1. Product Overview
The Philips Sonicare DiamondClean Smart 9300 electric toothbrush is designed for comprehensive oral care. It features advanced sonic technology, smart sensor feedback, and multiple brushing modes and intensity levels to personalize your brushing experience.

Image: Philips Sonicare DiamondClean Smart 9300 Electric Toothbrush, Model HX9903/15. This image displays the toothbrush handle and brush head.
Key Features:
- Advanced sonic technology for effective cleaning.
- Four brushing modes: Clean, White+, Gum Health, and Deep Clean+.
- Three intensity levels for customized comfort.
- Pressure sensor to alert you when brushing too hard.
- BrushSync™ technology for brush head replacement reminders.
- Connectivity with the Philips Sonicare app for personalized guidance.
- Charging glass and travel case for convenient charging and portability.
Video: This video provides an overview of the Philips Sonicare DiamondClean Smart 9300 Electric Toothbrush features.
2. Setup
2.1 Initial Charge
Before first use, fully charge your Philips Sonicare DiamondClean Smart 9300 toothbrush. The battery lasts up to two weeks on a single charge with regular use (two two-minute brushings per day on standard mode).
- Using the Charging Glass: Place the toothbrush handle into the charging glass. Ensure the charging glass is placed on its base, which is plugged into a power outlet.
- Using the Travel Case: For travel, the included case can charge the toothbrush. Connect the travel case to a USB power source.

Image: The Philips Sonicare DiamondClean Smart 9300 toothbrush handle is shown charging in its glass on a countertop. The charging base is connected to a power outlet.
2.2 Attaching a Brush Head
Align the brush head with the handle and push it down firmly. A small gap between the brush head and the handle is normal.
3. Operating Instructions
3.1 Brushing Modes and Intensity Levels
The toothbrush offers four brushing modes and three intensity levels. Press the power button to turn on the toothbrush. Use the mode selection button to cycle through the available modes:
- Clean: Standard mode for daily cleaning.
- White+: Designed for stain removal.
- Gum Health: Provides gentle yet effective cleaning for gums.
- Deep Clean+: For a refreshing, thorough clean.
To adjust intensity, press the intensity button. The three indicator lights on the handle show the selected intensity level (low, medium, high).

Image: A close-up of the toothbrush handle highlighting the four brushing modes (Clean, White+, Gum Health, Deep Clean+) and three intensity levels.
3.2 Pressure Sensor
The toothbrush features a built-in pressure sensor. If you apply too much pressure while brushing, the light ring at the bottom of the handle will flash, indicating that you should reduce pressure to protect your teeth and gums.

Image: A person is shown brushing their teeth with the Philips Sonicare toothbrush, with the pressure sensor light visible at the base of the handle.
3.3 Philips Sonicare App Connectivity
Connect your toothbrush to the Philips Sonicare app for personalized brushing guidance, real-time feedback, and progress tracking. The app helps you maintain and improve your brushing habits by monitoring coverage, pressure, and scrubbing. It also features a SmarTimer for the recommended 2-minute brushing time and QuadPacer to guide you through different sections of your mouth.
4. Maintenance
4.1 Brush Head Replacement
The BrushSync™ technology will notify you when it's time to replace your brush head. Typically, brush heads should be replaced every three months, or sooner if the bristles appear frayed or worn. To replace, simply pull the old brush head off the handle and snap a new one into place.

Image: The Philips Sonicare toothbrush handle is shown with a brush head detached, illustrating the replaceable design.
4.2 Cleaning
After each use, rinse the brush head and handle under running water. Wipe the handle with a damp cloth. The charging glass can be cleaned by hand or in a dishwasher.
5. Troubleshooting
If you experience any issues with your Philips Sonicare DiamondClean Smart 9300 toothbrush, please refer to the following common solutions:
- Toothbrush not turning on: Ensure the toothbrush is fully charged. Place it in the charging glass or travel case and allow sufficient time to charge.
- Reduced vibration/power: This may indicate a low battery. Recharge the toothbrush. If the issue persists, the brush head might be worn and require replacement.
- Pressure sensor constantly activating: Review your brushing technique to ensure you are not applying excessive force. The light ring will indicate when pressure is too high.
- App connectivity issues: Ensure Bluetooth is enabled on your device and the toothbrush is within range. Try restarting both the app and the toothbrush.
For further assistance, please contact Philips Sonicare customer support.
6. Specifications
| Feature | Detail |
|---|---|
| Product Dimensions | 4.37 x 6.85 x 9.92 inches; 2.31 Pounds |
| Item Model Number | HX9903/15 |
| Batteries | 1 Lithium Ion battery required (included) |
| Manufacturer | Philips Sonicare |
| Age Range (Description) | Adult |
| Special Features | Pressure Sensor, Brushing Timer, Rechargeable, Lightweight, Ergonomic |
| Power Source | Battery Powered |
| Item Firmness Description | Soft |
7. Warranty and Support
The Philips Sonicare DiamondClean Smart 9300 electric toothbrush typically comes with a manufacturer's warranty. Please refer to the product packaging or the official Philips Sonicare website for detailed warranty information and registration. For technical support, replacement parts, or further inquiries, visit the Philips Sonicare support page or contact their customer service directly.