Meta-analysis of the influence of bonding parameters on the clinical outcome of tooth-colored cervical restorations

PURPOSE: To meta-analyze the literature on the clinical performance of Class V restorations to assess the factors that influence retention, marginal integrity, and marginal discoloration of cervical lesions restored with composite resins, glass-ionomer-cement-based materials [glass-ionomer cement (GIC) and resin-modified glass ionomers (RMGICs)], and polyacid-modified resin composites (PMRC). MATERIALS AND METHODS: The English literature was searched (MEDLINE and SCOPUS) for prospective clinical trials on cervical restorations with an observation period of at least 18 months. The studies had to report about retention, marginal discoloration, marginal integrity, and marginal caries and include a description of the operative technique (beveling of enamel, roughening of dentin, type of isolation). Eighty-one studies involving 185 experiments for 47 adhesives matched the inclusion criteria. The statistical analysis was carried out by using the following linear mixed model: log (-log (Y /100)) = β + α log(T ) + error with β = log(λ), where β is a summary measure of the non-linear deterioration occurring in each experiment, including a random study effect. RESULTS: On average, 12.3% of the cervical restorations were lost, 27.9% exhibited marginal discoloration, and 34.6% exhibited deterioration of marginal integrity after 5 years. The calculation of the clinical index was 17.4% of failures after 5 years and 32.3% after 8 years. A higher variability was found for retention loss and marginal discoloration. Hardly any secondary caries lesions were detected, even in the experiments with a follow-up time longer than 8 years. Restorations placed using rubber-dam in teeth whose dentin was roughened showed a statistically significantly higher retention rate than those placed in teeth with unprepared dentin or without rubber-dam (p < 0.05). However, enamel beveling had no influence on any of the examined variables. Significant differences were found between pairs of adhesive systems and also between pairs of classes of adhesive systems. One-step self-etching had a significantly worse clinically index than two-step self-etching and three-step etch-and-rinse (p = 0.026 and p = 0.002, respectively). CONCLUSION: The clinical performance is significantly influenced by the type of adhesive system and/or the adhesive class to which the system belongs. Whether the dentin/enamel is roughened or not and whether rubberdam isolation is used or not also significantly influenced the clinical performance. Composite resin restorations placed with two-step self-etching and three-step etch-and-rinse adhesive systems should be preferred over onestep self-etching adhesive systems, GIC-based materials, and PMRCs.

Replacement of Hopeless Retained Primary Teeth by Immediate Dental Implants: A Case Report

Hopeless retained primary teeth without permanent successors represent a restorative challenge for clinicians, along with esthetic and functional problems for patients. While various treatment approaches for congenitally missing teeth have been proposed, the replacement of a missing tooth with a dental implant offers specific advantages, such as preservation of the alveolar crest and elimination of the need to restore the adjacent teeth, over other options for tooth replacement. The aim of this article was to illustrate the surgical and prosthetic treatment with implants of a patient with primary teeth without permanent successors. INT J ORAL MAXILLOFAC IMPLANTS 2009;24:151-154

Microbial culture and checkerboard DNA-DNA hybridization assessment of bacteria in root canals of primary teeth pre- and post-endodontic therapy with a calcium hydroxide/chlorhexidine paste

Aim. To investigate the root canal microbiota of primary teeth with apical periodontitis and the in vivo antimicrobial effects of a calcium hydroxide/chlorhexidine paste used as root canal dressing. Design. Baseline samples were collected from 30 root canals of primary teeth with apical periodontitis. Then, the root canals were filled with a calcium hydroxide paste containing 1% chlorhexidine for 14 days and the second bacteriologic samples were taken prior to root canal filling. Samples were submitted to microbiologic culture procedure to detect root canal bacteria and processed for checkerboard DNA-DNA hybridization. Results. Baseline microbial culture revealed high prevalence and cfu number of anaerobic, black-pigmented bacteroides, Streptococcus, and aerobic microorganisms. Following root canal dressing, the overall number of cfu was dramatically diminished compared to initial contamination (P < 0.05), although prevalence did not change (P > 0.05). Of 35 probes used for checkerboard DNA-DNA hybridization, 31 (88.57%) were present at baseline, and following root canal dressing, the number of positive probes reduced to 13 (37.14%). Similarly, the number of bacterial cells diminished folowing application of calcium hydroxide/chlorhexidine root canal dressing (P = 0.006). Conclusion. Apical periodontitis is caused by a polymicrobial infection, and a calcium hydroxide/chlorhexidine paste is effective in reducing the number of bacteria inside root canals when applied as a root canal dressing.

Arrest of root formation in a permanent maxillary central incisor subsequent to trauma and pulp necrosis to the primary predecessor

This paper reports a case in which a previous traumatic injury at the age of 2 and pulp necrosis to a primary incisor resulted in a rare injury to the permanent successor tooth. The radiographic examination at the age of 9 showed the arrest of root formation of the permanent maxillary right central incisor, which did not erupt. Tooth 11 was extracted and a functional removable space maintainer was prepared. At the age of 17, the patient received an anterior fixed prosthesis for re-establishment of the esthetics, phonetics and deglutition.

Ex vivo evaluation of the accuracy of two electronic apex locators during root canal length determination in primary teeth

Aim To evaluate ex vivo the accuracy of two electronic apex locators during root canal length determination in primary incisor and molar teeth with different stages of physiological root resorption. Methodology One calibrated examiner determined the root canal length in 17 primary incisors and 16 primary molars (total of 57 root canals) with different stages of root resorption based on the actual canal length and using two electronic apex locators. Root canal length was measured both visually, with the placement of a K-file 1 mm short of the apical foramen or the apical resorption bevel, and electronically using two electronic apex locators (Root ZX II - J. Morita Corp. and Mini Apex Locator - SybronEndo) according to the manufacturers` instructions. Data were analysed statistically using the intraclass correlation (ICC) test. Results Comparison of the actual root canal length and the electronic root canal length measurements revealed high correlation (ICC = 0.99), regardless of the tooth type (single-rooted and multi-rooted teeth) or the presence/absence of physiological root resorption. Conclusions Root ZX II and Mini Apex Locator proved useful and accurate for apex foramen location during root canal length measurement in primary incisors and molars.

Effect of different bleaching systems on the ultrastructure of bovine dentin

The aim of this study was to evaluate in vitro the effect of different in-office bleaching systems on the surface morphology of bovine dentin. Thirty tooth fragments measuring 4 x 4mm, containing enamel and dentin, were obtained from the crowns of extracted bovine incisors. Samples were subjected to simulated intracoronal bleaching techniques using conventional (Opalescence Endo (R) and Whiteness Super Endo (R)) and light-activated systems (Opalescence Xtra (R) and Whiteness HP Maxx (R)). Controls were treated with either sodium perborate mixed with 10% hydrogen peroxide or no bleaching agent. The samples were observed under SEM and the recorded images were evaluated for topographic alterations. The ultrastructural alterations of dentin observed in this study varied greatly between groups according to the products used. Higher pH products (Whiteness HP Maxx (R) and Opalescence Xtra (R)) associated with in-office techniques yielded better maintenance of dentin ultrastructure. Apparently, both low pH and hydrogen peroxide oxidation play a role in altering the ultrastructure of dentin during internal dental bleaching. The use of alkaline products with reduced time of application (in-office techniques) may decrease such morphological alterations.

In vitro analysis of human tooth pulp chamber temperature after low-intensity laser therapy at different power outputs

In vitro studies have provided conflicting evidence of temperature changes in the tooth pulp chamber after low-level laser irradiation of the tooth surface. The present study was an in vitro evaluation of temperature increases in the human tooth pulp chamber after diode laser irradiation (GaAlAs, lambda = 808 nm) using different power densities. Twelve human teeth (three incisors, three canines, three premolars and three molars) were sectioned in the cervical third of the root and enlarged for the introduction of a thermocouple into the pulp chamber. The teeth were irradiated with 417 mW, 207 mW and 78 mW power outputs for 30 s on the vestibular surface approximately 2 mm from the cervical line of the crown. The highest average increase in temperature (5.6A degrees C) was observed in incisors irradiated with 417 mW. None of the teeth (incisors, canines, premolars or molars) irradiated with 207 mW showed temperature increases higher than 5.5A degrees C that could potentially be harmful to pulp tissue. Teeth irradiated with 78 mW showed lower temperature increases. The study showed that diode laser irradiation with a wavelength of 808 nm at 417 mW power output increased the pulp chamber temperature of certain groups of teeth, especially incisors and premolars, to critical threshold values for the dental pulp (5.5A degrees C). Thus, this study serves as a warning to clinicians that ""more"" is not necessarily ""better"".

Dentin hypersensitivity clinical study comparing LILT and LEDT keeping the same irradiation parameters

Dentin hypersensitivity is a common condition associated with high dental pain. A new LED-based (light emitting diode) light source has been used as an experimental tool in some studies. Purpose: The main objective was to compare these two light sources emitting in the same spectral band (red from 625 to 660 nm) to promote pain relief. Material and methods: A total of 6 sessions were accomplished, being three irradiation sessions and three follow-up sessions. This single-blind study compared a control group (Placebo) and two other groups with different equipments: low laser intensity treatment (LILT) and a light emitting diode system treatment (LEDT). Results: The results showed that there is no statistical difference between LILT and LEDT groups, however, both were better than control group (p=0.01) in terms of treatment efficiency; there is no difference between the second and the third sessions for both treatment, it means that the third session was not necessary; finally, the improvement at the end of the entire research (follow up care of 30 days) was very expressive in comparison to pre-treatment situation for all teeth (p=0.01). Conclusion: LILT and LEDT were equally effective to treat dentine hypersensitivity, a 3rd treatment session was not necessary/two sessions are enough.

Análise da dentina de dentes decíduos submetidos ao capeamento pulpar indireto

O objetivo do estudo foi avaliar as características da dentina cariada remanescente de molares decíduos quanto à coloração, consistência e microdureza, após um período médio de 3 anos e 8 meses da realização do capeamento pulpar indireto. O estudo clínico constou de 27 dentes que apresentavam lesões cariosas ativas com expressão radiográfica em metade interna de dentina. Aleatoriamente, foi realizado o capeamento pulpar indireto e utilizado como material capeador o hidróxido de cálcio (HC) e o cimento de ionômero de vidro resinoso modificado (CIVRM). As crianças foram acompanhadas através de exames clínicos e radiográficos, e ao longo de um período médio de 3 anos e 8 meses, observou-se um índice de sucesso de 89% para o grupo do HC e de 93% para o CIVRM, não havendo diferença estatisticamente significante entre os dois grupos (p=0,62). Os dentes considerados como sucesso no estudo clínico foram agrupados em um único grupo (grupo teste), que constou de 13 dentes que sofreram esfoliação natural ou exodontia por motivos ortodônticos. Além disso, foram selecionados 15 molares decíduos hígidos (grupo controle positivo) e 15, portadores de lesões cariosas ativas em metade interna de dentina (grupo controle negativo). As amostras do grupo teste tiveram suas respectivas restaurações removidas, a profundidade medida e a dentina remanescente avaliada por um operador calibrado, seguindo critérios descritivos, quanto à consistência e a coloração. Nos dentes do grupo controle positivo, foram realizados preparos cavitários oclusais em até 4 mm de profundidade, enquanto que, no grupo controle negativo, o mesmo operador do estudo clínico realizou a remoção parcial de tecido cariado in vitro. A partir daí, todos os dentes foram preparados para análise de microdureza, que foi realizada por um examinador calibrado, que empregou o princípio de cegamento. Na análise da consistência, todos os dentes do grupo teste (n=13) apresentaram-se endurecidos, enquanto que 9, apresentaram coloração amarela-clara (8 do CIVRM e 1 do HC) e 4, castanho-escura (1 do CIVRM e 3 do HC). Para o teste de microdureza no grupo teste, obteve-se uma média KHN de 40,81 (±16,28) MPa, enquanto que nos grupos controles positivo e negativo, foram alcançados valores médios de 62,73 (±11,24) MPa e 19,15 (±6,99) MPa, respectivamente. A análise estatística mediante o teste ANOVA indicou que houve diferença significativa entre os 3 grupos. Foi constatada a remineralização da dentina de dentes decíduos em que foi realizada a técnica do capeamento pulpar indireto após um período médio de 3 anos e 8 meses, através de critérios clínico (consistência) e laboratorial (análise da microdureza).

Evaluation of sixth grade primary schoolchildren's knowledge about avulsion and dental reimplantation

Dental trauma, particularly tooth avulsion, is a frequent cause of tooth loss in children, adolescents, and young adults. The avulsed tooth should be immediately reimplanted in its alveolus. This procedure can be performed by anyone at the accident site and not only by dental surgeons. Therefore, the purpose of this study is to evaluate the knowledge of sixth graders of the city of Aracatuba, SP, about dental avulsion and tooth reimplantation through a structured and standardized survey. Our sample consisted of 778 students. The data collected was processed using the program epiinfo 2000. Most students were around 12 years of age and 94.5% related to practice some kind of sports. Results demonstrated that the possibility of tooth reimplantation after dental avulsion is not acknowledged among these students and dental traumatism was associated to caries, toothache, and use of orthodontic appliances. Only 18.9% of the students associated dental traumatism to an impact trauma; 3.6% would store the tooth in milk, and 3.1% believed the tooth could be reimplanted by anyone present at the accident site. In summary, the results show an overall the lack of knowledge about dental traumatism and highlight the need of special programs designed to educate school-aged students about emergency procedures to handle cases of dental traumatisms.

Occurrence of tooth injuries in patients treated in hospital environment in the region of Aracatuba, Brazil during a 6-year period

Dental trauma has been considered as a public health problem that affects mainly children and youngsters and due to its impact on the patient's quality of life. This study presents the results of a 6-year survey of the occurrence and characteristics of dental trauma in patients admitted to the Service of Surgery and Oral and Maxillofacial Traumatology of the School of Dentistry of Aracatuba (UNESP, Brazil) after emergency care in hospital facilities in the region of Aracatuba, SP, Brazil. For such purpose, the clinical files of patients treated at the Service between 1999 and 2005 were reviewed. Information regarding gender, age, number of traumatized teeth, etiology and diagnosis of the trauma was collected from the files of patients with tooth injuries and recorded in case report forms specifically designed for this purpose. The results showed that from a total of 4112 patients admitted to the Service within the surveyed period, 266 (6.5%) had tooth injuries (172 males - 64.7%; 94 females - 35.3%). The total number of traumatized teeth was 496. Most patients belonged to the 16-20 year-old age group (20.3%) and the most frequent causes of tooth injuries were bicycle accidents (28.6%), motorcycle accidents (19.2%) and falls (18.8%). Injuries to the periodontal tissues were the most frequent type of tooth injuries (408 teeth; 82.26%), occurring in 118 primary and 290 permanent teeth. Among the injuries to the periodontal tissues, avulsion was the most common (32.86%) (29.41% for primary and 34.0% for permanent teeth), followed by extrusive luxation (19.15%) (25.21% for primary and 17.24% for permanent teeth). In conclusion, in the surveyed population, cases of tooth injuries were more frequent in males aged 16-20 years old due to cyclist accidents with predominance of injuries to the periodontal tissues, in particular, avulsions.

A combination of clinical and microbiological management of generalized aggressive periodontitis in primary teeth. A case report

International Journal of Paediatric Dentistry 2012; 22: 310316 Background. Generalized aggressive periodontitis (GAP) in primary teeth is a rare periodontal disease that occurs during or soon after eruption of the primary teeth. An association with systemic diseases is a possibility. Case Report. A 4-year-old Brazilian girl presented with GAP involving the entire primary dentition. The patient and her parents and sister were subjected to microbiological testing to identify the microorganisms involved in the disease. The patient underwent tooth extraction to eradicate the disease and received a prosthesis for the restoration of masticatory function. After the permanent teeth erupted, fixed orthodontic appliances were place to restore dental arch form and occlusion. Conclusions. The results show the importance of an early diagnosis of GAP and of a multidisciplinary approach involving laboratory and clinical management to treat the disease and to restore masticatory function, providing a better quality of life for patients.

Luxation injuries in primary teeth: a retrospective study in children assisted at an emergency service

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Immediate reimplantation of primary teeth: a histological study in dogs

Reimplantation of primary teeth has been the subject of various clinical and histological studies, but very little is known about the effect of this treatment on primary teeth. The aim of the present study was to histologically evaluate the biological response of dog primary teeth after immediate reimplantation. Twelve dogs were divided into two groups according to postoperative time: 1 week and 3 weeks. Twenty-one upper and lower intermediate incisors were extracted and submitted to endodontic treatment, reimplantation and splinting. The 21 homologous teeth not submitted to treatment served as controls. The animals were killed after the respective experimental periods, and the obtained specimens were processed for histological analysis. Most dogs of the 1-week group exhibited the following alterations: gingival epithelium was inserted in the cemento-enamel junction, with a small number of chronic inflammatory cells being observed in the gingival corium; the periodontal ligament was partially reestablished, with a more expressive chronic inflammatory infiltrate being observed in the apical third; small root resorption was observed on the palatine/lingual side in the apical third. In contrast, in 3-week animals, gingival epithelial insertion was predominantly absent on the buccal side, and a moderate chronic inflammatory infiltrate was present; the periodontal ligament generally showed no bone-cementum reinsertion especially on the palatine/lingual side, with an expressive inflammatory infiltrate in the apical region, and large root resorption was mainly observed on the palatine and lingual sides. In conclusion, reimplantation causes histological alterations in the tooth and its supporting periodontal structures that suggest the impossibility of its maintenance.

Chlorhexidine increases the longevity of in vivo resin-dentin bonds

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)