Science of Dental Materials

The science of dental materials involves a study of the composition and properties of materials and the way in which they interact with the environment in which they are placed. The dentist spends much of his professional career handling materials and the success or failure of many forms of treatment depends upon the correct selection of materials possessing adequate properties, combined with careful manipulation. It is no exaggeration to state that the dentist and dental technician have a wider variety of materials at their disposal than any other profession.Many dental materials are fixed permanently into the patient’s mouth or are removed only intermittently for cleaning. Such materials have to withstand the effects of a most hazardous environment. Temperature variations, wide variations in acidity or alkalinity and high stresses all have an effect on the durability of materials.Selection of dental materials
The process of materials selection should ideally follow a logical sequence involving:• Analysis of the problem
• Consideration of requirements
• Consideration of available materials and their properties
• Choice of material.Evaluation of the success or failure of a material may be used to influence future decisions on materials’ selection. Many experienced practitioners carry out this sequence with no apparent effort since they are able to call upon a wealth of clinical experience. However, when presented with new or modified materials even the most experienced dentist should return to a more formal type of selection process based on the criteria mentioned.Evaluation of materialsAs the number of available materials increases, it becomes more and more important for the dentist to be protected from unsuitable products or materials which have not been thoroughly evaluated. It should be emphasized, however, that most manufacturers of dental materials operate an extensive quality assurance programmer and materials are thoroughly tested before being released to the general practitioner.Standard specifications: Many standard specification tests, of both national and international standards organizations, are now available which effectively maintain quality levels for some dental materials. Such specifications normally give details for the testing of certain products, the method of calculating the results of the minimum permissible result which is acceptable.Laboratory evaluations: Laboratory tests, some of which are used in standard specifications, can be used to indicate the suitability of certain materials. For example, a simple solubility test can indicate the stability of a material in aqueous media – a very important property for filling materials.Clinical trials: Although laboratory tests can provide important and useful data on materials the ultimate test is the randomized controlled clinical trial and the verdict of practitioners after a period of use in general practice. Many materials produce good results in the laboratory, only to be found lacking when subjected to clinical use.

Forgiveness – Philosophy or Science

Forgiveness is a wonderful act. Mystics, Saints and spiritual teachings all extol its merits. Instinctively, we all know at our core that forgiveness is a positive expression of spiritual living, but is forgiveness simply a nice philosophy to live by or does it hold some greater value, value underscoring a necessity, not preference, of its expression?Forgiveness means to for-give, i.e., to pardon, to cease to hold resentment, to cancel a debt. In other words, to forgive is to let go and not cling. We forgive others when they do us wrong because we want others to forgive us when we do them wrong. It’s the Golden Rule: Do unto others as you would have them do unto you.We also forgive because, in truth, we are the ones most negatively affected by the negative energy we cling to when we don’t forgive. As Saint Dariya of Bihar states, The sower of the poison cannot but be engulfed in the poison. In other words, “what we sow, we reap,” and “what goes around, comes around” – phrases depicting karma (the law of action and reaction). We all know, perhaps have even uttered, this sowing and reaping phrase, but do we actually live by it? Do we believe it? If we truly lived it, would we do the things we often do?The Karma/Reincarnation ConnectionHigh level mystic teachings inform us that reincarnation is a reality of life. Says Saint Sawan Singh: The principle of reincarnation is a fact. It is part of the Creator’s scheme. And here’s the critical rub: since what we sow, we reap, and since reincarnation is a fact of existence, then if we cling to another by holding on to resentments, then we are insuring a negative connection to that person which will bind us to him in the future. Being bound to him, we will have to meet him again in some future life to balance the karmic books. However, if we forgive him for whatever the act, then we let him go and release ourselves from having to be involved with him in some future time. We can then be free to keep climbing spiritually instead of being weighted down by the attachment we created by not letting go, i.e., not forgiving. Therefore, forgiveness progresses from being a nice philosophy to a law of life. In a nutshell, forgiveness frees us. By not forgiving, we remain attached to the perpetrator, enslaved energetically by the relationship and thereby deny our own spiritual freedom.Frankly, is it not true that if we do not forgive those who do us harm, then we become like them? Were this to happen, who would be in control, they or us? By not responding negatively to a negative act, we keep ourselves from being controlled by an outside force. If we do not react negatively to negative attacks but remain centered within ourselves, we remain in control, in charge of who and what we are. By this action of self-control, we plant virtuous, not poisonous, seeds. Thus, we cannot become engulfed by the poison we sowed, as Saint Dariya declares.SummaryIn summation, forgiveness is a spiritual law of liberation, not simply a pleasant formality or platitude. By not forgiving, we become chained. By forgiving, we become free. Therefore, non-forgiveness equates to slavery; forgiveness to freedom. In consideration of this knowledge, what will each of us choose the next time we are tested with situations involving forgiveness? Will we choose to forgive and be free, or will we choose not to forgive and become enslaved? Wisdom… and love… will dictate the answer.