Analysis of endodontic therapy in patients irradiated for head and neck cancer

Postoperative pain in oncological patients subjected to nonsurgical root canal treatment: a prospective case-control study

OBJECTIVES

The purpose of this prospective study was to evaluate the incidence and intensity of postoperative pain in oncological patients with infected teeth subjected to nonsurgical root canal treatment or retreatment.

METHODS

Teeth with apical periodontitis from healthy control patients and oncological patients (n = 70 per group) were root canal treated/retreated and evaluated for the development of postoperative pain. Patients from the two groups were matched for tooth type, gender, clinical manifestation of apical periodontitis, and intervention type. A visual analogue scale (VSA) was used to evaluate the incidence of postoperative pain at 24 h, 72 h, 7d, and 15d after chemomechanical procedures. Data were statistically analyzed for the incidence and intensity of postoperative pain in the two groups.

RESULTS

Preoperative pain occurred in 10% of the individuals and in all these cases pain showed a reduction in intensity or was absent after endodontic intervention at 24-h evaluation. The overall incidence of postoperative pain at 24 h was 14% in oncology patients and 30% in controls (p = 0.03). At 72 h, the respective corresponding figures were 4% and 8.5% (p > 0.05). At 7 and 15 days, all patients were asymptomatic, irrespective of the group.

CONCLUSIONS

No significant differences in postoperative pain were found between control and oncological patients. The low incidence of postoperative pain observed in both groups supports the routine use of nonsurgical root canal treatment/retreatment as valid options in oncological patients.

CLINICAL RELEVANCE

Oncological patients had no increased risk of postoperative pain in comparison with control patients.

Clinical efficacy of endodontic protocols on reducing cultivable bacteria and endotoxin in infected root canal in patients submitted to head and neck radiotherapy: a randomised clinical trial

OBJECTIVES

Assess the efficacy of biomechanical preparation using a reciprocating system followed by final irrigation protocols, then intracanal medication, on reducing endotoxins and cultivable bacteria of infected teeth in irradiated patients.

MATERIALS AND METHODS

Twenty-two infected single-rooted canals in patients submitted to head and neck radiotherapy were prepared by reciprocating motion and 2.5% NaOCl. Patients were randomly divided into two groups of 11 patients before the final irrigation protocol: apical positive pressure (APP) or passive ultrasonic activation (PUA). Both groups were treated in two sessions, using Ca(OH)2 as intracanal medication for 14 days. Root canal content sampling was performed after canal access (S1), after biomechanical preparation plus the irrigation protocol (S2), and after intracanal medication (S3). Chromogenic limulus amoebocyte lysate assay measured endotoxin levels (EU/mL), and bacterial load was determined by culture techniques (CFU/mL).

RESULTS

Treatment protocols reduced bacterial counts after S2 in both groups (p = 0.01). S3 differed from S1 (p = 0.01), but not from S2 (p = 0.4). Endotoxin levels were reduced in both groups after S2 (P = 0.03) and were lower in S3 than in S2, with significant differences in the APP group (p = 0.03).

CONCLUSIONS

Biomechanical preparation using a reciprocating system and 2.5% NaOCl in irradiated teeth, followed by the irrigation protocol (APP or PUA), demonstrated efficacy in reducing endodontic contaminants. Ca(OH)2 as intracanal medication should be performed in irradiated patients with infected root canals.

CLINICAL RELEVANCE

This clinical study demonstrated that endodontic treatment in irradiated patients is efficacious at reducing bacterial load and endotoxin levels.

The dental management of patients irradiated for head and neck cancer

Patients undergoing radiotherapy for head and neck cancers are prone to a range of dental complications, including mucositis, trismus, xerostomia, radiation caries and osteoradionecrosis. Specific considerations include the preventive, restorative and rehabilitative management of such patients, and the prevention and treatment of complications. This article aims to highlight the current understanding and management of dental needs for patients who have had or will undergo radiotherapy.

Effects of direct therapeutic radiation on pulpal surface of root dentin: an in vitro study

The aims of the study were to analyze the effects of therapeutic radiation on human root dentin samples from the aspect of possible alterations in crystallinity, micro-morphology, and composition. Fifty-six root dentin specimens were divided into seven groups (0, 10, 20, 30, 40, 50, and 60 Gy). Scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analyses were performed on pulpal surfaces of root dentin after being irradiated by 6MV photon energy. Mineral compositions, Ca/P, P/N, Ca/N ratios, and hydroxyapatite pikes were calculated. Some deuteriations on the dentin surface were observed in SEM images after 30 Gy and subsequent doses. One-way ANOVA revealed that there was no significant alteration in weight percentages of C, O, Mg, Ca, P, and N between groups. Radiation did not influence stoichiometric Ca/P, Ca/N, and P/N molar ratios. XRD analysis did not show a remarkable decline in hydroxyapatite pikes by the increasing doses. Radiotherapy changes the micromorphology of circumpulpal dentin but does not affect elemental composition and crystallinity.

Morphological patterns of circumpulpal dentin affected by radiation-related caries

BACKGROUND

The aim of this work was to evaluate the microscopic characteristics through polarized light microscopy, scanning electron microscopy and the mineral content of circumpulpal dentin of irradiated (IT) and non-irradiated teeth (NIT), with deep caries that reached the root canal.

MATERIAL AND METHODS

A total of 25 IT were analyzed macroscopically, and radiographed. 5 NIT were used as controls. Two 100-μm-thick sections, per specimen, were evaluated in a polarized light microscopy and a scanning electron microscope. Demographics and clinical data were collected.

RESULTS

The results did not demonstrate distinct morphology of the IT compared with NIT. Mineral content values by weight percentage of Ca and P were also similar, corresponding to 66.65% and 33.21% in the IT and 66.60% and 33.29% in the NIT. The Ca/P ratio did not show statistical differences between groups being respectively 2.74 and 2.72, in the IT and NIT (p> 0.05).

CONCLUSIONS

Radiotherapy does not change morphology and mineral content of circumpulpal dentin in IT. Key words:Root canal, radiation-related caries, polarization microscopy, scanning electron microscopy, radiotherapy, oral neoplasms, dentin.

The Outcome of Primary Root Canal Treatment in Postirradiated Patients: A Case Series

Osteoradionecrosis (ORN) of the jaw is considered the most severe long-term adverse effect that can occur in radiation therapy patients. Teeth extractions and dental diseases are the main risk factors for ORN in irradiated patients. The aim of this case series was to evaluate the outcome of primary root canal treatments performed on patients who underwent head and neck radiotherapy and to evaluate any ORN related to the endodontic treatment. In this case series, primary root canal therapies (absence of radiolucency) were performed on 10 teeth of 8 patients who underwent radiotherapy for head and neck cancers. Radiation doses to the periapical area were calculated using the radiotherapy planning computed tomographic scan. After a 277-day mean follow-up, all patients were asymptomatic, no teeth showed periapical radiolucency, and no ORN was observed. Even if a limitation of buccal opening occurred after radiotherapy and complicated the endodontic procedures, root canal therapy seemed to be safe and a valid alternative to tooth extraction.

Dental Pulp Status of Posterior Teeth in Patients with Oral and Oropharyngeal Cancer Treated with Radiotherapy: 1-year Follow-up

INTRODUCTION

Teeth may react negatively to pulp sensitivity testing in patients who have undergone radiotherapy. The aim of the current investigation was to evaluate the pulp sensibility of posterior teeth at 4, 6, and 12 months in patients who have undergone radiotherapy for oral and oropharyngeal malignancies.

METHODS

Seventy-nine patients diagnosed with malignant oral and oropharyngeal cancer undergoing radiotherapy underwent cold thermal pulp sensitivity testing and electric pulp testing of 4 teeth, 1 from each quadrant. The results were recorded at 5 different time points (TPs): before radiotherapy (TP1), at the end of radiotherapy at 66-70 Gy (TP2), 4 months after the completion of radiotherapy (TP3), 6 months after the completion of radiotherapy (TP4), and 12 months after the completion of radiotherapy (TP5).

RESULTS

All 288 teeth tested positive to cold thermal pulp sensitivity testing and electric pulp testing (EPT) at TP1 (100%). No tooth responded to the cold test (100%) at TP4 and TP5, and progressively higher EPT values were noted during the observation period. A statistically significant difference existed in the number of positive responses between different TPs.

CONCLUSIONS

There was a progressive decrease in pulp sensibility from TP1 to TP5 in teeth of patients with oral and oropharyngeal cancer who underwent radiotherapy (66-70 Gy). No response to cold thermal tests was noted at TP4 (6 months) and TP5 (12 months), and teeth responded at increasingly higher EPT values from TP1 through TP5. This result was statistically significant.

Frequency of persistent tooth pain after root canal therapy: a systematic review and meta-analysis

INTRODUCTION

Little is known about the frequency of persistent pain after endodontic procedures even though pain is a core patient-oriented outcome. We estimated the frequency of persistent pain, regardless of etiology, after endodontic treatment.

METHODS

Persistent tooth pain was defined as pain present > or = 6 months after endodontic treatment. Endodontic procedures included in the review were pulpectomy, nonsurgical root canal treatment, surgical root canal treatment, and retreatment. Four databases were searched electronically complemented by hand searching. Two independent reviewers determined eligibility, abstracted data, and assessed study quality. A summary estimate of persistent all-cause tooth pain frequency was established by using a random-effects meta-analysis. Using subgroup analyses, we explored the influence of treatment approach (surgical/nonsurgical), longitudinal study design (prospective/retrospective), follow-up rate, follow-up duration, initial treatment versus retreatment, and quality of reporting (Strengthening the Reporting of Observational Studies in Epidemiology rankings) on the pain frequency estimate.

RESULTS

Of 770 articles retrieved and reviewed, 26 met inclusion criteria. A total of 5,777 teeth were enrolled, and 2,996 had follow-up information regarding pain status. We identified 168 teeth with pain and derived a frequency of 5.3% (95% confidence interval, 3.5%-7.2%, p < 0.001) for persistent all-cause tooth pain. High and statistically significant heterogeneity among studies (I2 = 80%) was present. In subgroup analysis, prospective studies had a higher pain frequency (7.6%) than retrospectives studies did (0.9%). Quality of study reporting was identified as the most influential reason for study heterogeneity.

CONCLUSIONS

The frequency of all-cause persistent tooth pain after endodontic procedures was estimated to be 5.3%, with higher report quality studies suggesting >7%.

Dental needs in brazilian patients subjected to head and neck radiotherapy

In spite of its recognized benefits in the treatment of malignant tumors, radiation therapy have several side effects in the head and neck region. The evaluation of oral conditions by a dentist is important to prevent or minimize these problems. The aim of this retrospective review was to analyze the dental needs in 357 patients who received radiotherapy in the head and neck region and were treated at Orocentro/FOP/UNICAMP, between January 1990 and December 2004. Review of patient files showed that dental examination before radiotherapy was not performed in 148 patients (41.5%) and was done in 209 patients (58.5%). From the total of examined patients, 94 (45%) did not require dental procedures at the moment of examination, while 115 (55%) presented some sort of dental need. Following the patients after the radiotherapy, it was observed that the group of patients that was evaluated before radiation presented less need of restorations, root canal filling and dental extractions than those who were not evaluated. The results of this study confirm that the evaluation of oral conditions prior to radiotherapy is essential to minimize the dental needs, emphasizing the importance of the dentist in the multidisciplinary team that treats cancer patients.

Outcome of primary root canal treatment: systematic review of the literature - part 1. Effects of study characteristics on probability of success

AIMS

The aims of this study were (i) to conduct a comprehensive systematic review of the literature on the outcome of primary (initial or first time) root canal treatment; (ii) to investigate the influence of some study characteristics on the estimated pooled success rates.

METHODOLOGY

Longitudinal clinical studies investigating outcome of primary root canal treatment, published up to the end of 2002, were identified electronically (MEDLINE and Cochrane database 1966-2002 December, week 4). Four journals (International Endodontic Journal, Journal of Endodontics, Oral Surgery Oral Medicine Oral Pathology Endodontics Radiology and Dental Traumatology & Endodontics), bibliographies of all relevant papers and review articles were hand-searched. Three reviewers (Y-LN, SR and KG) independently assessed, selected the studies based on specified inclusion criteria, and extracted the data onto a pre-designed proforma. The study inclusion criteria were: longitudinal clinical studies investigating root canal treatment outcome; only primary root canal treatment carried out on the teeth studied; sample size given; at least 6-month postoperative review; success based on clinical and/or radiographic criteria (strict, absence of apical radiolucency; loose, reduction in size of radiolucency); overall success rate given or could be calculated from the raw data. The findings by individual study were summarized and the pooled success rates by each potential influencing factor were calculated for this part of the study.

RESULTS

Of the 119 articles identified, 63 studies published from 1922 to 2002, fulfilling the inclusion criteria were selected for the review: six were randomized trials, seven were cohort studies and 48 were retrospective studies. The reported mean success rates ranged from 31% to 96% based on strict criteria or from 60% to 100% based on loose criteria, with substantial heterogeneity in the estimates of pooled success rates. Apart from the radiographic criteria of success, none of the other study characteristics could explain this heterogeneity. Twenty-four factors (patient and operative) had been investigated in various combinations in the studies reviewed. The influence of preoperative pulpal and periapical status of the teeth on treatment outcome were most frequently explored, but the influence of treatment technique was poorly investigated.

CONCLUSIONS

The estimated weighted pooled success rates of treatments completed at least 1 year prior to review, ranged between 68% and 85% when strict criteria were used. The reported success rates had not improved over the last four (or five) decades. The quality of evidence for treatment factors affecting primary root canal treatment outcome is sub-optimal; there was substantial variation in the study-designs. It would be desirable to standardize aspects of study-design, data recording and presentation format of outcome data in the much needed future outcome studies.

Levels of Evidence for the Outcome of Nonsurgical Endodontic Treatment

The purpose of this systematic review was (a) to search for clinical articles pertaining to success and failure of nonsurgical root canal therapy, and (b) to assign levels of evidence to these studies. Electronic and manual searches were conducted to identify studies published between January 1966 and September 2004 with information on the success and failure of nonsurgical root canal therapy. Articles were reviewed and graded for strength of level of evidence (LOE) from one (highest level) to five (lowest level). This review resulted in the identification of 306 clinical studies related to this topic area. Six articles were randomized controlled trials (RCTs, LOE 1). This search also identified 12 low-quality RCTs (LOE 2), 14 cohort studies (LOE 2), five case-control and eight cross sectional studies (LOE 3), four low-quality cohort studies (LOE 4), and five low-quality case-control studies (LOE 4). The majority (73) of the often-quoted "success and failure" studies were case series (LOE 4). The rest of the articles were descriptive epidemiological studies (42), case reports (114), expert opinions (18), literature reviews (4), and one meta-analysis. Based on these findings, it appears that a few high-level studies have been published in the past four decades related to the success and failure of nonsurgical root canal therapy. The data generated by this search can be used in future studies to specifically answer questions and test hypotheses relevant to the outcome of nonsurgical root canal treatment.

Pretherapy dental decisions in patients with head and neck cancer. A proposed model for dental decision support

OBJECTIVE

The proposed model was designed to function as a tool for the development and testing of evidence-based clinical guidelines for the pretherapy oral screening and dental management of patients with head and neck cancer.

STUDY DESIGN

Methods of clinical decision analysis were used to analyze the decision dilemma and construct a decision algorithm and decision tree. The robustness of the model was tested by means of a probabilistic sensitivity analysis with second-order Monte Carlo simulations (n = 10.000).

RESULTS

Clinical criteria for evaluating dental pathologic conditions and malignancy- and patient-related conditions were transformed in probability estimates. The tradeoffs between the benefits and drawbacks of the dental intervention were integrated into the model to identify the optimal option for dental intervention. The calculation process of "folding back and averaging out" the decision tree enabled the identification of the optimal options for dental intervention in four different pretherapy risk conditions.

CONCLUSIONS

A priori testing of the proposed model with 95% confidence intervals suggests that it has a great potential for solving clinical dilemmas associated with pretherapy dental decision-making. In addition, it seems a useful tool for the development of evidence-based clinical guidelines. A posteriori clinical testing should further validate the model before its assimilation into clinical practice takes place.

An evaluation of root canal treatment in patients who have received irradiation to the mandible and maxilla

OBJECTIVE

The purpose of this study was to evaluate the success and failure of root canal treatment performed in areas of previous irradiation and to examine any cases of osteoradionecrosis associated with such treatment.

STUDY DESIGN

A retrospective analysis was done on 22 teeth that had root canal treatment after radiation therapy. Strict radiographic and clinical criteria were used to determine success and failure.

RESULTS

There was a mean follow-up period of 19 months. Of 22 cases, 20 (91%) were considered successful. Both failures occurred with a diagnosis of pulpal necrosis. There were no occurrences of osteoradionecrosis.

CONCLUSIONS

Our study showed that root canal treatment in previously irradiated patients may be successful. In addition, treatment approaches, as well as the criteria for success and failure, should be the same for irradiated patients as for those who have not received radiation treatment.

A direct method for fabricating tongue-shielding stent

During oral cancer radiotherapy, a tongue-shielding radiation stent guides the patient's upper and lower jaws to a repeatable position, attenuates radiation doses, and protects the tongue and structures adjacent to the irradiated field. Conventionally, a tongue-shielding radiation stent is made of heat-cured polymethyl methacrylate resin in which a low-melting Pb-Bi-Sn alloy is embedded as a shielding layer. Its use involves multiple and lengthy clinical and laboratory procedures. An improved polyvinyl siloxane-metal composite shielding system for radioprotection has recently been developed. This two-component, base and catalyst, putty material offers a shielding effect similar to that of the conventional shielding alloys. Its major advantages are that it is simple to use, requires only one clinical appointment, and affords efficient collaboration between dental and medical teams during cancer treatment. This article describes a simplified direct method of fabricating a tongue-shielding stent with the use of a new polyvinylsiloxane-metal composite in conjunction with impression putty material.

Late effects of radiation therapy in the head and neck region

The head and neck region is composed of numerous structures, each with an inherent response to radiation that is largely governed by the presence or absence of mucosa, salivary glands, or specialized organs within that site. Irradiated mucocutaneous tissues demonstrate increased vascular permeability that leads to fibrin deposition, subsequent collagen formation, and eventual fibrosis. Irradiated salivary tissue degenerates after relatively small doses, leading to markedly diminished salivary output. This, in turn, effects the teeth by promoting dental decay which, in turn, effects the integrity of the mandible. Details of these changes are presented, including their pathophysiology, clinical syndromes, and potential treatment.

Management of orofacial pain in cancer patients

Pain in patients with cancer may arise due to the primary disease, or due to therapy of the malignant disease. Pain may be caused by oral infection, oral mucositis, and by alteration in musculoskeletal and neurological function. The management of orofacial and oropharyngeal pain in patients with cancer is reviewed in this paper.