Regenerative Endodontic Procedures: A Perspective from Stem Cell Niche Biology.

INTRODUCTION: Endodontics uses cell therapy strategies to treat pulpal and periapical diseases. During these therapies, surgeons aim to reconstruct the natural microenvironments that regulate the activity of dental stem cells. METHODS: We searched for more than 400 articles in PubMed using key words from regenerative endodontics and dental stem cell biology. In 268 articles, we reviewed what factors may influence histologic results after preclinical dental treatments that use regenerative endodontic procedures after pulpectomy. RESULTS: Several factors, such as the origin of stem cells, the biomimicry of scaffolds used, and the size of lesions, are considered to influence the histologic appearance of the regenerated pulp-dentin complex after treatments. Information is accumulating on transcription factors that generate the pulp-dentin complex and survival/trophic factors that would benefit niche recovery and histologic results. CONCLUSIONS: In this article, we discuss the noninterchangeability of stem cells, the influence of dentin-entrapped molecule release on pulp regeneration and survival of stem cells, and the need of positional markers to assess treatments histologically. The ex vivo amplification of appropriate dental stem cells, the search for scaffolds storing the molecular diversity entrapped in the dentin, and the use of positional transcription factors as histologic markers are necessary to improve future preclinical experiments.

Viruses in pulp and periapical inflammation: a review.

The presence of viruses in endodontic disease has been studied in the last decade. Their presence is associated with periapical radiolucency and with clinical findings, such as pain. The aim of this review is to analyze the scientific evidence currently published about viruses in pulp and periapical inflammation, and its possible clinical implications. A literature review was carried out using the Medline/Pubmed database. The search was performed, in English and Spanish, using the following keyword combinations: virus AND endodontic; virus AND periapical; virus AND pulpitis; herpesvirus AND periapical; papillomavirus AND periapical. We subsequently selected the most relevant studies, which complied with the search criterion. A total of 21 articles were included, of which 18 detected the present of viruses in the samples. In 3 of the studies, viral presence was not found in the samples studied. The Epstein-Barr virus was found in about 41 % of cases compared to controls, in which it was present in about 2 %. The main association between viruses and endodontic pathosis is between Cytomegalovirus and Epstein-Barr virus; these are found in 114 of the 406 samples of different endodontic pathosis. Some evidence supports that the Epstein-Barr virus is present in a significant number of endodontic diseases, without exact knowledge of their action in these diseases.

Virus en Endodoncia / Viruses in Endodontics

La infección endodóntica es la infección que afecta al sistema de conductos radiculares y, sin duda, es el principal agente etiológico de las periodontitis apicales. Además, de las bacterias patógenas endodónticas, se ha buscado en los últimos años asociar la presencia de virus en distintos tipos de patología endodóntica. Los virus que más se han buscado y asociado son los pertenecientes a la familia herpesvirus, los cuales se han encontrado presentes en patologías periapicales principalmente. Se ha buscado además, relacionar su presencia a patologías que cursan con mayor sintomatología, o que presentan a la imagen radiográfica destrucciones óseas periapicales mayores. El rol de los virus en las lesiones apicales de origen endodóntico está aún poco claro, se habla de efectos acumulativos a los de las bacterias, además de posibles inmunosupresiones locales que favorecerían el crecimiento y el efecto de estas últimas.

Endodontic infection is an infection of the root canal system and undoubtedly is the main etiological agent of apical periodontitis. In recent years, research has aimed to associate the presence of virus and endodontic bacterial pathogens in the different types of endodontic disease. The most common viruses that have been researched and associated are members of the herpesvirus family, which are mainly present in periapical pathologies. Furthermore, research has been carried out relating their presence to pathologies with important symptoms, or those where radiographic imaging shows extensive apical bone reabsorption. The role of viruses in apical lesions of endodontic origin are still unclear, it hypothesizes the cumulative effect with bacteria, in addition to possible local immunosuppression that favors the growth and the effect of bacteria.

Influence of state anxiety and trate anxiety in postoperative in oral surgery.

INTRODUCTION: The aim of this article was to study the influence of anxiety (both state and trait) in postoperative recovery after extraction of third molar together, to establish the role of each of the aspects of anxiety in the results you obtained in an independent and complementary way. MATERIAL AND METHOD: We performed a prospective study of a consecutive series of 88 patients who underwent lower third molar extractions. Before being provided with any information about the operation, patients were asked to complete the Spielberger State-Trait Anxiety Inventory- Trait and State. We have evaluated postoperative swelling and pain, patients completed a 10-point visual analog scale (VAS) at home each day (at approximately the same time of day as the operation) until day 8 after surgery, when the sutures were removed. RESULTS: Regarding postoperative variables between positive and negative trait anxiety groups, consumption of analgesic drugs was higher in positive trait anxiety group in a statistically significant way, while these differences were detected only on specific occasions regarding pain and swelling. DISCUSSION: In the present study, anxiety was taken into account and showed a significant effect in explaining postoperative pain and taking analgesics.

Management of perforating internal root resorption with periodontal surgery and mineral trioxide aggregate: a case report with 5-year follow-up.

Internal root resorption (IRR) is characterized by progressive loss of tooth substance initiating at the root canal wall as a result of clastic activity. The use of periodontal surgery and mineral trioxide aggregate is a good approach to repair lesions with periodontal communication (perforating IRR). This case describes the treatment and follow-up of a maxillary central incisor with perforating IRR in a 56-year-old male patient where root canal treatment, periodontal surgery, and white mineral trioxide aggregate were employed to achieve complete repair and to restore function. Clinical findings and periapical radiographs indicated success after a 5-year follow-up.

Evaluation of apical preparations performed with ultrasonic diamond and stainless steel tips at different intensities using a scanning electron microscope in endodontic surgery.

OBJECTIVE: The objective of our study is to analyse (with the help of scanning electron microscopes) the quality of the dental root surface and the appearance of dental cracks after performing apical preparations using two different types of ultrasonic tips. STUDY DESIGN: We used 32 single-rooted teeth that underwent a root canal and apical resection. Afterwards, the teeth were divided into 4 groups of 8 teeth each, with preparations of the apical cavities in the following manner: Group 1: stainless steel ultrasonic tip at 33 KHz. Group 2: stainless steel ultrasonic tip at 30 KHz. Group 3: diamond ultrasonic tip at 30 KHz. Group 4: diamond ultrasonic tip at 33 KHz. The quality of the root surface and the presence of cracks were evaluated by one single observer using a scanning electron microscope. RESULTS: All of the teeth in our study had cracks after the apical preparations. The mean number of cracks per tooth ranged between 6. ± 1.9 (group 1) and 3.5 ± 2.4 (group 4), with a significantly higher number found in the groups that used stainless steel tips (P=.03). The types of cracks produced involved: 8 complete cracks (4.5%), 167 incomplete cracks (94.4%), and 2 intradentinal cracks (1.1%), with no significant differences observed between the different frequencies used for each group. CONCLUSIONS: Stainless steel ultrasonic tips provoked a larger number of cracks than diamond tips. The frequency of vibration used did not have any effect on the number of cracks found.

Tobacco smoking and radiographic periapical status: a retrospective case-control study.

INTRODUCTION: The aim of this study was to investigate radiographically the relationship of tobacco smoking and periapical status by using a retrospective case-control study design. METHODS: The records of 79 controls and 79 age- and sex-matched cases were examined. Case was defined as a patient who has at least 1 radiographically detectable periapical lesion in a tooth. Control was defined as a patient who has no radiographically detectable periapical lesion in any teeth. Periapical status was assessed by using panoramic radiographs and the periapical index score. The history of smoking and diabetes, the number of teeth and root-filled teeth, and the quality of root fillings were recorded. Statistical analyses were conducted by using the Cohen kappa test, χ(2) test, Student's t test, and logistic regression analysis. RESULTS: Among the case subjects, 75% had antecedents of smoking, whereas in the control group only 13% had been smokers (odds ratio, 20.4; 95% confidence interval, 8.8-46.9; P = .0000). After multivariate logistic regression analysis adjusting for covariates (age, gender, number of teeth, root-filled teeth, root-filled teeth with a root filling technically unsatisfactory, and diabetes), a strong association was observed between the presence of at least 1 radiographically detectable periapical lesion and antecedents of smoking (odds ratio, 32.4; 95% confidence interval, 11.7-89.8; P = .0000). CONCLUSIONS: After adjusting for age, gender, number of teeth, endodontic status, quality of root filling, and diabetic status, tobacco smoking is strongly associated with the presence of radiographically diagnosed periapical lesions.

Suture needles in oral surgery: alterations depending on the type and number of sutures.

This study examined whether the number and type of sutures used in oral surgery influence two ad hoc variables (incision plane and displaced area), which are two variables related to whether the suture needle is suitable for the task. Seventy-five TB-15 needles were studied, which were used to suture between zero and three mucosa and/subperiosteal sutures, producing 15 groups with 5 needles in each one. The incision plane and displaced area were measured for each group, which are two variables related to how the needle has worn and altered. Statistical treatment was conducted using the Kruskal-Wallis H test to compare multiple values and the Mann-Whitney U test to compare pairs. A multi-stage regression model was applied with the aim of predicting the changes in the dependent variables based on the number and type of sutures performed. The incision plane ranged from 126.67 to 346.24 µm among the different groups. The displaced area was measured as being between 14 524.83 µm² and 128 311.91 µm². The best predictive model for the incision plane obtained a coefficient of determination (R2) of 0.149, while it reached 0.249 for the displaced area. Subperiosteal sutures held more weighting among the variables studied. Mucosal sutures did not seem to greatly affect needle wear. Observations reported in this paper indicate that the needle should be changed after having performed two subperiosteal sutures, given the wear and change to the incision plane that is produced, which causes the needle's cutting ability to reduce.

Relationship between smoking and endodontic variables in hypertensive patients.

INTRODUCTION: The aim of this study was to investigate the relationship between smoking and the prevalence of apical periodontitis and root canal treatment in hypertensive patients. METHODS: In a cross-sectional study, the records of 100 hypertensive patients, 50 smokers and 50 nonsmokers, were examined. Periapical status of all teeth was assessed by using the periapical index score. RESULTS: Apical periodontitis in 1 or more teeth was found in 92% of smoker patients and in 44% of nonsmoker subjects (P=.000; odds ratio [OR], 16.8; 95% confidence interval [CI], 4.6-61.3). One or more root-filled teeth were found in 58% and 20% of smoker and nonsmoker subjects, respectively (P < .01; OR, 5.5; 95% CI, 2.3-13.5). Among smoker hypertensive patients, 6% of the teeth had apical periodontitis, whereas in the nonsmoker subjects, 2% of teeth were affected (P < .01; OR, 3.3; 95% CI, 2.0-5.4). The percentage of root-filled teeth in the smoker and nonsmoker groups was 3.6% and 1.2%, respectively (P < .01; OR, 2.9; 95% CI, 1.6-5.5). CONCLUSIONS: The prevalence of apical periodontitis and root canal treatment was significantly higher in smoker hypertensive patients compared with nonsmoker subjects.

Single-rooted maxillary first molar with a single canal: endodontic retreatment.

This case report presents an unusual root canal system in a maxillary first molar tooth: a single canal in a single root. The endodontic access cavity displayed only 1 canal orifice. This case demonstrated that: 1) clinicians must have adequate knowledge about root canal morphology and its variations; 2) the location and morphology of root canals should be identified radiologically before the root canal treatment; and 3) careful examination of radiographs and the internal anatomy of teeth is essential.

Dentigerous cyst associated with a formocresol pulpotomized deciduous molar.

This report presents a case of dentigerous cyst associated with a formocresol pulpotomized deciduous molar detected during routine examination. Dentigerous cyst is an epithelial-lined developmental cavity that encloses the crown of an unerupted tooth at the cementoenamel junction. The present case describes a 9-year-old girl sent to the dental clinic by her dentist, who had accidentally discovered in the panoramic radiograph a single, unilocular, well-defined, radiolucent area enclosing the second left unerupted mandibular premolar. The second left primary molar had been pulpotomized 2 years before and buccal swelling without redness occurred near the tooth, evidencing bone expansion. Surgical treatment was carried out, the tooth was extracted, and a cystectomy was performed under local anesthesia in the dental office. The histological study confirmed the suspected diagnosis of dentigerous cyst. The relation between pulpotomy and dentigerous cysts is discussed.

Relationship of patient complaints and signs to histopathologic diagnosis of pulpal condition.

The correlation between the histopathologic examination of pulp biopsy specimens and patients' complaints and signs was investigated. The sensitivity, specificity and reliability of each complaint and sign, and the characteristics of pain that are associated with treatable and untreatable pulp states is proposed. Pulp specimens were obtained from teeth that required endodontic treatment. Clinical data were recorded to identify each patient's complaints. The pulp specimens were processed and the histopathologic diagnoses were categorised and correlated with the patients' complaints. Of the 240 cases, 100 (41.7%) were diagnosed as atrophic pulp or pulposis; 4 (1.7%) as acute pulpitis; 64 (26.7%) as transitional stage; 56 (23.3%) as chronic pulpitis, and 16 (6.7%) as acute pulpitis superimposed on a chronic pulpitis. Results showed that previous pain (p < 0.05), spontaneous pain (p < 0.01), and prolonged pain on cold stimuli (p < 0.05), were significantly more frequent in the patients with chronic pulpitis compared to those with pulposis or transitional stage. We concluded that clinicians must consider the sensitivity and specificity of patient complaints and signs in order to perform a diagnosis based upon clinical evidence.

Lichenoid reaction associated to amalgam restoration.

Hypersensitivity to mercury associated with amalgam restorations may occur and present in one of two different ways. Most commonly it presents as an oral lichenoid reaction affecting oral mucosa in direct contact with an amalgam restoration and represents a delayed, type IV, cell mediated immune response to mercury or one of the other constituents of the dental amalgam. We report a case of oral lichenoid reaction associated to amalgam restoration. A 38 year-old woman presented a caries lesion of tooth #37. A Blacks class I preparation was performed and filled with amalgam. After 19 months, intra-oral examination revealed atrophic lesion, lightly erythematous, affecting the left buccal mucous. The lesion contacted directly with the amalgam restoration in the lower first molar. The right buccal mucosa was normal. His medical history was unremarkable, he was taking no medication and had no known allergies. However, the patient had felt certain rare sensation in that zone when eating sharp meals. Biopsy showed histological changes compatible with oral lichen planus. The patient decided not to change again the restoration, because she did not have important annoyances and she did not wish to be treated again. Other restorations were performed with composite resins, and no reaction was evidenced in the mucosa.