A retrospective study of pulpal response in vital adult teeth prepared for complete coverage restorations at ultrahigh speed using only air coolant

Polytetrafluoroethylene tape to combat tooth sensitivity during complete mouth rehabilitation

Dentin sensitivity is a common complaint from patients during and after tooth preparation for complete coverage restorations. Techniques to reduce sensitivity during tooth preparation include immediate dentin sealing and application of desensitizers. However, managing dentin sensitivity during complete mouth rehabilitation on natural teeth can be challenging, especially for patients with dentin hypersensitivity. A technique to protect the prepared teeth during complete mouth rehabilitation using polytetrafluoroethylene (PTFE) tape is described.

Incidence and influential factors in pulp necrosis and periapical pathosis following indirect restorations: a systematic review and meta-analysis

BACKGROUND

Restoring vital teeth with indirect restorations may threaten dental pulp integrity. However, the incidence of and influential factors on pulp necrosis and periapical pathosis in such teeth are still unknown. Therefore, this systematic review and meta-analysis aimed to investigate the incidence of and influential factors on pulp necrosis and periapical pathosis of vital teeth following indirect restorations.

METHODS

The search was conducted in five databases, using MEDLINE via PubMed, Web of Science, EMBASE, CINAHL, and Cochrane Library. Eligible clinical trials and cohort studies were included. The risk of bias was assessed using Joanna Briggs Institute's critical appraisal tool and Newcastle-Ottawa Scale. The overall incidences of pulp necrosis and periapical pathosis following indirect restorations were calculated using a random effects model. Subgroup meta-analyses were also performed to determine the potential influencing factors for pulp necrosis and periapical pathosis. The certainty of the evidence was assessed using the GRADE tool.

RESULTS

A total of 5,814 studies were identified, of which 37 were included in the meta-analysis. The overall incidences of pulp necrosis and periapical pathosis following indirect restorations were determined to be 5.02% and 3.63%, respectively. All studies were assessed as having a moderate-low risk of bias. The incidence of pulp necrosis following indirect restorations increased when the pulp status was objectively assessed (thermal/electrical testing). The presence of pre-operative caries or restorations, treatment of anterior teeth, temporization for more than two weeks, and cementation with eugenol-free temporary cement, all increased this incidence. Final impression with polyether and permanent cementation with glass ionomer cement both increased the incidence of pulp necrosis. Longer follow-up periods (> 10 years) and treatment provided by undergraduate students or general practitioners were also factors that increased this incidence. On the other hand, the incidence of periapical pathosis increased when teeth were restored with fixed partial dentures, the bone level was < 35%, and the follow-up was > 10 years. The certainty of the evidence overall was assessed as low.

CONCLUSIONS

Although the incidences of pulp necrosis and periapical pathosis following indirect restorations remain low, many factors affect these incidences that should thus be considered when planning indirect restorations on vital teeth.

DATABASE REGISTRATION

PROSPERO (CRD42020218378).

Replacement of an existing maxillary anterior fixed dental prosthesis, redo another fixed dental prosthesis, or convert to implants

OBJECTIVE

The purpose of this article is to discuss the considerations that need to be evaluated when considering the replacement of an existing maxillary anterior fixed dental prosthesis (FDP) with another FDP, or when to consider converting to implants and individual crowns on the previous abutment teeth.

OVERVIEW

The need to replace unesthetic or failing maxillary anterior FDPs is something all restorative dentists will be faced with multiple times in their careers. Given the emphasis over the past few decades on utilizing implants for tooth replacement as opposed to a tooth supported FDP, the question becomes when is converting the existing FDP to implants and single crowns an appropriate choice, as opposed to redoing a new FDP. This article will focus on the risks of choosing to convert to an implant solution, and the risks of redoing the tooth supported FDP. Multiple systematic reviews on each approach will be used to aid in the decision process. The most significant risks for both approaches will be identified, and a chart of the key parameters to assess will be presented, along with their impact.

CONCLUSIONS

The statistical outcomes at 5 and 10 years of tooth supported FDPs, and Implant based restorations are very similar if certain clinical parameters are met, namely vital healthy abutment teeth for the FDP, and adequate bone and soft tissue for the implant-based restoration. If one abutment tooth is compromised the long-term prognosis drops significantly and converting to an implant-based restoration may be more predictable. Similarly, if adequate bone and soft tissue cannot be obtained through surgical augmentation procedures, using a connective tissue graft for the ridge, and redoing the FDP may obtain a more acceptable esthetic result.

CLINICAL SIGNIFICANCE

A significant number of maxillary anterior FDPs exist that will need replacement in the future. Given the desire of many dentists to utilize implants when possible, there can be a tendency to automatically treatment plan an implant-based approach for replacement of the existing FDP. Certainly, most clinicians would favor an implant-based tooth replacement rather than preparing unrestored teeth to place an FDP, but when an existing FDP exists, the teeth have already been prepared for full coverage in most instances. In addition, for most long term existing FDPs, there is a significant change in the vertical and horizontal dimension of the bone and soft tissue that can make getting an acceptable esthetic result with an implant challenging. This article provides a systematic approach to identifying when redoing the FDP may be preferable, or when converting to an implant-based approach is a better choice.

Pulpal and Periapical Status of the Vital Teeth Used as Abutment for Fixed Prosthesis-A Systematic Review and Meta-Analysis

PURPOSE

This is a systematic review to identify the incidence of pulp necrosis and/or periapical changes among vital teeth which are used as an abutment for crown and fixed partial dentures (FPDs).

MATERIALS AND METHODS

Two reviewers independently searched two electronic databases, PubMed and Scopus. The search was complemented from references of included studies and published reviews. Studies published in the English language through January 2021 that had assessed and documented the clinical and radiographic failure of crown or FPD in vital permanent teeth due to pulpal or periapical pathology with a follow-up of at least 12 months were selected. Data screening, data collection and extraction of data was performed. Quality of studies involved was analyzed using the Newcastle-Ottawa Quality Assessment Scale for cohort studies. Meta-analysis was done using random effects model. Publication bias was assessed using funnel plots.

RESULTS

Electronic searches provided 10,075 records among which 20 studies were selected for systematic review and 7 studies were selected for meta-analysis. With respect to quality assessment, all the studies involved were considered as high quality as the score in scale ranged between 6 and 9 as per the Newcastle-Ottawa Quality Assessment Scale for cohort studies. The meta-analyses showed that there was no statistically significant difference in the incidence of the loss of pulp vitality or pulp necrosis through clinical and radiographic examination with the follow up period of 5 years: p < 0.001, 95% CI: 0.96-1.00, I² = 77.84%; 10 years: p < 0.001, 95% CI: 0.88-0.95, I² = 93.59%; 15 years: p < 0.001, 95% CI: 0.92-0.96, I² = 94.83%; and 20 years: p < 0.001, 95% CI: 0.94-0.96, I² = 95.01%.

CONCLUSIONS

The meta-analysis revealed clinical and radiographic success rate ranging between 92% to 98% at different follow up periods ranging between 5 years and 20 years. Future high-quality randomized clinical controlled trials with a larger population are required to confirm the evidence as only observational studies were considered in this paper.

Coronal Restoration as a Predictor of Periapical Disease in Non-Endodontically Treated Teeth

Objectives

To compare the frequency of apical periodontitis (AP) in non-endodontically treated teeth restored with full coverage crowns, amalgam and resin composite fillings, and to disclose the association of type and quality of coronal restoration with periapical disease.

Material and Methods

The cross-sectional study involved 597 subjects who attended the Dental Clinic of the Clinical Hospital Centre, Rijeka, Croatia for the first time. Data were collected by means of a clinical and radiological survey. The following data were recorded for all permanently restored non-endodontically treated teeth: the type, the quality of coronal restoration according to clinical and radiographic criteria for marginal integrity as well as the recurrent caries presence, periapical status and marginal bone loss. Chi-square tests were used to analyze the difference in periapical status regarding the type and the quality of restoration. The multivariate logistic regression analysis was used to assess the effect of explanatory tooth-specific variables on periapical status.

Results

There was no significant difference in the proportion of AP with regards to the type and material of adequate quality coronal restorations (χ²=5.000, P=0.082). The regression analysis revealed significant positive associations with outcome variable (AP) for crowns (OR=3.39; P<0.001), recurrent caries (OR=4.67; P<0.001) and premolar teeth (OR=1.73; P=0.002).

Conclusion

If the quality of restorations is adequate, there is no difference in the periapical status of non-endodontically treated teeth regarding the type and material of coronal restoration.

A survey assessing the knowledge and perception of dental practitioners on the need for prophylactic endodontic treatment in abutment teeth for fixed partial dentures

Background:

Tooth preparation for fixed prosthodontic procedures often induces enough thermal or mechanical stresses on the pulp. The extent of pulpal injury and ability to repair depends on factors like amount of remaining dentin, extent of heat produced, and permeability of dentinal tubules. However, there is no infallible method to predict the pulpal response and so the treatment outcome.

Aim:

This survey tries to assess the knowledge and perception among dental practitioners on the need for prophylactic endodontic therapy in abutment teeth for fixed partial denture (FPD).

Setting and Design:

Questionnaire-based survey.

Methodology:

An observational study was then conducted among 303 dental practitioners in the state of Tamil Nadu and 250 participants responded.

Statistical Analysis Used:

Descriptive statistics and multiple linear regression analysis.

Results and Conclusion:

The survey further imparts light on the clinical outcomes that help minimize the incidence of biological failure underneath a FPD.

Effect of Surface Coating on Bond Strength between Etched Feldspar Ceramic and Resin-Based Luting Agents

This study evaluated adhesive protocols (silane, silane and unfilled resin, and universal adhesive) of bond strength between feldspar ceramic and resin-based luting agents (RBLAs). Thirty ceramic disks were embedded into acrylic resin, polished, etched, and randomly divided into 6 groups: S-RC: silane (S) and light-cured resin cement (RC) (RelyX Veneer; 3M ESPE); SB-RC: S followed by bond (B) (Clearfil SE Bond, Kuraray) and RC; UA-RC: universal adhesive (UA) (Single Bond Universal; 3M ESPE) and RC; flowable composite resin (F) was used on groups S-F, SB-F, and UA-F, and luting agent cylinders were built. The response variables (n=20) were microshear bond strength (MPa), characteristic strength (σ₀, MPa), and Weibull modulus (m). The RC groups presented similar bond strengths regardless of whether or not bond was used. The S-F group with only silane application showed the highest bond strength, while the universal adhesive showed the lowest bond strength. The reliability was only affected in the UA-RC group, which was lower than the S-F group. Silane application is fundamental since the universal adhesive only decreased the bond strength between the feldspar ceramic and the RBLAs. Overall, the use of unfilled resin did not positively influence bond strength.

Construction and in vitro test of a new electrode for dentin resistance measurement

It is necessary to reduce the tooth substance before treating a tooth with a dental crown. The preparation often requires reduction of the dentin. This results in a dentin wound and a thinner substance over the pulp, increases the risk of inflammation, and could result in necrosis of the pulp. To give the dentist information about the amount of dentin over the pulp during preparation, the Prepometer was developed. The function of this device is based on the measurement of the electric resistance of the tooth substance. The measuring behavior of the first-generation Prepometer is characterized by smaller values of electric resistance before reaching full contact of the measuring head to the dentin surface and the actual value RT. This measuring behavior can mislead inexperienced therapists with inaccurate values that suggest thinner dentin than the reality. In this study, a new electrode based on the technology of active guard drive was constructed to overcome this issue. The results show that improvement in the measuring behavior of the new electrode could be achieved, eliminating the earlier disadvantage of the Prepometer.

A prospective clinical trial on the influence of a triamcinolone/demeclocycline and a calcium hydroxide based temporary cement on pain perception

INTRODUCTION

The aim of this clinical trial was to compare the degree of short term post-operative irritation after application of a triamcinolone/demeclocycyline based or a calcium hydroxide based provisional cement.

METHODS

A total of 109 patients (55 female and 54 male; mean age: 51 ± 14 years) with primary or secondary dentinal caries were randomly assigned to the two treatment groups of this biomedical clinical trial (phase III). Selection criteria were good systemic health and treated teeth, which were vital and showed no symptoms of pulpitis. Up to three teeth were prepared for indirect metallic restorations, and the provisional restorations were cemented with a triamcinolone/demeclocycyline (Ledermix) or a calcium hydroxide (Provicol) based material. The intensity of post-operative pain experienced was documented according to the VAS (4, 12, 20, 24, and 82 h) and compared to VAS baseline.

RESULTS

A total of 159 teeth were treated (Ledermix: 83 teeth, Provicol: 76 teeth). The minor irritation of the teeth, experienced prior to treatment, was similar in both groups; however, 4 h after treatment this value was significantly higher in the Provicol group than in the Ledermix group (p < 0.005, t-test). After 12 h, the difference was no longer significant. The number of patients taking analgesics for post-treatment pain was higher in the Provicol group (n = 11/53) than in the Ledermix group (n = 3/56).

CONCLUSIONS

The patients had no long term post-operative pain experience in both groups. However, within the first hours after cementation the sensation of pain was considerably higher in the Provicol group than in the Ledermix group.

Resin strengthening of dental ceramics—The impact of surface texture and silane

OBJECTIVES

To examine the effect of porcelain surface texture achieved utilising three clinically relevant surface preparation methods prior to silane and unfilled resin application on the flexure strength of a low fusing feldspathic porcelain.

MATERIALS AND METHODS

Five hundred and forty dentine disc-shaped specimens (15.0mm diameter and 0.9mm thickness) were condensed, fired and allocated to 18 groups. Six groups were stored as-fired, six were alumina abraded and six were acid-etched. Samples were coated with silane, unfilled resin or both prior to bi-axial flexure testing. Group means were compared utilising a three factor design general linear model and post hoc all paired Tukey tests at P<0.05. Weibull analysis was employed to examine the reliability of the strength data. Profilometry was used to characterise the surface texture of the specimen surfaces.

RESULTS

Alumina abraded and acid-etched specimens had significantly lower flexure strengths than the as-fired specimens. A significant difference between the degree of strengthening observed following unfilled resin application on the three surface texture investigated was observed (P<0.001). Silane application prior to resin coating resulted in no further significant increases in the mean bi-axial flexure strengths of the three surface textures. The as-fired surfaces had a low frequency of irregular amplitude defects, alumina abraded surfaces had an increased frequency of regular amplitude defects whilst the acid-etched surface consisted of an increased frequency of irregular amplitude defects.

CONCLUSION

The strengthening mechanism whilst dependent on surface texture was independent of defect severity. No significant strengthening occurred following silane priming suggesting that, for the unfilled resin utilised, the strengthening mechanism was not enhanced by improved resin-ceramic adhesion.

Predictors of Root Canal Treatment in Teeth With Full Coverage Restorations

This case-control study sought to identify variables predictive of subsequent root canal therapy (RCT) in teeth receiving full coverage restorations. The University of North Carolina School of Dentistry's computerized treatment database was used to identify all patients receiving a single-unit crown on a nonendodontically treated permanent tooth from January 1, 1998 through December 31, 2002. These patients then were classified either as cases (those whose crowned teeth received RCT before July 1, 2004) or controls (those whose crowned teeth did not). Computerized data, chart entries, and dental radiographs were examined to determine pre-, intra-, and postoperative factors of interest. In the final multivariable logistic regression model that included 66 cases and 71 controls, younger age (p = 0.005) and greater extent of coronal and root destruction (p = 0.020) remained statistically significant predictors of case status, though many potentially important predictors were unavailable through chart review. Patients could benefit if prospective studies were conducted to identify factors predictive of subsequent endodontic involvement in newly crowned teeth.

The effect of cavity preparation on substance P expression in human dental pulp

Substance P (SP) plays an important role during neurogenic inflammation of dental pulp. The purpose of this study was to use a radioimmunoassay for determining the effect of cavity preparation on SP expression in healthy human dental pulp. Ten pulp samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. Deep cavity preparation (<1 mm remaining dentine thickness) was performed before extraction in five of these bicuspids. All samples were processed and I-SP labeled; SP was quantified by competition assay. The results revealed SP expression in all human pulp samples. Mann-Whitney's U test revealed statistically significant higher expression in pulp from teeth where cavity preparation had been performed compared to control values (p < 0.05). These findings suggest that SP is released during common dental procedures (such as cavity preparation) and its expression may have an important clinical significance in terms of experiencing inflammation and pain.

Patient's age and extent of coronal and root destruction predict root canal treatment subsequent to after a full-cast crown

DESIGN

A case-control study was carried out at the University of North Carolina School of Dentistry in the US. PARTICIPANT SELECTION: Dental charts from the university's dental clinical were audited for patients who had a single-cast crown between 1 January 1998 and 31 December 2002. Cases were defined as individuals who underwent root canal treatment at some time after the insertion of a single-cast crown up to 1 July 2004. The control group consisted of people who did not have root canal treatment after the insertion of a full-cast crown.

DATA ANALYSIS

A list of 24 clinical factors was compared between groups (Table 1). Multiple logistic regression analysis was used to determine which preoperative nonprocedural factors were predictive of root canal treatment subsequent to a full-cast crown.

RESULTS

A total of 6612 single-cast crowns (cast metal or porcelain fused to metal) were inserted during the 5-year period of interest. Of these, 5743 crowns, identified from 3357 patients' records (ie, the study subjects), were determined not to have undergone root-canal treatment prior to full-cast crown restorative treatment. Ninety-two subjects were initially determined to be eligible cases; ninety-two subjects were also therefore randomly selected from the remaining 3265 subjects to make up the control group. Twenty-six of the cases and 21 members of the control group were excluded because of incomplete records. The final case and control groups comprised 66 and 71 subjects respectively. Only subjects' age at the time of restorative treatment and their post-cementation tooth sensitivity was statistically significantly different between the two groups (P<0.05). Multiple logistic regression determined the statistically significant (P<0.05 ) predictors of case status: these were a patient's age and also the subgroup to which they were allocated according to the extent of pre-operative coronal and root destruction, on the basis of the restorative core size (more than three restored surfaces; Table 2).

CONCLUSION

The age of a patient and the extent of coronal and root destruction can be used to predict the future need for root canal treatment on teeth for which a single-cast crown is planned.