Frequency of additional treatments in relation to the number of root filled canals in molar teeth in the Swedish adult population.

AIM: To investigate the 5-year frequency of additional treatments in relation to the number of reported root filled canals in molar teeth in Sweden. METHODOLOGY: The cohort included first and second molars in adult individuals who were registered with a root filling performed in 2009. Treatment codes corresponding to root fillings of teeth with from one up to four root filled canals were identified in the Swedish Social Insurance Agency database. The studied additional treatments were extraction, non-surgical root canal retreatment and endodontic surgery during the subsequent 5 years, identified by corresponding codes for these treatments registered on these specific teeth. Differences in the frequency of additional treatments based on the number of root filled canals were analysed using chi-square test and considered statistically significant at P < 0.05. RESULTS: In 2009, root fillings on a first or second molar tooth were registered in 100 720 individuals. The study included 32 901 maxillary first molars (6.4% with four root filled canals), 12 763 maxillary second molars (3.3% with four root filled canals), 37 703 mandibular first molars (19.2% with four root filled canals) and 17 353 mandibular second molars (3.7% with four root filled canals). The total frequency of additional treatments was 14.3% (n = 14 425) during the 5-year observational period. Additional treatments were more frequent in teeth with 1-3 root filled canals compared to teeth with four root filled canals for maxillary first molars (15.2% vs. 12.7%, P = 0.002), maxillary second molars (13.8% vs. 9.1%, P = 0.007) and mandibular first molars (14.0% vs. 10.7%, P < 0.001) but not mandibular second molars (15.6% vs. 13.7%, P = 0.200). CONCLUSIONS: Over 5 years, 85.7% of the included teeth were not registered with any additional treatments. Maxillary first and second molars and mandibular first molar teeth had a greater frequency of additional treatments when ≤3 root canals were filled compared to four canals.

Coronal restoration of the root filled tooth - a qualitative analysis of the dentists' decision-making process.

AIM: To describe the decision-making process of the general dental practitioner (GDP) underlying the choice of coronal restoration of a root filled tooth. METHODOLOGY: GDPs were strategically selected with respect to gender, age, undergraduate dental school, service affiliation and duration of professional experience. Semistructured in-depth interviews were conducted, focusing on the informant's personal experience of the process which leads to a decision as to how to restore a root filled tooth. The informants were invited to describe in their own words the latest two cases involving decisions of direct or full crown restorations respectively. The interviews were digitally recorded and transcribed verbatim. Interviews from 14 informants, aged 27-64 (mean age 46 years), were included and analysed according to Qualitative Content Analysis. RESULTS: A theme (latent content) was identified: Clinical factors were considered important but were overruled by context and patient opinions, if in conflict. Three main categories, including seven subcategories (manifest content), were identified. The categories were clinical factors, contextual factors and patient's views. Clinical factors underlying the GDPs' decision included the current dental status and the estimated longevity of the intended restoration. In certain cases, contextual factors were also of importance, either supporting the GDPs' decision or modifying it. However, the patient's views played a decisive role in the final choice of coronal restoration, leading to either mutual acceptance or a compromise, taking into account the patient's economic status and opinions. CONCLUSIONS: With respect to coronal restoration of a root filled tooth, the GDPs' decision-making process was based not only on clinical factors, but also on decisive contextual factors and consideration of the patients' views.

Tooth survival following root canal treatment by general dental practitioners in a Swedish county - a 10-year follow-up study of a historical cohort.

AIM: To evaluate the 10-year survival rate of root filled teeth treated by general dental practitioners (GDPs), and to identify possible prognostic factors. METHODOLOGY: In 2006, 3676 individuals had at least one tooth root filled by a GDP within the Norrbotten Public Dental Service, Sweden. Over the next 10 years, 331 individuals died and were excluded. A random sample of 302 of the remaining individuals was included in the study, of whom 280 (n = 280 teeth) were included in the analysis. Dental records were reviewed retrospectively by a calibrated researcher to collect predetermined data regarding individual, pre-operative, intra-operative and post-operative factors. The outcome measure was tooth extraction over time, and cases with no events were censored, regardless of apical status or symptoms, until last known date of tooth survival. In case of missing data, individuals were recalled for a control visit. Kaplan-Meier survival tables and Cox regression models were used for analysis. P < 0.05 was considered statistically significant. RESULTS: The cumulative 10-year survival was 81.7% (standard error: 2.6%), and the mean incidence of tooth extraction during the 10 years was 1.8% per year. The univariate analysis identified three possible prognostic factors (P < 0.05) that were associated with extraction: molars, two or more emergency inter-appointment visits during the treatment, and root canal treatments consisting of five or more separate sessions. A multivariate regression analysis revealed no significant relationships for the variables gender, tooth type, number of contacts, any emergency visits during endodontic treatment, number of sessions to complete endodontic treatment, pulp diagnosis, or type of permanent restoration and extraction. CONCLUSIONS: The mean incidence of tooth loss over the first 10 years after completion of root canal treatment performed by a GDP was approximately 2% per year. No prognostic factors could be identified.

European Society of Endodontology position statement: Management of deep caries and the exposed pulp.

This position statement on the management of deep caries and the exposed pulp represents the consensus of an expert committee, convened by the European Society of Endodontology (ESE). Preserving the pulp in a healthy state with sustained vitality, preventing apical periodontitis and developing minimally invasive biologically based therapies are key themes within contemporary clinical endodontics. The aim of this statement was to summarize current best evidence on the diagnosis and classification of deep caries and caries-induced pulpal disease, as well as indicating appropriate clinical management strategies for avoiding and treating pulp exposure in permanent teeth with deep or extremely deep caries. In presenting these findings, areas of controversy, low-quality evidence and uncertainties are highlighted, prior to recommendations for each area of interest. A recently published review article provides more detailed information and was the basis for this position statement (Bjørndal et al. 2019, International Endodontic Journal, doi:10.1111/iej.13128). The intention of this position statement is to provide the practitioner with relevant clinical guidance in this rapidly developing area. An update will be provided within 5 years as further evidence emerges.

Comparative analysis of general dental practitioners' fees and scheduled fees for root canal treatment and coronal restorations in the adult population of Sweden: a 5-year follow-up of data from the Swedish Dental Register.

AIM: To investigate the fees charged by Swedish dentists for root fillings, coronal restorations and further dental interventions during a follow-up period of 5-6 years. METHODOLOGY: A total of 248 299 root fillings were linked with the tooth, the patient and the provider and entered into the Swedish Social Insurance Agency register in 2009. The data register also recorded the subsidy-based (scheduled) fee and the fee actually charged for the root fillings. Fees charged for direct or indirect coronal restorations and additional interventions during the follow-up period were also recorded. One-way anova and t-test were used for statistical analysis. RESULTS: The mean overall fee charged for a root filling was approximately 332 Euro and differed only marginally (13 Euro) from the scheduled fee. The total mean fee for preservation of a root filled tooth was 717 Euro, which included the root canal treatment, the coronal restoration and any additional interventions during the follow-up period. The fees for indirectly restored root filled teeth were significantly higher (1105 Euro) than for directly restored teeth (610 Euro), despite further additional treatment (P < 0.001). The mean fee for teeth which were subsequently extracted was higher (769 Euro) than for the retained teeth (711 Euro) (P < 0.001). CONCLUSIONS: Fees charged by Swedish dentists for root canal treatment were in accordance with the scheduled fees. The overall mean fee was significantly higher for root filled teeth with indirect restorations than for teeth with direct coronal restorations. However, prospective clinical cost-effectiveness studies are needed to analyse the total costs.

Demographic factors in Swedish adults undergoing root filling and subsequent extraction of a maxillary first molar: a comparative study.

AIM: To study the demographics of Swedish adults who had received a root filling, followed by extraction during the following 5-6 years in comparison with subjects who had undergone a corresponding root filling with an uneventful outcome. METHODOLOGY: The root filled maxillary first molar was chosen as the comparison model. The Swedish Social Insurance Agency provided data on all teeth reported as root filled in Sweden during 2009. A comparison group, equally large as the study group, was constructed by randomly selecting subjects with root filled maxillary first molars, which had not subsequently been extracted, that is, an uneventful outcome. Demographic data on the subjects were obtained from Statistics Sweden: country of birth, disposable income, educational level, age, civil status and gender. Chi-square, t-tests and logistic regression were used for statistical analyses. RESULTS: In the year 2009, 36 139 maxillary first molar teeth were reported to have been root filled, 4362 (12.1%) of which were then recorded as extracted during the following 5-6 year period. Only minor intergroup differences were noted: 86.5% of the study group were Swedish-born, compared with 84.4% of the comparison group (P = 0.007). Women comprised 53.2% of the study group and 50.5% (P = 0.01) of the comparison group. There was an association between extractions and gender as well as age; men had a lower odds ratio (OR) for extraction OR, 0.87; confidence interval (CI), 0.80-0.95. For every additional year, the chance for extraction was higher OR, 1.01; CI, 1.01-1.01. No other significant differences were detected. CONCLUSIONS: There was only little or no demographic differences between the study group, comprising Swedish adults who had undergone root filling of one of their maxillary first molars in 2009 and subsequent extraction during the following 5-6 years, and the comparison group, with uneventful outcomes after a corresponding root filling.

Formation of a hard tissue barrier after experimental pulp capping or partial pulpotomy in humans: an updated systematic review.

The aim was to update a systematic review of pulp capping and partial pulpotomy by Olsson et al. (2006), by evaluating new evidence on formation of a hard tissue barrier after pulp capping and partial pulpotomy of experimental exposures in humans. PubMed (01-01-2005 to 01-03-2014) and CENTRAL were searched using specific keywords. Hand searches were made and the level of evidence for each included article was evaluated by the authors. The evidence of the conclusions was graded as strong, moderately strong, limited or insufficient. The initial search in PubMed yielded 215 abstracts. Hand searches of reference lists yielded no additional original scientific articles. After a selection process and interpretation, 22 articles were included and rated for level of evidence: no article was rated as high and seven as moderate. Overall the methodological quality of studies has improved since the previous systematic review was published in 2006. The conclusions are that there is limited scientific evidence that application of calcium hydroxide or mineral trioxide aggregate to an exposed pulp frequently results in formation of a hard tissue barrier, whereas adhesives or enamel matrix derivatives do not. There is insufficient scientific evidence that mineral trioxide aggregate promotes hard tissue formation more frequently than calcium hydroxide.

Twenty-year follow-up of root filled teeth in a Swedish population receiving high-cost dental care.

AIM: To study the 20-year survival rate and periapical status of root filled teeth in a Swedish population requiring high-cost dental care and to identify factors related to survival and normal periapical status at follow-up. METHODOLOGY: The study population comprised 104 patients selected from four local health insurance districts with treatment plans including radiographs submitted for approval for reimbursement from the Swedish National Dental Insurance in 1977. In 1998, a clinical and radiographic follow-up examination was conducted, to register the status of 449 teeth identified as root filled at baseline. Differences in tooth survival and periapical status at follow-up, with reference to periapical status and quality of root filling at baseline, were analysed by chi-square tests. Multiple regression analysis was used to describe tooth survival and normal periapical status at follow-up, with the explanatory baseline variables: tooth type, type of restoration, type of post, quality of root filling, periapical status, marginal bone loss and caries. Differences were considered significant at a 5% level. RESULTS: Two hundred and ninety (65%) of the root filled teeth survived at follow-up. Baseline variables associated with low odds for tooth survival were mandibular molar, maxillary premolar, prefabricated posts other than screw posts, severe marginal bone loss, caries and apical periodontitis (AP). Normal periapical status at follow-up was registered in 49% of the root filled teeth. Baseline variables associated with low odds for normal periapical status (high risk for AP) at follow-up were mandibular molar, maxillary premolar, AP, severe marginal bone loss and inadequate root filling quality. Of the root filled teeth with AP at baseline, 42% had been left untreated during the observation period, and at follow-up, the AP persisted in 57% of these teeth. CONCLUSIONS: After 20 years, 65% of the root filled teeth had survived and one-third remained with a sound periapical condition, without any further treatment. Almost half of the APs registered at baseline were left without treatment, and more than half of them persisted after 20 years.

Endodontic complications in teeth with vital pulps restored with composite resins: a systematic review.

Composite resin is used extensively for restoration of teeth with vital pulps. Although cell culture studies have disclosed harmful effects on pulpal cells, any untoward clinical effects, manifest as adverse pulpal responses, have yet to be determined. This study comprises a systematic review, designed to address the question of whether the risk of endodontic complications is greater with composite resin restorations than with other restorative materials, such as amalgam. The study methodology involved (i) formulation of the research question, (ii) construction and conduct of an extensive literature search with (iii) interpretation and assessment of the retrieved literature. A search of the medical database PubMed was complemented with a search of the Controlled Trials Register (CENTRAL). The initial search yielded 1043 publications, the abstracts of which were read independently by the authors. After additional searches, 10 studies were included in the review. In all the included studies, the level of evidence was assessed as low. No conclusions could therefore be drawn. The included studies reported few, if any, endodontic complications. Little or no differences emerged between teeth restored with composite resins and those restored with amalgam. To determine whether composite resin restorations of teeth with vital pulps are associated with an increased risk for development of endodontic complications such as apical periodontitis, further evidence is needed, from well-constructed studies with a large number of participants.

Effects of bacterial products on the activity of odontoblast-like cells and their formation of type 1 collagen.

AIM: To study how products released from different bacteria in a deep carious lesion affect the metabolic activity of odontoblast-like cells and their ability to produce the major organic component of dentine, collagen 1. METHODOLOGY: MDPC-23 cells were exposed to supernatants from biofilm cultures of strains isolated from the deepest part of a carious lesion as well as from a clinical isolate of Enterococcus faecalis. Lipoteichoic acid (LTA) and lipopolysaccharide (LPS) were used for comparison. Cell activity was assessed using an methyl-thiazolyl-diphenyl tetrazolium bromide (MTT) assay, and collagen 1 levels were determined by ELISA. RESULTS: The lesion microflora was dominated by Lactobacillus spp. Neither extracellular products from the isolates nor LPS affected the activity of the MDPC-23 cells, whereas extracellular products from E. faecalis and LTA significantly reduced total cell activity (P < 0.01). Enterococcus faecalis had an inhibitory effect upon collagen 1 production by the cells, whereas no such effect or even a slight stimulatory effect was seen for the isolates from the deep carious lesion. CONCLUSIONS: These studies indicate that culture supernatants from E. faecalis reduced the metabolic activity of odontoblast-like cells as shown using the MTT assay. No effect was seen for supernatants from biofilms of bacteria recovered from a deep carious lesion. Different bacteria varied in their effects upon collagen 1 production suggesting that the nature of the bacterial species in a carious lesion may have a direct influence upon the ability of the odontoblasts to produce tertiary dentine.

Efficacy of lasers as an adjunct to chemo-mechanical disinfection of infected root canals: a systematic review.

The aim was to evaluate the efficacy of various types of lasers used as an adjunct to chemo-mechanical disinfection of infected root canals with the outcome measures 'normal periapical condition' or 'reduction of microbial load'. PubMed, CENTRAL and ISI Web of Knowledge literature searches with specific indexing terms and a subsequent hand search were made with stated limits and criteria. Relevant publications were retrieved, followed by interpretation. The quality of each included publication was assessed as high, moderate or low. The initial search process yielded 234 publications. All abstracts of these publications were read, and the reference lists of relevant publications were hand-searched. Ten articles were read in full text and interpreted according to a data extraction form. Five were included in the systematic review and were assessed. A meta-analysis was impossible to perform because the included studies were heterogeneous with regard to study design, treatment and outcome measures. Positive effects were reported; however, no concluding evidence grade could be made because each included study was judged to have low quality, primarily due to lack of a power analysis, blinding and reproducibility. The evidence grade for whether lasers can be recommended as an adjunct to chemo-mechanical disinfection of infected root canals was insufficient. This does not necessarily imply that laser should not be used as an adjunct to root canal treatment but instead underscores the need for future high-quality studies.

Dentine sialoprotein and collagen I expression after experimental pulp capping in humans using emdogain gel.

AIM: To characterize the hard tissue formed in human teeth experimentally pulp capped either with calcium hydroxide or with Emdogain Gel (Biora AB, Malmö, Sweden) - a derivative of enamel matrix (EMD), using two markers for dentine; dentine sialoprotein (DSP) and type 1 collagen (Col I). METHODOLOGY: Affinity-purified rabbit anti-Col I and anti-DSP polyclonal antibodies were used to stain histological sections from nine pairs of contra-lateral premolars that had been experimentally pulp amputated and randomly capped with EMDgel or calcium hydroxide. Twelve weeks after the teeth had been pulp capped, they were extracted, fixed, demineralized and serially sectioned prior to immunohistochemical staining. RESULTS: In the calcium hydroxide treated teeth DSP was seen in the new hard tissue which formed a bridge. DSP was also seen in the newly formed hard tissue in the EMDgel-treated teeth. Proliferated pulp tissue partly filled the space initially occupied by EMDgel and DSP-stained hard tissue was observed alongside exposed dentine surfaces as well as in isolated masses within the proliferated pulp tissue, although the new hard tissue did not cover the pulp exposure. DSP staining was also seen in the cells lining the hard tissue in both groups. Col I staining was seen in the newly formed hard tissue in both groups. CONCLUSIONS: The new hard tissue formed after pulp capping with EMDgel or calcium hydroxide contained DSP and Col I, considered to be markers for dentine. Thus, the newly formed hard tissue can be characterized as dentine rather than unspecific hard tissue.

Factors Associated with Extraction following Root Canal Filling in Adults.

Essentially, root fillings are performed to preserve natural teeth. Over time, however, some root-filled teeth will inevitably be extracted. The aim of this historical prospective cohort study in the adult Swedish population was to identify factors associated with extractions within 5 y of registration of a root filling. The cohort consisted of all those whose root fillings had been reported to the tax-funded Swedish Social Insurance Agency (SSIA) in 2009. Demographic data on the individuals registered with a root filling (sex, age, country of birth, disposable income, educational level, and marital status) were received from Statistics Sweden or the SSIA. Dental care setting, tooth type, and any registration of subsequent restorations within 6 mo were received from the SSIA. Multivariable regression analysis was used, and P < 0.05 was considered statistically significant. In total, 216,764 individuals had been registered with at least 1 root filling. Individuals (n = 824) without complete data were excluded from the analyses. After 5 y, 9.3% of the root-filled teeth had been registered as extracted. Logistic regression analysis found significant associations for all variables except country of birth, disposable income, and educational level. The highest odds ratios for extractions were associated with the type of restoration: teeth with no registration of any restoration and teeth with a direct restoration combined with a post were 3 times more likely to undergo extraction than teeth restored with an indirect restoration combined with a post and core. Overall, high odds ratios for extractions were associated with any type of composite restoration, including composite fillings and crowns combined with or without any post. In summary, after root filling in the Swedish adult population, several individual- and tooth-specific variables were associated with extraction. The reasons for the extractions remain to be studied further.

Randomized Clinical Trials on Deep Carious Lesions: 5-Year Follow-up.

Deep caries presents a dilemma in terms of which treatment that will render an optimal prognosis by maintaining pulp vitality with absence of apical pathology. Previously, 2 randomized clinical trials were performed testing the short-term effects of stepwise carious tissue removal versus nonselective carious removal to hard dentin with or without pulp exposure. The aim of this article was to report the 5-y outcome on these previously treated patients having radiographically well-defined carious lesions extending into the pulpal quarter of the dentin but with a well-defined radiodense zone between the carious lesion and the pulp. In this long-term study, 239 of 314 (76.2%) patients were analyzed. The stepwise removal group had a significantly higher proportion of success (60.2%) at 5-y follow-up compared with the nonselective carious removal to hard dentin group (46.3%) ( P = 0.031) when pulp exposures per se were included as failures. Pulp exposure rate was significantly lower in the stepwise carious removal group (21.2% vs. 35.5%; P = 0.014). Irrespective of pulp exposure status, the difference (13.3%) was still significant when sustained pulp vitality without apical radiolucency and unbearable pain was considered (95% confidence interval, 3.1-26.3, P = 0.045). After pulp exposure, only 9% ( n = 4) of the analyzed patients were assessed as successful, indicating that the prognosis is highly dubious following conventional pulp-capping procedures (direct pulp capping or partial pulpotomy) in deep carious lesions in adults. In conclusion, the stepwise carious removal group had a significantly higher proportion of pulps with sustained vitality without apical radiolucency versus nonselective carious removal of deep carious lesions in adult teeth at 5-y follow-up ( ClinicalTrials.gov NCT00187837 and NCT00187850).

Compressive fracture resistance of the marginal ridge in large Class II tunnels restored with cermet and composite resin.

Compressive fracture resistance of the marginal ridge was studied in large tunnel preparations, before and after restoration with cermet (Ketac Silver, ESPE), a universal hybrid composite (Superlux, DMG) and an experimental composite. Each group was represented by six tunnels in extracted upper premolars. The tunnels were prepared by the use of round burs up to size #6. Remaining ridge width was 1.5 mm and ridge height 1.7 mm in the contact area. The ridge was loaded to fracture by a rod placed perpendicular to the ridge. Generally this resulted in a shear fracture of the restoration. There was no significant reinforcement of the ridge by the cermet whereas the composites both reinforced by the same magnitude, averaging 62%. It was concluded that the ridge could be considered a "megafiller" where contact need to be preserved and contour protected against proximal and occlusal wear of the restoration. Clinically there would therefore be good reasons to save even ridge areas with very low inherent strength. Based on the present study composite resin might therefore be the filling material of choice for such tunnel preparations.