Overview
Secondary dental caries, also known as recurrent caries, refers to the development of new carious lesions at or near the margins of existing restorations. This condition poses significant challenges in dental practice due to its potential to undermine the longevity of dental treatments and compromise tooth integrity. The etiology often involves inadequate restoration margins, microleakage, and insufficient protection against acid challenges from dietary and microbial sources. Understanding the clinical presentation, diagnosis, and management strategies is crucial for effective prevention and treatment. This guideline synthesizes evidence from various studies to provide clinicians with a comprehensive approach to addressing secondary dental caries.
Clinical Presentation
Secondary dental caries can manifest in several clinical forms, often presenting as localized pain, sensitivity, discoloration, or visible cavitation around existing restorations. One notable risk factor highlighted by a study involving discovery® brackets and Transbond XT adhesive [PMID:27896419] is the increased incidence of enamel fracture, observed in 11 out of 15 specimens. This suggests that certain orthodontic materials may predispose teeth to structural weaknesses, potentially facilitating secondary caries development. Clinicians should be vigilant when using these materials and consider additional protective measures to mitigate such risks.
Postoperative sensitivity following restoration of carious teeth with silver amalgam is another common presentation, as emphasized by research [PMID:20660970]. This sensitivity underscores the importance of employing effective cavity liners to protect the remaining tooth structure from further demineralization and to enhance patient comfort. Effective liners not only reduce sensitivity but also act as a barrier against microleakage, thereby reducing the risk of secondary caries.
Diagnosis
Diagnosing secondary dental caries requires a thorough clinical examination complemented by appropriate diagnostic tools. The Adhesive Remnant Index (ARI) has emerged as a useful diagnostic tool in evaluating bond quality, particularly in orthodontic contexts [PMID:27896419]. Studies have shown predominantly low ARI scores (0 or 1) across various adhesive-bracket combinations, indicating potential issues with bond integrity that could predispose teeth to secondary caries. Clinicians should routinely assess ARI scores to identify compromised restorations early.
Saliva contamination significantly impacts the bond strength of restorative materials, as demonstrated by research [PMID:12450709]. The substantial decrease in glass-ionomer cement (GIC) bond strength from 2.46 MPa to 1.28 MPa underscores the necessity for meticulous oral hygiene practices and contamination control during both diagnosis and treatment phases. Ensuring clean surfaces before bonding procedures is critical to achieving durable restorations and preventing secondary caries.
Management
Preventive Measures
Preventing secondary dental caries involves multiple strategies, including the use of protective materials and optimizing restorative techniques. Resin-type tooth-coating materials, particularly those containing S-PRG filler such as BC17 and BC33, have shown promise in reducing demineralization depths [PMID:28120171]. These materials can effectively shield dentin from acid attacks, thereby mitigating the risk of secondary caries. Clinicians should consider these advanced materials for patients at high risk of recurrent caries.
The choice of restorative material also plays a crucial role. While resin-based adhesives like BC, HC, and SF exhibit high shear bond strengths to dentin, glass-ionomer materials like FJ demonstrate superior resistance to demineralization post-shear bond strength (SBS) testing [PMID:28120171]. This dual advantage makes glass-ionomer cements particularly valuable in clinical settings where both bond strength and long-term protection against caries are essential.
Bonding and Restoration Techniques
Effective bonding techniques are paramount in preventing secondary caries. In vitro studies have shown that certain adhesive systems perform well under various conditions. For instance, Transbond™ XT yielded the highest SBS values when combined with metal and ceramic brackets [PMID:27896419]. Clinicians should select adhesives known for their robust bonding capabilities, especially in high-stress areas prone to microleakage.
However, the impact of external factors such as whitening treatments cannot be overlooked. Treatment with higher concentrations of hydrogen peroxide (9.5% and 10%) significantly diminishes composite resin bond strength [PMID:26067726]. To mitigate this, clinicians might consider using fluoride-supplemented whitening gels or limiting the duration and frequency of whitening treatments in patients with recent restorations. Conversely, enamel treated with a 7.5% hydrogen peroxide gel enriched with fluoride, calcium, and potassium nitrate showed enhanced bond strength, suggesting a balanced approach to whitening and restoration maintenance [PMID:26067726].
Managing Sensitivity and Contamination
Postoperative sensitivity remains a common issue post-restoration, particularly with amalgam fillings. Studies indicate that 2% sodium fluoride (NaF) iontophoresis can significantly reduce sensitivity compared to traditional varnish and adhesive liners [PMID:20660970]. This non-invasive method offers a viable option for managing sensitivity, thereby improving patient compliance and comfort.
Contamination, whether from saliva or blood, poses significant challenges to bond strength. Research has shown that air drying, application of maleic acid, or using Scotchbond primer can restore tensile bond strength in saliva-contaminated enamel [PMID:12450709]. Similarly, blood contamination did not affect the bond strength of Fuji Ortho LC when proper enamel conditioners were used [PMID:15592219]. Clinicians should employ appropriate enamel conditioners like self-etching primers and phosphoric acid to ensure optimal bond strength even under contaminated conditions.
Material Selection and Application
The selection of restorative materials should consider both bond strength and resistance to demineralization. In vitro studies comparing various one-bottle adhesives found that Prime & Bond 2.1 provided clinically acceptable bond strengths [PMID:10530273], making it a reliable choice for managing secondary caries. However, glass-ionomer cements (GICs) generally exhibit lower bond strengths compared to composite resins [PMID:1840104]. Adjusting the powder/liquid ratio can significantly enhance bond strength for certain GICs, such as Intact and Orthocem B, highlighting the importance of proper mixing techniques to ensure clinical success and reduce secondary caries risk.
Key Recommendations
By integrating these evidence-based practices, clinicians can significantly reduce the incidence and impact of secondary dental caries, thereby improving patient outcomes and restorative longevity.
References
1 Arita S, Suzuki M, Kazama-Koide M, Shinkai K. Shear bond strengths of tooth coating materials including the experimental materials contained various amounts of multi-ion releasing fillers and their effects for preventing dentin demineralization. Odontology 2017. link 2 Hofmann E, Elsner L, Hirschfelder U, Ebert T, Hanke S. Effects of enamel sealing on shear bond strength and the adhesive remnant index : Study of three fluoride-releasing adhesives in combination with metal and ceramic brackets. Journal of orofacial orthopedics = Fortschritte der Kieferorthopadie : Organ/official journal Deutsche Gesellschaft fur Kieferorthopadie 2017. link 3 Firoozmand LM, Reis WL, Vieira MA, Nunes AG, Tavarez RR, Tonetto MR et al.. Can Whitening Strips interfere with the Bond Strength of Composite Resins?. The journal of contemporary dental practice 2015. link 4 Gupta M, Pandit IK, Srivastava N, Gugnani N. Comparative evaluation of 2% sodium fluoride iontophoresis and other cavity liners beneath silver amalgam restorations. Journal of the Indian Society of Pedodontics and Preventive Dentistry 2010. link 5 Cacciafesta V, Sfondrini MF, Scribante A, De Angelis M, Klersy C. Effect of blood contamination on shear bond strength of brackets bonded with a self-etching primer combined with a resin-modified glass ionomer. American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 2004. link 6 Chen CN, Huang GF, Guo MK, Lin CP. An in vitro study on restoring bond strength of a GIC to saliva contaminated enamel under unrinse condition. Journal of dentistry 2002. link00019-2) 7 Swift EJ, Perdigão J, Heymann HO, Ritter AV. Shear bond strengths of one-bottle adhesives to moist enamel. Journal of esthetic dentistry 1999. link 8 Evans R, Oliver R. Orthodontic bonding using glass ionomer cement: an in vitro study. European journal of orthodontics 1991. link
8 papers cited of 12 indexed.