ReviewClinical performance of cervical restorations—A meta-analysis
Introduction
About a quarter of the population do have non-carious cervical lesions, and the lesions are significantly more prevalent at older ages (<50%), with premolars being the most affected teeth [1]. There is consensus that the etiology is multifactorial with mechanical-abrasive (toothbrush/toothpaste) and erosive (acids from food and beverages) processes. Occlusal overloading and/or eccentric movements may be found as co-factors because of some confounding effects, but are unlikely causal factors [2]. There is no biological reason to restore non-carious lesions other than esthetics. Under some circumstances, when the lesion has significantly compromised tooth structure or is progressing at a fast rate, can restoring the lesion prevent further tooth damage. A questionnaire conducted among US general practitioners in the 90s revealed that more than half of the dentists interviewed did not restore non-carious cervical lesions [3].
Loss of retention and marginal discoloration are still the main shortcomings of cervical restorations (Class V) placed with adhesive technology [1], [4]. Both clinical incidents compromise the esthetic appearance, especially if they occur in anterior teeth. The prevalence of retention loss rises sharply with increasing observation periods [5]. On the other hand, Class V non-carious non-retentive lesions are frequently used to clinically evaluate the effectiveness of adhesive systems.
In non-carious cervical lesions, restoratives are placed with either preparation of dentin and/or enamel. In contrast to intact or caries-affected dentin, non-carious cervical lesions exhibit a high degree of sclerosis and have a high amount of minerals, which renders the establishment of a hybrid layer more difficult [6]. Some clinicians roughen the dentin and enamel with a diamond bur and/or bevel the enamel margin to improve the bond to the hard tissues. The results of some clinical studies on the topic of preparation are inconclusive [7]. The influence of absolute versus relative isolation of the treatment field is another topic that is subject to controversy. A meta-analysis revealed no influence of the type of isolation on the survival rate in posterior composite restorations [8]. A systematic analysis of clinical studies on cervical restorations has, to date, not been carried to investigate these operative aspects.
The type of adhesive system and/or the belonging to a specific class of adhesives as proposed by Van Meerbeek [6] may play an important role on the longevity of the restoration. A review of clinical trials on the effectiveness of adhesive systems in non-carious cervical lesions measured as retention loss arrived at the conclusion that glass ionomer cements had the lowest rate of retention loss and 1-step self-etching adhesives the highest [4].
The American Dental Association (ADA) previously defined an adhesive system to be adequate and acceptable for clinical use (“full acceptance”) if the retention rate of restorations placed in non-carious lesions is higher than 90% after an observation period of 1.5 years [9]. Many of the newer adhesive systems, especially the 1-step self-etching systems, would not have received ADA acceptance. The ADA acceptance program was abandoned by the end of 2008 [10].
The goal of the present study was to assess the influence of the following factors on the clinical outcome:
- -
operative technique: beveling of enamel, preparation/roughening of dentin/enamel, absolute versus relative isolation;
- -
the type of adhesive system and/or restorative material;
- -
observation period.
The following hypotheses were examined:
- 1.
Beveling of enamel and/or preparation/roughening of dentin/enamel results in less retention loss and marginal discoloration.
- 2.
The type of isolation does not influence the clinical outcome.
- 3.
The type of adhesive system or restorative material has an influence on the performance of cervical restorations.
Section snippets
Selection of clinical trials on Class V restorations
Prospective clinical studies on Class V restorations were searched in MEDLINE (search period 12/2008) and IADR abstracts (1994–2008). The search words were “Class V” or “cervical” or “abfraction lesion” and “clinical”. The inclusion criteria were as follows:
- 1.
Prospective clinical trial involving at least one adhesive system in Class V cavities.
- 2.
Minimal duration of 18 months.
- 3.
The study had to report about the following outcome variables: retention, marginal discoloration, marginal integrity,
Results
Clinical data from 50 studies have been included in the systematic review (see Appendix A) containing 105 in vivo experiments with 40 different adhesives, 39 different composites, and 63 different combinations adhesives/composites. The type of adhesive and composite/restorative material is listed in the table of the Appendix A. The clinical index could be calculated for 67 experiments at 12 months, 25 at 18 months, 76 at 24 months and 35 at 36 months. Overall, only 14/203 = 7% of the values were
Discussion
The rationale for creating a clinical index is that a better statistical analysis can be carried out. The same index has been used in another study when in vitro and in vivo data on adhesive systems had been compared [11]. The weighing of the three outcome variables was based on the following considerations: (1) Retention loss is the most obvious sign of failure of a cervical restoration and is the most reliable diagnostic evaluation criterion with little variability between different
References (20)
- et al.
Non-carious cervical tooth surface loss: a literature review
J Dent
(2008) - et al.
How dentists classified and treated non-carious cervical lesions
J Am Dent Assoc
(1993) - et al.
Clinical effectiveness of contemporary adhesives: a systematic review of current clinical trials
Dent Mater
(2005) Clinical evaluation of three adhesive systems in class V non-carious lesions
Dent Mater
(2000)- et al.
Marginal adaptation in vitro and clinical outcome of Class V restorations
Dent Mater
(2009) Clinical evaluation of four dentin bonding agents in Class V abrasion lesions: a four-year follow-up
Dent Mater
(1994)- et al.
Abfraction: separating fact from fiction
Aust Dent J
(2009) - et al.
Clinical long-term retention of etch-and-rinse and self-etch adhesive systems in non-carious cervical lesions. A 13 years evaluation
Dent Mater
(2007) - et al.
Buonocore memorial lecture. Adhesion to enamel and dentin: current status and future challenges
Oper Dent
(2003) - et al.
Longevity of direct resin composite restorations in posterior teeth
Clin Oral Investig
(2003)
Cited by (129)
A qualitative analysis of dentists’ understanding and management of non-carious cervical lesions (NCCL)
2023, Journal of DentistryClinical and OCT assessment of application modes of a universal adhesive in a 12-month RCT
2022, Journal of Dentistry