How strong is the evidence for the need to restore posterior bounded edentulous spaces in adults? Grading the quality of evidence and the strength of recommendations

Adjacent tooth migration after maxillary first molar loss in patients with sinus augmentation: A retrospective research

PURPOSE

The objectives of this study are to: (1) investigate the extent of antagonistic and distal neighboring tooth migration in the maxillary posterior single tooth-missing site during the healing period of bone augmentation and implant surgery; (2) identify factors associated with tooth migration.

MATERIALS AND METHODS

One hundred and forty-three cases that lost the maxillary first molar were included, and their CBCT data during the edentulous period were obtained. Dentition models were reconstructed from CBCT, and superimpositions were performed, followed by measuring migration distances and calculating migration rates of antagonistic and distal neighboring teeth. Factors were analyzed using multivariate generalized estimating equations (GEE).

RESULTS

The mean migration distances were 208 ± 137 μm and 403 ± 605 μm for antagonistic teeth and distal teeth, and the mean migration rates were 26.8 ± 21.2 μm/month and 48.5 ± 76.7 μm/month, respectively. One hundred and nineteen out of 143 distal neighboring teeth migrated toward the edentulous site, and all antagonistic teeth migrated occlusally. Occlusal contact loss and chronic apical periodontitis both significantly accelerated antagonistic tooth migration (p < 0.05), the latter also accelerated distal tooth migration (p < 0.05). Besides, the displacement of the distal teeth was somewhat accelerated by the impacted adjacent third molar and root protrusion into the sinus.

CONCLUSIONS

The neighboring teeth tend to migrate toward the edentulous gap in the maxillary posterior region. Occlusal contact loss and chronic apical periodontitis are two significant risk factors for accelerating antagonistic tooth migration, and for distal teeth, chronic apical periodontitis is the risk factor. The impacted adjacent third molar and root protrusion into the sinus are also potential risk factors for accelerating the migration of the maxillary distal tooth. Thus, to prevent maxillary edentulous gap reduction, the factors mentioned above should be taken into consideration when planning treatment flow.

Three-dimensional position changes of unopposed molars before implant rehabilitation: a short-term retrospective cohort analysis

OBJECTIVE

To investigate the spatial changes of unopposed molars within the period between the antagonist extraction and the final implant restoration using data from cone beam computed tomography.

METHODS

A total of 59 patients with 68 unopposed molars were included in this study. Three-dimensional models reconstructed from cone beam computed tomography data before and after loss of the antagonist were superimposed to measure the spatial changes. The overeruption and tipping of target teeth were calculated by coordinate values.

RESULTS

The result of overeruption over the study period (9.2 ± 4.3 months) was expressed by two values: the mean overeruption of molar cups (0.432 mm) and the maximum overeruption of cusps (0.753 mm), which were statistically significant compared to the baseline level (p < 0.001). The average tipping was 1.717 degrees in the buccal direction.

CONCLUSIONS

Unopposed molars displayed overeruption throughout the study period (9.2 ± 4.3 months), which indicates that the clinicians should pay attention to the possibilities of overeruption and make appropriate interventions in their clinical practice. The establishment of three-dimensional measuring methods using cone beam computed tomography data helps analyze spatial changes.

[Three-dimensional movement of posterior teeth after losing the interproximal and occlusal contacts in adults]

OBJECTIVE

To observe the movement of posterior teeth after losing the interproximal and occlusal contacts in adults from the amount and speed of mesial-distal, buccal-lingual, occlusal-gingival and three-dimensional movements.

METHODS

Twenty cases of metal post-core restoration from the Department of Prosthodontics, Peking University School and Hospital of Stomatology were recruited into this study, which was an observational study. The restored teeth had complete mesial, distal, and occlusal contacts before treatment. All the interproximal and occlusal contacts were removed during the preparation for the post-core. The three-dimensional positions of the post-core preparation were obtained by the intraoral scanner at the day of tooth preparation and that of post-core placement. The amounts of mesial-distal, buccal-lingual and occlusal-gingival tooth movement were measured in the software. On this basis, the amount of three-dimensional tooth movement was calculated. The speed of tooth movement was calculated based on the elapsed time between the two scans.

RESULTS

Ten females and ten males with an average age of (29.5±4.9) years were recruited. The average elapsed time was (10.9±2.7) days. The amount of the mesial-distal tooth movement was (134.8±61.2) μm, of the buccal-lingual tooth movement was (110.3±39.5) μm, of the occlusal-gingival tooth movement was (104.8±57.5) μm, and of the three-dimensional tooth movement was (211.4±71.0) μm, respectively. The amounts of mesial-distal, buccal-lingual and three-dimensional tooth movements were larger in female than in male (P < 0.05). The speed of the mesial-distal tooth movement was (13.1±7.8) μm/d, of the buccal-lingual tooth movement was (10.6±4.5) μm/d, of the occlusal-gingival tooth movement was (10.1±6.8) μm/d, and of the three-dimensional tooth movement was (20.5±9.7) μm/d, respectively. The speed of mesial-distal and buccal-lingual tooth movements were larger in female than in male (P < 0.05). The speed of three-dimensional tooth movement was slightly larger in female than in male, while there was no significant difference between different genders (P>0.05).

CONCLUSION

The three-dimensional position of posterior teeth changed after losing the interproximal and occlusal contacts in adults. The female had more significant and faster tooth movement than the male.

Variation in dental occlusal schemes two years after placement of single-implant posterior crowns. A preliminary study

Some authors have recommended that implant-supported single crowns should only contact during heavy clenching. However, a lack of occlusal contact with moderate clenching may cause supra-eruption of antagonist natural teeth. The main objective of this study was to assess changes in the occlusal contacts of posterior implant-supported single crowns with natural antagonist teeth two years after placement. The occlusal schemes of 14 patients who received 16 implant-supported single crowns in molar and premolar regions were assessed in this prospective study. Just after crown placement, at 6 months and after 2 years a silicone maxillomandibular relationship and T-scan records were obtained during the intercuspal position with light and heavy clenching, determined using near half of the maximum force and maximum force respectively. Occlusal contacts were assessed quantitatively and qualitatively in the implant-supported single crowns, contralateral tooth and adjacent tooth; the latter two were used as controls. After six months and two years, no significant variations were observed in any region of the occlusal scheme in any assessments, including silicone record or T-Scan, using light or heavy clenching, and qualitative or quantitative occlusal contact assessment. In this preliminary study, the occlusal scheme did not vary at the intercuspal position two years after placing posterior implant-supported single crowns.

Patients' Values in Clinical Decision-Making

OBJECTIVE

Shared decision-making involves the participation of patient and dental practitioner. Well-informed decision-making requires that both parties understand important concepts that may influence the decision. This fourth article in a series of 4 aims to discuss the importance of patients' values when a clinical decision is made.

METHODS

We report on how to incorporate important concepts for well-informed, shared decision-making. Here, we present patient values as an important issue, in addition to previously established topics such as the risk of bias of a study, cost-effectiveness of treatment approaches, and a comparison of therapeutic benefit with potential side effects.

RESULTS

We provide 2 clinical examples and suggestions for a decision tree, based on the available evidence.

CONCLUSION

The information reported in this article may improve the relationship between patient and dental practitioner, resulting in more well-informed clinical decisions.

Evaluating benefits and harm of therapies

OBJECTIVE

This third article in a series of 4 aims to inform dental practitioners on the importance of weighing benefits and harm when making clinical treatment decisions.

METHODS

This article describes some examples of important consequences to patients' health when potential side effects of interventions are not taken into consideration in the decision-making process. Some information to help dental practitioners search for data on negative effects of therapies is also presented, and the need to weigh benefits and harm of therapies is discussed.

RESULTS

Therapeutic interventions in dentistry may cause several side effects, such as nerve damage caused by dental implant placement. Adequate evaluation of potential side effects before performing a procedure and comprehensive communication with the patient about these side effects are sine qua non conditions for any clinical decision.

CONCLUSIONS

The information provided in this article may encourage dental practitioners to obtain more information regarding negative aspects of clinical interventions, to more comprehensively inform patients and to improve clinical decision-making.

Professional Variability in Decision Making in Modern Dentistry: A Pilot Study

Dental treatment planning is usually expected to take account of the individual patient's clinical risks and benefits. Ideally, the therapeutic choice for each and every patient should be based on adequate clinical diagnostics and risk assessment that facilitates stabilization of the patient's clinical condition as well as prevents further oral impairment. However, identification of the most suitable approach tends to become more and more challenging as the number of therapeutic alternatives continues to increase due to medical innovation. In this study, the challenge of decision making in modern dentistry is illustrated using the example of bounded edentulous spaces. Many therapeutic alternatives exist for such clinical scenarios, including a noninvasive monitoring approach, minimally invasive tooth recontouring, orthodontic and prosthodontic treatment, and implant placement. The findings of this pilot study highlight the utmost relevance of incorporating individual patients' needs and risks into clinical treatment planning and providing appropriate guidelines.

The clinical prognosis of implants that are placed against super-erupted opposing dentition

OBJECTIVES

If teeth are missing, super-eruption of teeth in the opposing arch can occur in the area and can change the occlusal plane. When missing teeth are replaced with implants, the oral surgeon must determine whether or not the super-erupted teeth need to be treated in order to normalize the occlusal plane. In this study, we evaluated the clinical prognosis of dentition after implant placement and prosthetic treatment were completed in an occlusal plane altered by super-erupted teeth in the opposing arch without additional treatment of the super-erupted teeth.

MATERIALS AND METHODS

Twenty-two patients (9 males, 13 females) were treated with implants and prosthetics without addressing the super-erupted opposing dentition from April 2004 to August 2012 at Seoul National University Bundang Hospital. A total of 33 implants were placed. Values of crestal bone loss, survival rates, and surgical and prosthetic complications for an average of 29.6 months after prosthetic loading were recorded.

RESULTS

In one case, the cover screw was exposed after implant surgery. The mean crestal bone loss was 0.09±0.30 mm. Of the 33 implants, 31 survived, a survival rate of 93.94%. A prosthetic complication occurred in one case but functioned well after correction.

CONCLUSION

Favorable clinical results from prosthetic complications, crestal bone loss, and implant survival rates were exhibited in implants next to a super-erupted opposing tooth.

Does fixed retention prevent overeruption of unopposed mandibular second molars in maxillary first molar extraction cases?

Background

The objective of this study was to investigate whether multistranded fixed retainers prevented overeruption of unopposed mandibular second molars in maxillary first molar extraction cases.

Methods

The panoramic radiographs of 65 Class II Division 1 Caucasian Whites (28 females, 37 males) consecutively treated with bilateral maxillary first molar extraction and the Begg technique, and with records taken after treatment (T1) and in retention (T2), were withdrawn from private practice records. After appliance removal, mandibular second molars were retained with sectional wires till at least T2 in case of lack of occlusal contact with the antagonist. The subjects were assigned to study-retention and control-nonretention groups based on the retention status of mandibular second molars. Radiographic analysis was carried out to determine inclination of mandibular molars and the resulting movement of second molar centroids. Parametric and nonparametric tests were performed to assess the changes between T1 and T2.

Results

No statistically significant differences in molar inclination were observed between groups and timepoints (P > 0.05). There were no statistically significant differences in molar movement percentages (P > 0.05) irrespective of whether fixed retention had been used or not.

Conclusions

No significant eruption occurred in unopposed mandibular second molars bonded with fixed sectional retainers compared to molars partially occluded with the antagonists without fixed retention. Given the study limitations, fixed retention should be considered with caution in restricting tooth overeruption in unopposed molars.

A comparison of tooth retention and replacement across 15 countries in the over-50s

OBJECTIVES

Oral diseases are still among the most common chronic diseases globally with substantial detrimental impact especially on elderly people's health and well-being. However, limited evidence exists on international variation in the oral health status of the older population. We aimed to examine international variation in tooth loss and tooth replacement in the general population aged between 50 and 90 years.

METHODS

A cross-sectional analysis of data from the fifth wave of the Survey of Health, Ageing and Retirement in Europe (SHARE) was conducted. The data cover 14 European countries (Austria, Belgium, Czech Republic, Denmark, Estonia, France, Germany, Italy, Luxembourg, the Netherlands, Slovenia, Spain, Sweden, and Switzerland) and Israel, and they were collected during the year 2013. Age-specific percentages of the population having all natural teeth, the age-specific numbers of natural (and artificial) teeth, and the age-specific percentages of full, partial, or no replacement of missing teeth were assessed with stratification by country. It was further evaluated to which extent proposed oral health goals concerning tooth loss at higher ages had been achieved.

RESULTS

In total, 62,763 individuals were included in the study. Age-standardized mean numbers of natural teeth exhibited substantial variation, ranging from 14.3 (Estonia) to 24.5 (Sweden). The oral health goal of retaining at least 20 teeth at age 80 years was achieved by 25% of the population or less in most countries. A target concerning edentulism (≤15% in population aged 65-74 years) was reached in Sweden, Switzerland, Denmark, France, and Germany. Tooth replacement practices varied especially for a number of up to five missing teeth which were more likely to be replaced in Austria, Germany, Luxembourg, and Switzerland than in Israel, Denmark, Estonia, Spain, and Sweden.

CONCLUSIONS

This study suggests that the age-specific number of natural teeth and the practice of tooth replacement in the over 50s differ substantially among the included countries. The present results may be helpful in the formulation and evaluation of oral health goals in the older population.

Exploring motivations to seek and undergo prosthodontic care: a cross-sectional study in a Brazilian adult sample

This study explored the influence of individual and social factors regarding intentions and behaviors related to prosthodontic treatment, using the theory of planned behavior (TPB). A cross-sectional study was designed with a sample of 225 individuals with some degree of tooth loss. A questionnaire was used containing factors that would have potential influence on the intentions and behaviors of individuals, as well as clinical and sociodemographic data. Descriptive statistics, internal consistency analysis, chi-square test for trend, and logistic regression were used for data analysis. The TPB components - attitude toward the behavior (ATB), subjective norm (SN), and perceived behavioral control (PBC) - showed good internal consistency (alpha = 0.60-0.78). Intention and behavior were associated with TPB components and the overall scale. Similarly, positive intentions and behaviors were associated with age, upper tooth loss, anterior tooth loss, and higher social status. Multiple logistic regression showed that intention was associated with PBC (OR =1.57; P<0.016), while behavior was associated with tooth loss in both arches (OR =9.3; P<0.001), anterior tooth loss (OR =5.13; P<0.001), higher social status (OR =3.06; P<0.03), and PBC (OR =1.38; P=0.03). The presence of anterior tooth loss was the most relevant factor for prosthodontic treatment demand and utilization, while socioeconomic status and an individual's perceived ease or difficulty in undergoing treatment played a significant, but secondary, role in behavior toward prosthodontic care.

Self-perceived changes in oral health-related quality of life after receiving different types of conventional prosthetic treatments: a cohort follow-up study

OBJECTIVES

To evaluate the changes in oral health-related quality of life (OHRQoL) reported by subjects treated with conventional prostheses.

METHODS

A consecutive sample of 153 patients seeking prosthodontic rehabilitation was recruited. Socio-demographic and prosthetic-related factors (Eichner Index; number of occlusal, aesthetic, and lost units) were registered. Baseline impacts on OHRQoL were collected using the OHIP-14 questionnaire. One month after treatment, the participants answered whether the prostheses had generated better, equal, or poorer effects within the 14 items of a retrospective scale (Post-OHIP). The study patients were compared with the reference population (P-population; n=123) in terms of OHRQoL. Such P-population consisted of Spanish adults wearing conventional dental prostheses who were not seeking any dental treatment. The reliability and validity of the tests applied and the factor structure of the Post-OHIP were investigated. A Poisson regression model was calculated to predict what items would change favourably after treatment.

RESULTS

Four prosthetic cohorts were established according to the types of rehabilitations performed: 1-FDPs: metal-ceramic fixed dental prostheses; 2-M-RPDs: metal-based removable partial dentures; 3-ADs: acrylic partial dentures and 4-CDs: complete dentures. Both tests confirmed adequate psychometric properties. Most items of the Post-OHIP consistently loaded on a single factor. Patients requiring ADs or CDs reported significantly lower baseline OHRQoL than those needing M-RPDs or FDPs. Pain/discomfort was the only hampering issue subsequent to removable rehabilitation. M-RPDs are expected to provide the significantly highest therapeutic improvements.

CONCLUSIONS

Patients perceived benefits in chewing ability, aesthetics and satisfaction with their mouth after receiving conventional dental prostheses.

CLINICAL SIGNIFICANCE

Conventional prosthetic therapy enhances patients' overall well-being although it can cause discomfort and chewing dysfunction in more than 20% of subjects. Metal-based removable partial dentures are the most predictable in terms of patient satisfaction. The higher the clinical impairment felt by patients, the higher the increase in OHRQoL after rehabilitation.

Large-scale clinical endodontic research in the National Dental Practice-Based Research Network: study overview and methods

INTRODUCTION

This article reports on the feasibility of conducting a large-scale endodontic prospective cohort study in The National Dental Practice-Based Research Network. This study was designed to measure pain and burden associated with initial orthograde root canal therapy (RCT) and to explore potential prognostic factors for pain outcomes. The main objectives of this first report in a series are to describe the project's feasibility and methods and the demographics of the sample obtained.

METHODS

Sixty-two dentist practitioner-investigators (ie, 46 generalists and 16 endodontists) in 5 geographic areas were certified within the network and trained regarding the standardized study protocol. Enrollment and baseline data collection occurred over 6 months with postobturation follow-up for another 6 months. Patients and dentists completed questionnaires before and immediately after treatment visits. Patients also completed questionnaires at 1 week, 3 months, and 6 months after obturation.

RESULTS

Enrollment exceeded target expectations, with 708 eligible patient-participants. Questionnaire return rates were good, ranging between 90% and 100%. Patient demographics were typical of persons who receive RCT in the United States (ie, mean age = 48 years [standard deviation = 13 years], with most being female [59%], college educated [81%], white non-Hispanic [86%], and having dental insurance [81%]). The tooth types being treated were also typical (ie, 61% molars, 28% premolars, and 11% anteriors, with maxillary teeth being predominant [59%]).

CONCLUSIONS

This study shows the feasibility of conducting large-scale endodontic prospective cohort studies in the network. Patients were rapidly recruited with high levels of compliance in data collection.

Effects of different implant-abutment connections on micromotion and stress distribution: prediction of microgap formation

OBJECTIVES

The aim of this study was to analyse micromotion and stress distribution at the connections of implants and four types of abutments: internal hexagonal, internal octagonal, internal conical and trilobe.

METHODS

A three dimensional (3D) model of the left posterior mandible was reconstructed from medical datasets. Four dental implant systems were designed and analysed independently in a virtual simulation of a first molar replacement. Material properties, contact properties, physiological loading and boundary conditions were assigned to the 3D model. Statistical analysis was performed using one-way analysis of variance (ANOVA) with a 95% confidence interval and Tukey's Honestly Significant Difference (HSD) multiple comparison test.

RESULTS

The internal hexagonal and octagonal abutments produced similar patterns of micromotion and stress distribution due to their regular polygonal design. The internal conical abutment produced the highest magnitude of micromotion, whereas the trilobe connection showed the lowest magnitude of micromotion due to its polygonal profile.

CONCLUSIONS

Non-cylindrical abutments provided a stable locking mechanism that reduced micromotion, and therefore reduced the occurrence of microgaps. However, stress tends to concentrate at the vertices of abutments, which could lead to microfractures and subsequent microgap formation.

The shortened dental arch revisited: from evidence to recommendations by the use of the GRADE approach

Clinicians must frequently decide whether or not to treat patients with loss of posterior teeth, a condition called the shortened dental arch (SDA). Although many studies have been reported, there are no clear recommendations for the management of SDA cases. In this work, therefore, an innovative system, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, was used to grade the evidence and strength of recommendations for clinical intervention. An extensive literature search for longitudinal studies was conducted on 17 November 2010 in the PubMed and LILACS electronic databases using the term shortened dental arch. A 'snowballing' strategy, for example, manual searching of the reference lists of included papers, was also conducted. Unpublished and published studies were sought in ClinicalTrials.gov and in the search engine 'Google' (Scholar) in English, French, German, Italian, Portuguese and Spanish. Finally, grey literature was searched in OpenSIGLE (System for Information on Grey Literature in Europe). Titles and abstracts of 133 articles were initially assessed. Nine studies were finally included. Although there was no difference between the effectiveness of restorative and non-restorative approaches for SDA, fixed partial dentures seem better than removable prostheses. The overall body of evidence was, however, graded as low quality. Two different clinical scenarios are used to illustrate recommendations in the management of SDA cases by the use of the GRADE system. The GRADE approach may improve transparency in a shared decision-making process, mainly under conditions in which the quality of evidence is low or unclear.