Influence of several root canal disinfection methods on pushout bond strength of self-etch post and core systems.

AIM: To determine the effect of four root canal disinfection protocols (2.5% sodium hypochlorite, 0.2% chlorhexidine gluconate, gaseous ozone and Nd : YAG laser) on the pushout bond strength of a self-etch post and core system. METHODOLOGY: Sixty anterior single-rooted permanent human teeth were used. Root canals were instrumented with ProTaper instruments (Dentsply Maillefer; Ballaigues, Switzerland). Roots were divided into four groups (n = 15 each) according to the final disinfection protocol: sodium hypochlorite, chlorhexidine gluconate, gaseous ozone and Nd:YAG laser. Fibre-reinforced composite post preparations were created in previously filled root canals, and posts cemented according to the manufacturer's instructions. Roots were then uniformly sectioned and prepared for the pushout bond strength testing in a universal testing machine. One-way anova with post hoc Scheffe test was used for statistical analysis. SEM imaging of one sample from each group was made. RESULTS: The only significant difference (P = 0.004) was observed between sodium hypochlorite irrigation, which was associated with the lowest bond strength, and Nd:YAG laser irradiation, which provided the highest bond strength. There was no difference between root canal pre-treatment with sodium hypochlorite, gaseous ozone and chlorhexidine, nor between gaseous ozone, chlorhexidine and Nd : YAG laser. CONCLUSION: Sodium hypochlorite irrigation was associated with the lowest bond strength values and Nd : YAG laser irradiation with the highest bond strength values for a self-etch post and core system bonded to root canal dentine.

Treatment of invasive cervical resorption with sandwich technique using mineral trioxide aggregate: a case report.

This article presents two cases of large invasive cervical resorption (ICR) with maintenance of pulp vitality after treatment with mineral trioxide aggregate (MTA) in a sandwich technique.Invasive cervical resorption is a relatively uncommon but aggressive form of external resorption, primarily caused by dental trauma or injury of the cervical periodontal attachment. The resorptive process does not penetrate into the root canal, and the pulp is not involved in the first phase of the resorption. This feature differentiates external resorption from internal resorption. In most cases, invasive cervical resorption is found during routine radiographic or clinical examination. Different materials have been proposed for the treatment of external cervical resorption. Therapy can be effective when it 1) removes the etiological factors and 2) interrupts the progressive resorption mechanism.The key learning points of this article are the following: treatment strategy to arrest the cervical resorption process and to prevent further resorption without changing pulpal vitality and successful seal of invasive cervical resorption defect using MTA with a sandwich technique.

An analysis of 58 traumatically intruded and surgically extruded permanent teeth.

Fifty-eight traumatically intruded and mainly surgically extruded permanent teeth were followed up for 3 years and 4 months (mid-term results: 29 teeth) and 9 months (short-term results: 29 teeth) on average. Statistically, the mid-term results showed more cases of severe crown discoloration (54%) than the short-term results (9%), but no difference in pulpal and periodontal healing. Three teeth (5%) were lost. Factors which positively influenced pulpal healing were shallow intrusion depth, intact crown and immaturity of the root. Factors which positively influenced periodontal healing were shallow intrusion depth and minimal surgical manipulation. Alveolar bone healing was positively influenced only by shallow intrusion depth.

Five-year follow-up of internal bleaching.

A 5-year clinical follow-up study was conducted to determine the longevity of originally acceptable results for internal bleaching. The "walking internal bleaching" method is an acceptable technique of lightening discolored anterior teeth to provide an esthetically pleasing match with adjacent teeth. This follow-up study revealed a success rate of 79% for all indications after 5 years. If the indication is limited to one palatal endodontic opening, the total success rate can reach 91%. However, a 98% success rate is common when subjective evaluation of patients is considered. The results clearly indicated that internal bleaching provides long-term success for treatment of discolored nonvital anterior teeth over a period of years and does not have any detrimental effect on dental hard tissue. In ideal cases, if the procedure is performed precisely, the success rate can exceed 90% after five years.

Intrapulpal temperature during preparation with the Er:YAG laser compared to the conventional burr: an in vitro study.

OBJECTIVE: The authors explored whether the preparation with the Er:YAG laser showed a difference in increase of intrapulpal temperature in comparison to the conventional burr. SUMMARY BACKGROUND DATA: The effect of preparation with the Er:YAG laser on the temperature in the pulp is probably the biggest problem in using the laser for preparation of dental hard tissue. METHODS: The effect on the temperature in the pulp was studied on extracted human incisors and canines in vitro in palatinal class I cavities. The temperature during preparation with the Er:YAG laser was compared to that recorded during conventional tactile preparation with a diamond burr. The study was designed so that the pulpal cavity and the measuring probe were kept at a constant temperature of 37 degrees C from the root upward while the crown, which was thermally isolated, was exposed to preparation and cooling agents. RESULTS: During preparation with the laser, there was a temperature drop after a few seconds from 37 degrees C to 25 degrees C to 30 degrees C due to cooling with water and air. Even with trepanation, there was only an increase in temperature in the pulp when the temperature measuring probe was hit directly by the laser beam. With conventional preparation in comparison, even before trepanation there was a rise in temperature to more than 60 degrees C. CONCLUSIONS: The reduction in pain with clinical use of the Er:YAG laser for class V cavities has already been mentioned in publications and could, in addition to the nontactile preparation, be due to the lesser increase in intrapulpal temperature during the laser preparation in comparison to the conventional burr.

A study of replanted permanent teeth in different age groups.

The purpose of this study was to evaluate the benefits of replanting avulsed permanent teeth in different age groups. Of the 112 replanted teeth, 103 could be examined after 2.5 years on average. The teeth were divided into three groups: immature teeth (group A), mature teeth in children and adolescents (group B), and mature teeth in adults (group C). Concomitant injuries did not differ statistically between the groups. Extra-alveolar time with unphysiologic storage was longer than 15 min in 81 teeth. The results were statistically different for pulpal healing (A >> B > C), loss of marginal bone (C > A), amount of replacement resorption (A and B > C), alveolar growth inhibition (A > B >> C), local gingivitis (B > A and C) and buccal gingival retraction (C > A and B). Only 3 of 23 extracted teeth were lost because of replacement resorption alone. Only 2 of the 23 extracted teeth showed revascularization of the pulp. The results suggested that replanting avulsed teeth should be considered a temporary solution in children and adolescents. In these patients, the benefit of tooth replantation is mainly the time gained to establish an optimal treatment plan. Mature teeth with a necrotic periodontal ligament replanted in children before the pubertal growth spurt seemed to have the poorest prognosis.

[Replantation of avulsed immature permanent teeth. Results in 39 cases after an average of 2.5 years]. / Replantation totalluxierter unreifer bleibender Zähne. Durchschnittliche 2,5-Jahres-Ergebnisse in 39 Fällen.

The aim of this investigation was a critical assessment of the short- and medium-term results of replantation of immature, avulsed permanent teeth. Thirty-nine teeth were investigated after 2.5 years on average. Only 7 teeth (18%) had been replanted within 5 min after avulsion. Sixteen teeth (41%) showed revascularisation or ingrowth of alveolar bone into the pulp. Twenty-two teeth (56%) showed signs of ankylosis, 6 (15%) had been exfoliated or extracted. Seventeen teeth (77% of the ankylotic ones) exhibited an alveolar growth arrest of 1.5 mm per 10 cm body growth. By planimetric assessment, the yearly loss of root dentin by replacement resorption was about 15%. The appearance was compromised in 11 cases (33%) by severe discoloration. In spite of intense therapeutic effort and partial success, the results must be classified as unsatisfactory. In avulsions of immature permanent teeth, replantation therefore has to be considered an intermediate solution. Since the main reason for a failure is extended extra-oral unphysiologic storage, replantation by lay helpers immediately after the accident should be propagated as a first-aid treatment to improve the situation of the replanted tooth. In addition, more attention should be paid to preserving teeth in tissue cultures before replantation.

Splints made of wire and composite: an investigation of lateral tooth mobility in vivo.

In 103 posttraumatic splints, later tooth mobility was measured with Periotest immediately before and after the routine splint removal. The splints were made of composite resin and an 0.017 X 0.025" orthodontic steel wire. 481 teeth were measured. A statistic evaluation revealed that the immobilisation effect did not exceed normal tooth firmness. Fixation to one neighbouring tooth had less effect than fixation to two. Adjacent tooth gaps reduced the effect. Splint extensions had no influence. With the use of the Periotest device, more than 50% of all teeth with a true mobility of 20 Periotest-units or more were detectable as mobile in spite of the fixed splint.

[Caries prevalence, periodontal status, traumatised anterior teeth and sealant in 11-14-year olds in Styria]. / Kariesprävalenz, Parodontalzustand, Frontzahntrauma und Versiegelungen bei 11- und 14jährigen der Steiermark.

The average caries prevalence for first year pupils in secondary schools (Hauptschulen and Gymnasien) was 3.2 DMFT and 5.8 DMFS. The corresponding values for fourth year pupils were 6.4 DMFT and 12.4 DMFS. The proportion of children with at least one extracted first molar was 9.2%. Significant differences were observed between the two schooltypes. The periodontal assessment showed pocket depth greater than 3 mm in at least one molar in 42% of the fourth year children. Only 3-4% of those examined had sealed fissures. Carles prevalence in Styrian children is considerably higher than reported for other countries. It therefore appears necessary to intensify dental health in this age group.