Probiotics affect the clinical inflammatory parameters of experimental gingivitis in humans.

OBJECTIVES: To determine the effects of a probiotic milk drink consumed over a period of 28 days, regarding the expression of clinical inflammatory parameters of the oral gingiva during various phases of plaque-induced gingivitis. METHODS: Twenty-eight adults with healthy gingiva took part in a prospective and clinical-controlled study. The test group was advised to consume a probiotic milk drink (Yacult) daily during a period of 4 weeks; the control group did not receive any probiotic food or drink. After 2 weeks of consumption of the probiotic drink, participants were advised not to brush their teeth for 14 days. Subsequently, at baseline as well as on days 1, 3, 5, 7 and 14, the following clinical parameters were assessed: plaque index (PI), gingival index (GI), gingival crevicular fluid (GCF) volume and bleeding on probing (BOP). RESULTS: At baseline, the PI was significantly higher in the test group compared with controls (0.44±0.50 vs 0.09±0.24 PI; P=0.0001). The termination of oral hygiene increased clinical inflammatory parameters in both groups. At day 14, the parameters PI, GI, GCF volume and BOP were significantly higher compared with baseline values (P=0.0001). At day 14, BOP levels (18.75±12.32 vs 36.88±12.54%) and GCF volume (18.78±16.7 vs 35.72±16.1 Periotron units) were significantly lower in the test group compared with the control group (P=0.005). CONCLUSION: The results of our study indicate that a daily consumption of a probiotic milk drink reduces the effects of plaque-induced gingival inflammation associated with a higher plaque score due to the high-carbohydrate content of the probiotic milk beverage.

Autotransplantation of immature third molars into edentulous and atrophied jaw sections.

The aim of the present study was to assess the results after transplantation of 85 immature third molars. Recipient site conditions varied and different surgical techniques were used. The long-term results after preparation of a new alveolus, splitting osteotomy of the alveolar process or use of free bone autografts were compared with the results after transplantation into a fresh extraction site (control group). Transplantations into prepared sockets showed equal results to the control group (94% respectively). Transplantations in connection with free bone autografts (84%) or after splitting osteotomy of the alveolar process (63%) showed poorer success rates, the differences between the latter and the control group being statistically significant. A possible correlation to revascularization disturbances of the pulp due to an insufficiency of the recipient site or to postoperative infection is suspected. The results show that transplantation of immature third molars is a safe, useful procedure when appropriate conditions of the recipient site are present. Where the alveolus is atrophic, a splitting osteotomy should be performed only in exceptional cases and preference should be given to alternative methods such as primary bone augmentation or bone-regenerative procedures.

Comparison of the number and diameter of dentinal tubules in human and bovine dentine by scanning electron microscopic investigation.

Detailed information on dentine structure is essential for interpreting data from investigations on dentine-adhesive materials. The purpose here was to compare the number and diameter of dentinal tubules at similarly prepared surfaces of bovine permanent central incisors and human deciduous and third molars. In bovine teeth, crowns and roots were used; in human samples only the crowns were investigated. Tubule density in the middle layer was higher in bovine root (BR) dentine (number of tubules per mm(2)+/-SD: 23, 760+/-2453) than in human deciduous (HD) (18,243+/-3845), human permanent (HP) (18,781+/-5855), and bovine coronal (BC) (17, 310+/-2140) dentine. The corresponding values for the deep layer were 23,738+/-4457 (BR), 24,162+/-5338 (HD), 21,343+/-7290 (HP), and 20,980+/-4198 (BC). No significant differences were found for the number of dentinal tubules in bovine coronal dentine compared to the dentine of human deciduous and permanent molars. The mean diameter of bovine dentinal tubules was slightly, but not significantly, higher than in human dentine (middle layer/deep layer+/-SD): BC, 2. 85 microm+/-0.18/3.50 microm+/-0.33; BR, 3.10 microm+/-0.33/3.23 microm+/-0.30; HD, 2.55 microm+/-0.16/2.82 microm+/-0.28; HP, 2.65 microm+/-0.19/2.90 microm+/-0.22. These findings demonstrate that corresponding coronal dentine layers of human deciduous and permanent molars, and of bovine central incisors, are not significantly different in their number of tubules per mm(2) and their tubule diameter, whereas tubule density in bovine root dentine is significantly higher. These results suggest that provided standardized preparations are used, bovine incisor crown dentine is a suitable substitute for human molar dentine in adhesion studies.

Transverse changes after surgical closure of complete cleft lip, alveolus and palate.

Surgery for patients with unilateral (UCLP) and bilateral (BCLP) complete cleft lip, alveolus and palate has a considerable influence upon craniofacial growth. With respect to this, the cleft team at Hannover Medical School has attempted to reduce necessary surgical interventions to labioplasty, palatoplasty and veloplasty. Still, the effects of these operations influence maxillary growth to an extent which requires orthodontic treatment in all patients. This study focuses upon the transverse alterations of the alveolar arch and the deciduous dentition after lip and palate surgery. Dental casts prior to any surgical intervention and after labioplasty and complete palaotoplasty of the hard and soft palate were measured for transverse changes by using anatomical landmarks. The results indicate a significant occurrence of anterior relative to posterior arch width loss for both UCLP and BCLP patients. Orthodontic treatment should be planned and performed with respect to these findings in order to support craniofacial growth and prevent maxillary dental arch deficiency.

Bovine dentin as a substitute for human dentin in shear bond strength measurements.

PURPOSE: To evaluate the suitability of bovine coronal and root dentin as substitutes for human primary and permanent dentin in shear bond strength tests for dentin adhesives. MATERIALS AND METHODS: 30 bovine permanent central incisors, 30 human primary and 30 human third molars were cut mesiodistally. The pulpal and buccal dentin surfaces of the buccal cuts were milled with a bur to a thickness of 1.0 mm. A dentin adhesive and a hybrid composite were applied exactly according to the instructions given by the manufacturer on each buccal and pulpal surface, except in primary teeth where only the buccal surface was used. Shear bond strength was determined after 24 hours of storage in an aqueous solution. The results were statistically analyzed using the Wilcoxon- or the Mann-Whitney-U-test. RESULTS: There were no differences in shear bond strengths between human permanent dentin and bovine coronal dentin (13.3 +/- 6.1 vs. 15.2 +/- 7.6), and between each pulpal and buccal aspect. Significant differences were found between bovine root dentin and human primary dentin (17.4 +/- 8.3 vs. 7.7 +/- 5.0, P < 0.001). Significant differences were also found between bovine root dentin and human permanent dentin (17.4 +/- 8.3 vs. 13.3 +/- 6.1, P < 0.05), and bovine root and coronal dentin (17.4 +/- 8.3 vs. 15.2 +/- 7.6, P < 0.05). Furthermore, significant differences were recorded between human primary and human permanent dentin (7.7 +/- 5.0 vs. 13.3 +/- 6.1, P < 0.001) and bovine coronal dentin (7.7 +/- 5.0 vs. 15.2 +/- 7.6, P < 0.001).

Erbium:YAG laser application in caries therapy. Evaluation of patient perception and acceptance.

OBJECTIVES: In previous studies it has been demonstrated that the Er:YAG laser can be used to prepare cavities efficiently and without thermal damage to the adjacent dental hard and soft tissues. To investigate the patients' response to Er:YAG laser preparation of teeth, a prospective clinical study was performed in five dental hospitals. METHODS: To evaluate patients' perception and response to cavity preparation a direct comparison was made between conventional mechanical preparation and Er:YAG laser preparation of caries in dental hard tissues. Half of the preparations were completed by the laser alone with standardized parameters, with the other half being mechanically prepared. The sequential order of treatment was randomized, and clinical parameters such as depth and location of the cavities were carefully balanced. A three-score evaluation scheme of patient responses was used: comfortable, uncomfortable, very uncomfortable. In addition the patients were asked to decide which was the more uncomfortable form of treatment and the preferred treatment for future caries therapy. RESULTS: The study included 103 patients with 206 preparations distributed amongst 194 teeth. All teeth gave vital responses (ice test) before and after both types of treatment. The laser treatment was found to be more comfortable than the mechanical treatment, with high statistical significance. During treatment, the need for local anaesthesia was 11% for mechanical preparation compared to 6% during laser application. It was found that 80% of the patients rated the conventional preparation as more uncomfortable than the laser treatment and 82% of the patients indicated that they would prefer the Er:YAG laser preparation for further caries treatment. CONCLUSIONS: The application of the Er:YAG laser system is a more comfortable alternative or adjunctive method to conventional mechanical cavity preparation.

Comparative studies of cardia carcinoma and infracardial gastric carcinoma.

In a part retrospective, part prospective study, 354 carcinomas of the cardia were compared with 1259 infracardial gastric carcinomas with regard to the age and sex of the patients, macroscopic classification, microscopic classifications, depth of invasion, and survival rates. Mortality rates are generally higher in cardia carcinoma than in stomach carcinoma. The difference is due to the significantly poorer survival of cardia carcinoma patients in stage I, while mortality rates in stages II, III, and IV of both types are approximately similar. Highly significant differences were also found with regard to sex ratio, incidence of macro- and microscopic subtypes, and invasive growth. The typical cardia carcinoma occurs preferentially in men, is mostly well-delineated, and is manifested as an ulcerated or polypoid, well-differentiated tumor of expansive growth, corresponding to Laurén's intestinal type. These results confirm the concepts of McPeak and Warren, MacDonald, and Siewert et al., that the carcinoma located in the cardia must be seen as a separate entity of gastric carcinoma.