% ). Follow ing a bland infarct, it is ideal to w ait 2–3 w eeks unless haem odynam ic com prom ise obligates early surgical intervention. Follow ing a haem orrhagic infarct, operation should be postponed as long as possible (4–6 w eeks). Peter Wilson Despite progress in m anagem ent, m orbidity and m ortality rem ain m ajor problem s for the patient w ith endocarditis, both during the acute phase and as the result of long term com plications after a bacteriological cure. Im provem ents in m icrobiological diagnosis, types of antibiotic treatm ent and tim ing of surgical intervention have im proved the outlook for som e patients but the im pact has been m inor w ith som e of the m ore invasive pathogens. Healed vegetations m ay leave valvular function so com prom ised that surgery is required. In 140 patients w ith acute infective endocarditis, 48 (34% ) required valve replacem ent during treatm ent. Recurrence w as observed in 5 (4% ) patients betw een 4 m onths and 15 years after the first episode. In the follow up period, another 16 patients died of cardiac causes, m ost w ithin five years. O f 34 patients w ith late prosthetic valve endocarditis, 27 (79% ) survived their hospital adm ission but 11 had further surgery during the next five years, usually follow ing cardiac failure.