Early caries confined to the enamel layer represent a critical window for achieving noninvasive intervention in caries management. Caries management has shifted from the traditional “drill-and-fill” model toward a modern paradigm centered on caries risk and lesion management. Based on contemporary concepts, this review systematically summarizes recent advances in early caries management, including caries risk assessment, early diagnosis, treatment strategy selection, and follow-up monitoring, while highlighting the major challenges currently being faced, and further reviewing and discussing the application of artificial intelligence (AI) in early caries management. In terms of risk management, conventional systems including the American Dental Association, Caries Management by Risk Assessment, Cariogram, and the Caries-Risk Assessment Tool remain mainstays in clinical practice. However, AI offers predictive capability through higher-dimensional data processing and the integration of numerous influencing factors, with the potential to improve the accuracy of risk stratification. For diagnosis, visual inspection, tactile examination, and bitewing radiography remain fundamental methods, yet their sensitivity for early caries—particularly proximal lesions—is limited. The application of optical technologies, including quantitative light-induced fluorescence, optical coherence tomography, near-infrared light transillumination, fiber-optic transillumination, and laser-induced fluorescence, enables digital characterization of caries lesions, providing a data foundation for demineralization assessment, lesion activity evaluation, and AI model development. The management of early caries primarily relies on noninvasive and minimally invasive approaches. Remineralization therapy is suitable for superficial lesions, resin infiltration offers the dual advantages of inhibiting lesion progression and improving aesthetics, and microabrasion and bleaching may serve as adjunctive aesthetic treatments. Emerging modalities such as laser, ozone, and photodynamic therapy have also demonstrated potential. Treatment decision-making should comprehensively consider lesion activity, patient caries risk status, demineralization depth, patient compliance, and treatment preferences. However, precise quantification of demineralization depth remains challenging, and standardized decision-making criteria are still lacking. Follow-up management should be individualized based on risk stratification, with attention to lesion changes, patient compliance, and the risk of recurrence. In summary, intelligent and precision-based approaches are expected to define the future of early caries management, and the application of AI in risk prediction, image analysis, and clinical decision support is anticipated to further enhance the efficiency and effectiveness of early caries diagnosis and treatment.

Microorganisms are closely related to the occurrence and development of common oral diseases. Due to the unique physiological and anatomical characteristics of the oral cavity, locally introduced antibacterial drugs cannot be maintained in the effective concentration range under the effect of saliva erosion. Therefore, to enhance the retention and bioavailability of antibacterial drugs in biofilms, some scholars designed pH sensitive drug delivery systems with the fact that the pH value of oral biofilm is lower than the physiological pH value. This article reviews the research reports of a pH-sensitive drug delivery system in the oral cavity and elaborates its application in oral diseases such as dental caries, endodontic disease, periapical disease, peri-implant diseases, and oral candidiasis. Literature review results show that the pH-sensitive drug delivery system loaded with antibacterial drugs could be used for the control of oral microorganisms with excellent pH sensitivity and antibacterial properties, especially in the application of acid-producing bacteria such as Streptococcus mutans for the prevention and treatment of dental caries. However, the research of pH-sensitive drug delivery systems in the oral cavity is still limited to basic research,and in clinical applications, it still faces many challenges, such as a complex design and synthesis, difficulties with lasting effects and eliminating drug-resistance and persistent bacteria. Further optimization of pH sensitive systems, as well as animal experiments and in vivo studies will be the focus of future research.

Reducing the adhesion of microorganisms and the formation of biofilms on implant surfaces can prevent peri-implant inflammation and optimize the long-term prognosis of implanted dentures. To provide theoretical support for the development of new materials or the modification of existing materials and the improvement of the success rate of implant repair, a literature review was conducted, which shows that the factors influencing bacterial adhesion on dental implant surfaces included the type of implant material, material roughness, nonspecific physical and chemical properties, the type of antibacterial coating, the components of the acquired membrane on the implant surface, the structure of the bacterial cell wall, etc. The current research direction of implant materials aims to reduce bacterial adhesion and promote bone bonding. However, there is no consensus on the physical and chemical properties of implants that meet this requirement. At present, the development trend in implant materials is guided by research of the “core microbiome” of peri-implant inflammation, based on study of the factors related to the adhesion of pathogenic microorganisms to the implant surface, which is organically combined with a variety of modification methods to change the surface-related properties of the implant materials and even to endow the implant with antibacterial properties to reduce or inhibit the adhesion of pathogenic bacteria to the implant.

The oral microbiome has been identified as one of the most diverse microbial communities in the human body, and the ecological imbalance of the oral microbiome can not only induce a variety of oral diseases, such as dental caries, pulpitis, apical periodontitis, and periodontal diseases, but also is closely related to cardiovascular diseases, diabetes and other systemic diseases. The structure of the oral microbiome is affected by multiple factors. This paper reviews and summarizes the effects of genetics, the environment, diet and systemic diseases. Literature reviews have shown that environmental factors play an important role in the structure of the oral microbiome, while the influence of genetic and dietary factors is still controversial. In addition, systemic diseases may also affect the oral microbial community. High-throughput sequencing studies have identified some“core microbiota”, and“core microbiota”in different environments and in different genetic backgrounds will be the next research direction.

Periodontitis is an infectious disease caused by a variety of microorganisms. Fusobacterium nucleatum is closely related to periodontitis with a high detection rate. Fusobacterium nucleatum is able to coaggregate with other microorganisms and attach and invade epithelial cells with the help of adhesins. It can also promote the occurrence and development of periodontal diseases and even systemic diseases by destroying periodontal tissues with virulence factors and metabolites and inducing a host immune response. However, at present, drugs assisting periodontal nonsurgical treatment clinically cannot target specific periodontal pathogens, such as Fusobacterium nucleatum, which may lead to problems such as dysbacteriosis or drug resistance. Therefore, studies on the pathogenic mechanism of Fusobacterium nucleatum provide new ideas for the prevention and treatment of periodontitis. The idea is to develop materials, drugs, or probiotics that target adhesins, virulence factors, and metabolites or cut off each pathogenic pathway of Fusobacterium nucleatum to inhibit its proliferation and inflammatory responses in deep periodontal pockets and achieve a balance with other oral microorganisms, and the host is beneficial for the control of periodontitis.

Nanomaterials usually refer to tiny particles with a diameter of 1-100 nm, which often have unique physicochemical properties and are one of the main areas of research interest for development of dental biomaterials. Nano-calcium phosphate modified dental materials have been widely used in pit and fissure sealing, dental resin restoration, tooth adhesion, and root canal sealing. The current research shows that the dental material modified by nano-calcium phosphate has stronger mechanical properties and shows long-term calcium and phosphorus ion release and excellent ion recharging ability, which can promote the remineralization of tooth hard tissue and has good prospects for application. However, it is difficult to accurately simulate the complex environment of the oral cavity. Therefore, the biocompati-bility, cytotoxicity and effect of clinical application of nano-calcium phosphate modified dental materials still needs further study. This review summarizes and discusses the recent research progress regarding nano-calcium phosphate modified dental materials in the prevention and treatment of dental pulp diseases.

Restorative materials such as conventional glass ionomer cement (CGIC), resin-modified glass ionomer cement (RMGIC), polyacid-modified composite resin (compomer), and giomer have the properties of fluoride release and refill, which may prevent or slow down the progression of caries. The caries resistance of these materials was evaluated according to the following criteria: fluorine-releasing ability, antibacterial activity, mechanical properties and anti-aging properties. The anti-caries effect of these materials mainly depends on the effect of fluoride ions on mineralization. However, materials with strong fluorine release ability, such as CGIC, are mainly used in pediatric dentistry and temporary restoration due to their poor mechanical properties. It is difficult to achieve both fluoride ion release potential and mechanical strength, and there are few materials that can provide ideal mechanical strength while maintaining a high standard of fluoride release. The fluoride releasing and recharging capacity of CGIC, RMGIC, compomer and giomer decrease successively. The trend of material modification, to a certain extent, tends to sacrifice the fluoride release capacity of materials to maintain the ideal mechanical strength. In recent years, scholars have tried to add a variety of fillers to further enhance the anti-cracking ability of materials and add antibacterial agents to compensate for the anti-caries effect to reduce the loss of fluoride release.

With the deepening of the research on the relationship between oral microbiota and systemic diseases, researchers have found that periodontitis is closely related to diabetes, cardiovascular disease, digestive system disease and other systemic diseases. Fusobacterium nucleatum (Fn) and Porphyromonas gingivalis (Pg) are common periodontal pathogens, which play a key role in the occurrence and development of periodontitis. At present, it is also found that Fn and Pg are closely related to the occurrence and development of colorectal cancer (CRC). They can affect the occurrence and development of CRC and the therapeutic effect and prognosis of CRC patients through a variety of ways. It can promote tumor cell proliferation by regulating cell division cycle and inhibiting cell apoptosis, inhibit immune cell function to mediate immune escape and tumor metastasis, and create a pro-inflammatory microenvironment suitable for tumor survival. The study of the effect of periodontal pathogens on the occurrence and development of colorectal cancer and its mechanism also allows us to think about new methods, such as vaccine development, immune agents and antibiotic use to better prevent and treat colorectal cancer and improve the prognosis of patients with colorectal cancer.