History of resins in dentistry.

The period of 175 years from 1800 to 1975 represents one of significant advancement in prosthetic and restorative dental service. The transition from the time of ill-fitting dentures, fashioned from naturally occurring materials, to the application of synthetic resins for a long list of dental and surgical purposes described in this symposium represents a typical example of technical and professional advancement that has taken place throughout the world society during this same period. As noted in the beginning of this report, the advancement in dentistry has been possible through the cooperative efforts of contemporary scientists in many related fields. If denistry retains this good working relationship, as it is expected to do, then the advancements within the next two generations can significantly change and improve the practice of dentistry from what is presently known, by the application of additional new and modified dental resins.

Centenary year of scientific papers in the British Dental Journal.

This final part of the centenary series covers Kramer and McLean's paper, 'The response of the human pulp to self-polymerising acrylic restorations', which was one of the first papers to give such a detailed account and assessment of such changes. It is reviewed by Dr Graham Mount, who first met John McLean in 1973 and has worked closely with him since then.

History and current state of metal adhesion systems used in prosthesis fabrication and placement.

The adhesion techniques used in prosthetic dentistry have substantially improved with respect to retention of veneering resin to the metal framework of resin-veneered restorations and the bonding of resin-bonded fixed partial dentures (RBFPDs) to abutment teeth. In the early 1970s, prostheses relied on macromechanical retention for veneering surfaces and the retention holes of retainers. Later, retention was achieved by using small spherical particles. In addition, the use of small pits created by electrochemical corrosion was tested in resin-veneered restorations and RBFPDs. Thus, micromechanical retention gradually supplanted macromechanical retention. First-generation adhesive monomers were introduced at the end of the 1970s and were succeeded in the early 1980s by the marketing of adhesive resin cements, which were effective for use with non-noble alloys when surface oxidation procedures were used. In 1994, a second-generation adhesive primer for noble alloys was introduced, which prompted development of other adhesive primers. These primers were applied mainly to silver-palladium-copper-gold and type IV gold alloys and improved the reliability of RBFPDs. Recent studies have confirmed the effectiveness of such primers when used with high-gold-content metal ceramic alloys. Due to these developments, RBFPDs now have excellent esthetic characteristics.

Orthodontics in 3 millennia. Chapter 6: More early 20th-century appliances and the extraction controversy.

The trying conditions of the Great Depression and World War II did not deter innovative orthodontists from adding 3 new appliances to our armamentarium. Clinicians become fragmented into various technique "camps." Silas Kloehn's neck gear became a more patient-friendly version of extraoral anchorage, but it still had drawbacks. Angle's stranglehold on the specialty was finally broken when 3 of his disciples made extractions respectable.

A history of dental polymers.

The disadvantages of the use of vulcanite as a denture base material prompted the development of a wide range of thermoplastic polymers as alternatives to vulcanite. Heat-cured acrylic resin materials are the most widely used polymeric denture base materials at present, but research into further improvements in denture base materials continues.