The review presented here covers metastatic local and systemic disease secondary to the accumulation of plaque or the formation of other pathogenic microbial depots in the mouth. At least 3 pathways may link oral infection to secondary disease, to wit metastatic infection due to transient bacteremia, metastatic immunological injury, and metastatic toxic injury. The available evidence is presented and examples are provided. They concern among others such divergent diseases as acute bacterial myocarditis, infective endocarditis, brain abscess, uveitis and iridocyclitis, trigeminal and atypical facial neuralgia, unilateral facial paralysis, fever of "unknown' origin, and neutrophil dysfunction.

Summary. Thirteen preoperative and operative factors were investigated regarding their association with the incidence of postoperative pain after the first session of root canal treatment. The final analysis comprised 443 teeth of 443 patients. These were the teeth remaining after the original sample of 1204 teeth was reduced by the exclusion of all teeth associated with irrelevant factors which could possibly affect the analysis. The results showed that postoperative pain after the first visit occurred in 27 per cent of cases (5 per cent severe and 22 per cent moderate pain). Positive correlation occurred between the incidence of postoperative pain and several factors: the presence of preoperative pain in conjunction with a non‐vital pulp; the presence of a radiolucency larger than 5 mm in diameter; the number of root canals of the tooth treated; women reported more postoperative pain than men. Furthermore, the analysis revealed that the effects of these factors were cumulative.

Summary. The quality of root canal fillings in 172 single‐rooted extracted human teeth as it appeared on the buccal radiograph was assessed and compared with first that on a proximal radiograph, second the amount of linear dye penetration, and third the quality of adaptation and compaction of gutta‐percha observed in transverse root sections. The results justify the conclusion that the clinical radiograph has a limited correlation with first the quality of the root filling ascertained from a proximal radiograph, second dye penetration, and third the stereomicroscopic evaluation of filling adaptation and compaction in transverse root canals that are oval or ribbon‐shaped in transverse section are considered.

In this study the incidence of preoperative and postoperative pain of endodontic origin of 1204 teeth, treated by 10 dentists., was recorded. All endodontic treatments were completed in one visit except those where lack of time, continuing exudation or treatment to induce apexification did not permit it. The results show that postoperative pain occurred in approximately 29 per cent (7 per cent severe, 22 per cent moderate) of all visits and that there existed a strong positive correlation between the presence of preoperative pain and the incidence of postoperative pain. Based on this observation it is concluded that in studying postoperative pain after endodontic treatment knowledge of the preoperative status is a prerequisite. The results also showed that severe postoperative pain was usually reduced to a tolerable level within 3 days. Out of all treatments that were classified as emergency treatment the therapy chosen relieved the patient's pain in 35 per cent, while in 39 per cent it was reduced to moderate pain and in 14 per cent severe pain persisted. However, only 12 per cent of all these emergency treatments required further treatment.

Summary. Thermomechanical compaction was compared with lateral condensation by the use of radiographic examination and stereomicroscopic evaluation of transverse root sections for dye penetration etration and for adaptation of gutta‐percha. One hundred and twelve extracted single‐rooted teeth with curved root canals which were either round or oval to ribbon‐shaped in transverse sections were used. Under the condtions of this experiment performed in vitro, thermomechanical compaction proved to be significantly superior to laterl condensation on the aspects of radiographic appearance and the stereomicroscopic adaptation and compaction. With dye penetration no significant difference was found. Thermomechanical compaction resulted in better filling than lateral condensation, especially in the case of widely prepared oval or ribbon‐shaped root canals.