The present investigation recorded the 2-year clinical and radiographic outcome of one- and two visit endodontic treatment and studied the significance of the bacteriologic sampling results on the outcome. A randomization procedure allocated 53 teeth to one-visit treatment and 48 teeth to two-visit treatment. At the end of the study period, 32 teeth (65%) in the one-visit group and 30 teeth (75%) in the two-visit group were classified as healed. The statistical analysis of the healing results did not show any significant difference between the groups (p=0.75). Forty-nine (80%) of the 61 teeth that were obturated after a negative micobiologic sample were classified as healed. Teeth sealed after positive samples healed in 44%. The present study gave evidence that similar healing results might be obtained through one- and two-visit antimicrobial treatment.

Objective. Outcome of pulpectomy in 2 treatment sessions with calcium hydroxide as an intracanal dressing was compared to a procedure comprising instrumentation and root-filling in 1 session.Study design. Subjects with a vital pulp condition (N = 256) were recruited to a randomized clinical trial. Outcome parameters included radiographic signs of apical periodontitis and painful symptoms at clinical follow-ups 1 week and 1-3 years after treatment.Results. Of 244 subjects available for final recall, 17 presented with periapical radiolucency. Lesions were evenly distributed among the 2 treatment groups. Postoperative pain recorded I week after permanent filling was significantly associated with overfilling (P = .001), with no difference between treatment groups. There was no association with presence of overfilling and radiographic lesion at end point of recall.Conclusions. Study confirms that pulpectomy may be carried out at a high rate of success if due attention is given to aseptic operating procedures, proper instrumentation and filling. Under these conditions an interappointment dressing with calcium hydroxide does not seem to influence outcome.

The presence of stainable bacteria under restorations and pulp reactions in 36 teeth restored in vivo with a modified Class II composite resin restoration with two different dentine treatment techniques were studied on three separate follow-up occasions (1-3, 7-10 and 28-32 days). Half of the cavities showed stainable bacteria at the cavity margins and bottoms. Teeth restored with method A (Gluma/Occlusin) showed significantly fewer restorations with stainable bacteria then teeth restored with method B (Life/Occlusin) (p less than 0.05). Significantly more restorations with detectable bacteria were found after 28-32 days and restorative method B (p less than 0.05). There were no differences in occurrence and grade of pulp inflammation for the different dentine treatment techniques and time periods.

Marginal adaptation and bacterial penetration were studied in 32 primary molars filled with composite resin in shallow class II cavities. The restorations had served in the mouth for 3 years (mean, 3 years and 4 months; range, 8 months to 6 years and 4 months). Ground sections of the retrieved teeth were evaluated with polarized light microscopy and demineralized sections with light microscopy. Clinically excellent restorations, free from bacteria, were found in 25%. Gaps were recorded in 42%, under- or over-contouring and porosities in 95%, caries in the cervical area in 58%. Bacteria were observed subjacent to the fillings in 75% and in the dentin tubules in 61%. Pupal necrosis was found in 7 of 16 teeth. Marginal discoloration, visible crevice, or color mismatch was associated with marginal defects, bacterial leakage, and pulpal reactions.

Twenty-six teeth with crown-root fractures have been subjected to intraalveolar transplantation. In 13 teeth the endodontic treatment was instituted before transplantation and in another 13 teeth 3-4 weeks after transplantation. Bacteriological tests showed that endodontic treatment after transplantation was preferable with statistically fewer treatments and more reliable results. The results thus points in favour of a late endodontic treatment with controlled aseptic conditions.

Mandibular bone resorption was studied in patients treated with tissue-integrated prostheses (TIP) and in complete-denture wearers by distance and area measurements on cephalometric radiographs. The area measurements were performed by means of a computer. Two TIP groups with short and long periods (mean = 2.4 and 23.9 years) of edentulousness and wearing complete dentures before fixture installation were followed up over 7-8 years. Mandibular bone resorption was remarkably small behind the distally positioned fixtures in comparison with the corresponding region in complete-denture wearers. Patients with complete dentures showed a continuous resorption of the mandibular alveolar ridge over 21 years, even though there were great individual variations. The bone loss was most pronounced anteriorly and during the first 2 years after extraction of the residual teeth. It is concluded that treatment with tissue-integrated prostheses seems to reduce bone resorption in the mandible, probably owing to favorable load conditions and adequate stimulation of the bone.

Summary. The purpose of the present study was to test the hypotheses that calcium hydroxide enhances pulpal protection against irritating substances in and around dental restorations when topically applied to cut dentine, and to acquire further information regarding the possible mechanisms involved. Cavities in dentine were treated for 30 days with either a water slurry of calcium hydroxide or a hard‐setting calcium hydroxide containing base. Control cavities were treated with saline. The additional effect of dry cutting prior to the restoration was also included as a control. Pulpal responses after placement of a silicate cement restoration were evaluated after an additional period of 30 or 150 days. From histological sections the volumes of inflamed pulp and the volumes of irregular secondary dentine were calculated with a morphometric method of evaluation. Changes in dentine to the calcium hydroxide treatment were observed with scanning electron microscopy. Most pulps in teeth with cavities treated with saline and restored for 30 days with silicate cement exhibited inflammatory alterations. Calcium hydroxide treated teeth had a significantly lower volume of inflamed pulp compared with the saline controls. Dry preparation was also associated with reduced inflammatory reaction. Pulps in teeth with dentine treated by the calcium hydroxide containing hard‐ setting base displayed the same magnitude of pulpal inflammation as the saline treated controls. After restoration for 150 days the volumes of inflamed pulp tissue were reduced in all treatment groups, however the least pulpal responses were found in teeth treated with calcium hydroxide slurry. Data also showed that the calcium hydroxide treatment was associated with only small volumes of irregular secondary dentine, while in contrast dry cut teeth showed large volumes of irregular secondary dentine. Scanning electron microscopic evaluation of dentine treated with calcium hydroxide revealed reticular structures inside the dentinal tubules

The most common method of evaluating pulp tissue reactions to injury is by a qualitative assessment of pulp tissue alterations. This evaluation method is subjective and difficult to quantify; stereological methods are more suitable, for they can quantify important tissue components, and so more objectively describe pulp tissues. This study compares a morphometric and a descriptive method of classification for pulp tissue analysis by using 15 teeth with inflamed pulp tissue, and 12 teeth experimentally pulp-capped with calcium hydroxide. Morphometric analysis allowed for volumes of remaining dentin, pulp tissue, inflamed pulp tissue, and reparative dentin to be calculated. In addition, volume densities of polymorphonuclear and mononuclear leukocytes, odontoblasts, fibroblasts, erythrocytes, vessels, and residual tissue were calculated for comparison among different experimental teeth. The morphometric method provided a quantitative description of tissue reactions. The descriptive method of classification was adequate when inflamed tissue subjacent to the cavity was evaluated, but was less precise than the morphometric method in describing reactions deeper in the tissue. The descriptive method could delineate the amounts and types of inflammatory cells only in non-quantified terms, while the morphometric method could quantify and locate them. It also yielded a quantified evaluation of the healing sequence of experimentally pulp-capped teeth. In conclusion, a morphometric method can yield more quantitative data on pulp tissue reactions than can a descriptive method of classification.

Abstract Intra‐ and extracellular products from oral bacteria were placed in Class V cavities prepared in dentin of human and monkey teeth to compare initial and late pulp tissue reactions. In one set of teeth, the bacterial material was left in the cavities for the entire experimental period (4, 10, 30 d in monkeys, 30 d in humans). In other teeth the challenge was stopped after 32 h and the bacterial material was removed and substituted with zinc‐oxide eugenol cement. The subsequent pulp tissue responses were observed histologically after 4, 10 (monkeys) and 30 d (humans and monkeys). Thirty‐two hours of bacterial challenge to human teeth induced intense acute inflammatory lesions. Four days of challenge in monkeys resulted in severe inflammatory cell involvement and pulpal necroses in a few teeth. At extended periods of observation severe inflammatory lesions were less frequent and the majority of the pulps showed tissue repair and healing at 30 d. This occurred irrespective of experimental protocol. Fourteen of 84 monkey teeth and none of 17 human teeth presented pulp tissue necrosis at follow‐up. Data showed that the‐dental pulp of both young human and monkey teeth can recuperate from a state of suppurative inflammatory involvement. Healing occurred irrespective of whether the bacterial challenge was removed or left in place. Findings also indicated that an acute inflammatory lesion rapidly could result in total pulp tissue necrosis.

Lipopolysaccharides (LPS) from Bacteroides oralis and Veillonella parvula and cell wall material from Lactobacillus casei were studied for their capacity to induce leukocyte migration in the dental pulp and in an implanted wound chamber. Three adult monkeys were challenged using lyophilized material sealed into buccal Class V cavities prepared in dentin. Pulp tissue responses were observed histologically eight and 72 hours after initiation of the experiment. Subjacent to cut dentinal tubules, bacterial materials induced polymorphonuclear leukocyte (PMN's) infiltration in the pulp tissue of the majority of test teeth examined. Responses were similar for the three bacterial test materials at both time periods. Topical applications of bovine serum albumin (BSA), used as a control, induced significantly less accumulation of PMN's. Assessments of induced exudate volumes and leukocyte densities in chambers implanted in rats showed comparable rankings with pulpal experiment between test (i.e., bacterial) and control (BSA) materials. Analysis of the data indicates that high-molecular-weight complexes of bacterial cell walls may adversely affect pulpal tissue across freshly exposed dentin.

Intraalveolar transplantation of teeth with unfavourable cervical root fractures were performed in 15 patients. The roots were surgically extruded on an average 4.5 mm, and autologous bone transplants were placed above the apical part to support the root. Temporary endodontic therapy was carried out before the transplantation in 10 patients and 3 weeks after transplantation in 2 patients. 3 of the teeth had old root fillings. Postoperative controls were made weekly during the first month, after 3 months, 6 months, 1 and 2 years. The roots had become stable in most cases after 3 weeks. The mobility grade was dependent on the extent of extrusion. Radiographic controls showed formation of a normal periodontal space around the roots after 3 months, but also minor root resorption in the most apical part in 10 of the cases. The resorption was, however, not progressive in nature and was limited to the apical part. Remodelling of the marginal bone contour around the transplanted roots was evident in 11 patients. Periapical destructions were found in 3 patients at the 2-year control. Crown therapy was carried out with due attention to the special prosthetic problems associated with preparation of small remaining root fragments with unfavourable crown/root ratio.

Cell material from three different dental plaque bacteria (Actinomyces viscosus, Streptococcus mitis, Actinobacillus actinomycetemcomitans) were studied for their capacity to induce leukocyte migration in the dental pulp of monkeys. Altogether five animals were used to provide 123 teeth for the study. The bacterial test materials were prepared from lyophilized sonicates of pure cultures of respective bacteria mixed with crystalline bovine serum albumin (BSA) 1:1 by weight. Immediately prior to use in the experiment saline was added to render the test material into a paste-like consistency. Buccal Class V cavities were prepared in the monkey teeth leaving a thin remaining wall to the pulp. In these cavities, the test materials were enclosed for a period of 8 h. A set of control cavities received BSA alone. Placement of test and control materials were made before and after depleting the animals of serum complement by repeated injections of Cobra Venom Factor. Histologic examination of pulp tissue specimens showed that materials from two of the bacterial species (A. viscosus, Act. actinomycetemcomitans) consistently induced infiltrations of polymorphonuclear leukocytes in one to several cell layers underneath the test cavity. The material from S. mitis seemed less potent and in 11 of 22 teeth no pulpal reaction was recorded. Inactivation of complement with Cobra Venom Factor did not appear to affect the severity of the pulpal responses.

Intraalveolar transplantation of teeth with unfavourable cervical root fractures were performed in 15 patients. The roots were surgically extruded on an average 4.5 mm, and autologous bone transplants were placed above the apical part to support the root. Temporary endodontic therapy was carried out before the transplantation in 10 patients and 3 weeks after transplantation in 2 patients. 3 of the teeth had old root fillings. Postoperative controls were made weekly during the first month, after 3 months, 6 months, 1 and 2 years. The roots had become stable in most cases after 3 weeks. The mobility grade was dependent on the extent of extrusion. Radiographic controls showed formation of a normal periodontal space around the roots after 3 months, but also minor root resorption in the most apical part in 10 of the cases. The resorption was, however, not progressive in nature and was limited to the apical part. Remodelling of the marginal bone contour around the transplanted roots was evident in 11 patients. Periapical destructions were found in 3 patients at the 2-year control. Crown therapy was carried out with due attention to the special prosthetic problems associated with preparation of small remaining root fragments with unfavourable crown/root ratio.

SummaryThe EMG activity in the temporal muscle, masseter muscle, and in the lower lip was recorded during 27 minutes use of three makes of mouth‐pieces for air supply during diving. For comparison, recordings were made also of the muscle activity with the mandible in the postural position and during maximal bite. Five male amateur divers, aged 22–35, took part in the investigation.The muscle activity necessary to hold the mouthpiece in position varied from one make of mouthpiece to the other. Compared with the activity with the mandible in the postural position, the activity in the lip increased most, and then considerably, during use of a mouthpiece. Two of the mouthpieces also raised the activity in the masseter muscle. The temporal muscle was affected least and showed an increase in activity during use of only one of the mouthpieces.In the laboratory experiments the muscle activity necessary for retention of the mouthpieces was only a fraction of that during maximal bite. It is stressed, however, that the force with which the mouthpiece is gripped when diving may, owing to emotional factors, be much greater. To avoid undue muscle fatigue and pain it is therefore recommended to use the mouthpiece which, according to the laboratory studies, was shown to require the least muscle activity for retention.